A dietary supplement is a manufactured product intended to supplement a person's diet by taking a

pill Pill or The Pill may refer to: Drugs * Pill (pharmacy), referring to anything small for a specific dose of medicine * "The Pill", a general nickname for the combined oral contraceptive pill Film and television * ''The Pill'' (film), a 2011 fil ...

, capsule, tablet, powder, or liquid. A supplement can provide

nutrient A nutrient is a substance used by an organism to survive, grow and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi and protists. Nutrients can be incorporated into cells for metabolic purposes or excret ...

s either extracted from food sources, or that are synthetic (to increase the quantity of their consumption). The classes of nutrient compounds in supplements include

vitamin Vitamins are Organic compound, organic molecules (or a set of closely related molecules called vitamer, vitamers) that are essential to an organism in small quantities for proper metabolism, metabolic function. Nutrient#Essential nutrients, ...

minerals In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): M ...

fiber Fiber (spelled fibre in British English; from ) is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often inco ...

fatty acid In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated and unsaturated compounds#Organic chemistry, saturated or unsaturated. Most naturally occurring fatty acids have an ...

s, and

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 a ...

s. Dietary supplements can also contain substances that have not been confirmed as being essential to life, and so are not ''nutrients'' per se, but are marketed as having a beneficial biological effect, such as plant

pigment A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another medium; in contrast, dyes are colored sub ...

s or

polyphenol Polyphenols () are a large family of naturally occurring phenols. They are abundant in plants and structurally diverse. Polyphenols include phenolic acids, flavonoids, tannic acid, and ellagitannin, some of which have been used historically as ...

s. Animals can also be a source of supplement ingredients, such as

collagen Collagen () is the main structural protein in the extracellular matrix of the connective tissues of many animals. It is the most abundant protein in mammals, making up 25% to 35% of protein content. Amino acids are bound together to form a trip ...

from chickens or fish for example. These are also sold individually and in combination, and may be combined with nutrient ingredients. The

European Commission The European Commission (EC) is the primary Executive (government), executive arm of the European Union (EU). It operates as a cabinet government, with a number of European Commissioner, members of the Commission (directorial system, informall ...

has also established harmonized rules to help insure that food supplements are safe and appropriately labeled. Creating an industry estimated to have a value of $151.9 billion in 2021, there are more than 50,000 dietary supplement products marketed in the United States, where about 50% of the American adult population consumes dietary supplements.

Multivitamin A multivitamin is a preparation intended to serve as a dietary supplement with vitamins, dietary minerals, and other nutritional elements. Such preparations are available in the form of tablets, capsules, pastilles, powders, liquids, gummies, o ...

s are the most commonly used product among types of dietary supplements. The United States

National Institutes of Health The National Institutes of Health (NIH) is the primary agency of the United States government responsible for biomedical and public health research. It was founded in 1887 and is part of the United States Department of Health and Human Service ...

states that some supplements may help provide essential nutrients or support overall

health Health has a variety of definitions, which have been used for different purposes over time. In general, it refers to physical and emotional well-being, especially that associated with normal functioning of the human body, absent of disease, p ...

and performance for those with limited dietary variety who receive approval from their medical provider. In the United States, it is against federal regulations for supplement manufacturers to claim that these products prevent or treat any disease. Companies are allowed to use what is referred to as "Structure/Function" wording if there is substantiation of

scientific evidence Scientific evidence is evidence that serves to either support or counter a scientific theory or hypothesis, although scientists also use evidence in other ways, such as when applying theories to practical problems. "Discussions about empirical ev ...

for a supplement providing a potential health effect. An example would be "_____ helps maintain healthy joints", but the label must bear a disclaimer that the

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...

(FDA) "has not evaluated the claim" and that the dietary supplement product is not intended to "diagnose, treat, cure or prevent any disease", because only a

drug A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via insufflation (medicine), inhalation, drug i ...

can legally make such a claim. The FDA enforces these regulations and also prohibits the sale of supplements and supplement ingredients that are dangerous, or supplements not made according to standardized

good manufacturing practice Current good manufacturing practices (cGMP) are those conforming to the guidelines recommended by relevant agencies. Those agencies control the authorization and licensing of the manufacture and sale of food and beverages, cosmetics, pharmaceutic ...

s (GMPs).

Definition

In the United States, the Dietary Supplement Health and Education Act of 1994 provides this description: "The Dietary Supplement Health and Education Act of 1994 (DSHEA) defines the term "dietary supplement" to mean a product (other than tobacco) intended to supplement the diet that bears or contains one or more of the following dietary ingredients: a vitamin, a mineral, an herb or other botanical, an amino acid, a dietary substance for use by man to supplement the diet by increasing the total dietary intake, or a concentrate,

metabolite In biochemistry, a metabolite is an intermediate or end product of metabolism. The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...

, constituent,

extract An extract (essence) is a substance made by extracting a part of a raw material, often by using a solvent such as ethanol, oil or water. Extracts may be sold as tinctures or absolutes or dried and powdered. The aromatic principles of ma ...

, or combination of any of the aforementioned ingredients. Furthermore, a dietary supplement must be labeled as a dietary supplement and be intended for ingestion and must not be represented for use as conventional food or as a sole item of a meal or of the diet. In addition, a dietary supplement cannot be approved or authorized for investigation as a new drug,

antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...

, or biologic, unless it was marketed as a food or a dietary supplement before such approval or authorization. Under DSHEA, dietary supplements are deemed to be food, except for purposes of the drug definition." Per DSHEA, dietary supplements are consumed orally, and are mainly defined by what they are not: conventional foods (including

meal replacement A meal replacement is a drink, bar, soup, etc. intended as a substitute for a solid food, usually with controlled quantities of calories and nutrients. Some drinks come in powdered form or pre-mixed health shakes that can be cheaper than solid fo ...

s),

medical food Medical food is food that is specially formulated and intended for the dietary management of a disease that has distinctive nutritional needs that cannot be met by normal diet alone. In the United States, it was defined in the Food and Drug Admin ...

preservative A preservative is a substance or a chemical that is added to products such as food products, beverages, pharmaceutical drugs, paints, biological samples, cosmetics, wood, and many other products to prevent decomposition by microbial growth or ...

s or

pharmaceutical drugs Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the ...

. Products intended for use as a

nasal spray Nasal sprays are used to deliver medications Route of administration#Local, locally in the nasal cavities or systemic administration, systemically. They are used locally for conditions such as nasal congestion and allergic rhinitis. In some sit ...

, or topically, as a lotion applied to the skin, do not qualify. FDA-approved drugs cannot be ingredients in dietary supplements. Supplement products are or contain

vitamins Vitamins are organic molecules (or a set of closely related molecules called vitamers) that are essential to an organism in small quantities for proper metabolic function. Essential nutrients cannot be synthesized in the organism in suff ...

, nutritionally essential minerals,

essential fatty acid Essential fatty acids, or EFAs, are fatty acids that are required by humans and other animals for normal physiological function that cannot be synthesized in the body.⁠ As they are not synthesized in the body, the essential fatty acids al ...

s and non-nutrient substances extracted from plants or animals or

fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

or bacteria, or in the instance of

probiotic Probiotics are live microorganisms that provide health benefits when consumed, generally by improving or restoring the microbiota in the gut. Probiotics are considered generally safe to consume, but may cause bacteria– host interactions ...

s, are live bacteria. Dietary supplement ingredients may also be synthetic copies of naturally occurring substances (for example:

melatonin Melatonin, an indoleamine, is a natural compound produced by various organisms, including bacteria and eukaryotes. Its discovery in 1958 by Aaron B. Lerner and colleagues stemmed from the isolation of a substance from the pineal gland of cow ...

). All products with these ingredients are required to be labeled as dietary supplements. Like foods and unlike drugs, no government approval is required to make or sell dietary supplements; the manufacturer confirms the safety of dietary supplements but the government does not; and rather than requiring risk–benefit analysis to prove that the product can be sold like a drug, such assessment is only used by the FDA to decide that a dietary supplement is unsafe and should be removed from market.

Types

Vitamins

A vitamin is an

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

required by an

organism An organism is any life, living thing that functions as an individual. Such a definition raises more problems than it solves, not least because the concept of an individual is also difficult. Many criteria, few of them widely accepted, have be ...

as a vital

in limited amounts.Lieberman, S and Bruning, N (1990). ''The Real Vitamin & Mineral Book''. NY: Avery Group, 3, . An organic chemical compound (or related set of compounds) is called a vitamin when it cannot be synthesized in sufficient quantities by an organism and must be obtained from the diet. The term is conditional both on the circumstances and on the particular organism. For example,

ascorbic acid Ascorbic acid is an organic compound with formula , originally called hexuronic acid. It is a white solid, but impure samples can appear yellowish. It dissolves freely in water to give mildly acidic solutions. It is a mild reducing agent. Asco ...

(vitamin C) is a vitamin for anthropoid primates, humans,

guinea pig The guinea pig or domestic guinea pig (''Cavia porcellus''), also known as the cavy or domestic cavy ( ), is a species of rodent belonging to the genus ''Cavia'', family Caviidae. Animal fancy, Breeders tend to use the name "cavy" for the ani ...

s and bats, but not for other mammals. Vitamin D is not an essential nutrient for people who get sufficient exposure to

ultraviolet light Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of th ...

, either from the sun or an artificial source, as they synthesize vitamin D in skin. Humans require thirteen vitamins in their diet, most of which are actually groups of related molecules, "vitamers", (e.g. vitamin E includes

tocopherol Tocopherols (; TCP) are a class of organic compounds comprising various methylated phenols, many of which have vitamin E activity. Because the vitamin activity was first identified in 1936 from a dietary fertility factor in rats, it was named ''t ...

s and

tocotrienol Tocotrienols are plant-derived natural products belonging to the vitamin E family of diterpenoids. They exist as four isomers (alpha, beta, gamma, delta), each differing in the number and position of methyl groups on their chromanol ring. Toc ...

s, vitamin K includes vitamin K₁ and K₂). The list: vitamins A, C, D, E, K, Thiamine (B₁), Riboflavin (B₂), Niacin (B₃), Pantothenic Acid (B₅), Vitamin B₆, Biotin (B₇), Folate (B₉) and Vitamin B₁₂. Vitamin intake below recommended amounts can result in signs and symptoms associated with vitamin deficiency. There is little evidence of benefit when vitamins are consumed as a dietary supplement by those who are healthy and have a nutritionally adequate diet. The U.S. Institute of Medicine sets

tolerable upper intake level The Dietary Reference Intake (DRI) is a system of nutrition recommendations from the National Academy of Medicine (NAM) of the National Academies (United States). It was introduced in 1997 in order to broaden the existing guidelines known as Recom ...

s (ULs) for some of the vitamins. This does not prevent dietary supplement companies from selling products with content per serving higher than the ULs. For example, the UL for vitamin D is 100 μg (4,000 IU), but products are available without prescription at 10,000 IU.

Minerals

Minerals are the

exogenous In a variety of contexts, exogeny or exogeneity () is the fact of an action or object originating externally. It is the opposite of endogeneity or endogeny, the fact of being influenced from within a system. Economics In an economic model, an ...

chemical element A chemical element is a chemical substance whose atoms all have the same number of protons. The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8: each oxygen atom has 8 protons in its ...

s indispensable for life. Four minerals –

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

hydrogen Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

, and

nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

– are essential for life but are so ubiquitous in food and drink that these are not considered nutrients and there are no recommended intakes for these as minerals. The need for nitrogen is addressed by requirements set for protein, which is composed of nitrogen-containing amino acids.

Sulfur Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...

is essential, but for humans, not identified as having a recommended intake per se. Instead, recommended intakes are identified for the sulfur-containing amino acids

methionine Methionine (symbol Met or M) () is an essential amino acid in humans. As the precursor of other non-essential amino acids such as cysteine and taurine, versatile compounds such as SAM-e, and the important antioxidant glutathione, methionine play ...

and

cysteine Cysteine (; symbol Cys or C) is a semiessential proteinogenic amino acid with the chemical formula, formula . The thiol side chain in cysteine enables the formation of Disulfide, disulfide bonds, and often participates in enzymatic reactions as ...

. There are dietary supplements that provide sulfur, such as

taurine Taurine (), or 2-aminoethanesulfonic acid, is a naturally occurring amino sulfonic acid that is widely distributed in animal tissues. It is a major constituent of bile and can be found in the large intestine. It is named after Latin (cogna ...

and

methylsulfonylmethane Dimethyl sulfone (DMSO2) is an organosulfur compound with the formula . It is also known by several other names including methyl sulfone and (especially in alternative medicine) methylsulfonylmethane (MSM). This colorless solid features the sulfo ...

. The essential nutrient minerals for humans, listed in order by weight needed to be at the

Recommended Dietary Allowance In the U.S. and Canada, the Reference Daily Intake (RDI) is used in nutrition labeling on food and dietary supplement products to indicate the daily intake level of a nutrient that is considered to be sufficient to meet the requirements of 97� ...

Adequate Intake The Dietary Reference Intake (DRI) is a system of nutrition recommendations from the National Academy of Medicine (NAM) of the National Academies (United States). It was introduced in 1997 in order to broaden the existing guidelines known as Reco ...

are

potassium Potassium is a chemical element; it has Symbol (chemistry), symbol K (from Neo-Latin ) and atomic number19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to ...

chlorine Chlorine is a chemical element; it has Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between ...

sodium Sodium is a chemical element; it has Symbol (chemistry), symbol Na (from Neo-Latin ) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the peri ...

calcium Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to it ...

phosphorus Phosphorus is a chemical element; it has Chemical symbol, symbol P and atomic number 15. All elemental forms of phosphorus are highly Reactivity (chemistry), reactive and are therefore never found in nature. They can nevertheless be prepared ar ...

magnesium Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 ...

, iron,

zinc Zinc is a chemical element; it has symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic tabl ...

manganese Manganese is a chemical element; it has Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. It is a transition m ...

, copper,

iodine Iodine is a chemical element; it has symbol I and atomic number 53. The heaviest of the stable halogens, it exists at standard conditions as a semi-lustrous, non-metallic solid that melts to form a deep violet liquid at , and boils to a vi ...

chromium Chromium is a chemical element; it has Symbol (chemistry), symbol Cr and atomic number 24. It is the first element in Group 6 element, group 6. It is a steely-grey, Luster (mineralogy), lustrous, hard, and brittle transition metal. Chromium ...

molybdenum Molybdenum is a chemical element; it has Symbol (chemistry), symbol Mo (from Neo-Latin ''molybdaenum'') and atomic number 42. The name derived from Ancient Greek ', meaning lead, since its ores were confused with lead ores. Molybdenum minerals hav ...

selenium Selenium is a chemical element; it has symbol (chemistry), symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elem ...

and

cobalt Cobalt is a chemical element; it has Symbol (chemistry), symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. ...

(the last as a component of vitamin B₁₂). There are other minerals which are essential for some plants and animals, but may or may not be essential for humans, such as

boron Boron is a chemical element; it has symbol B and atomic number 5. In its crystalline form it is a brittle, dark, lustrous metalloid; in its amorphous form it is a brown powder. As the lightest element of the boron group it has three ...

and

silicon Silicon is a chemical element; it has symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic lustre, and is a tetravalent metalloid (sometimes considered a non-metal) and semiconductor. It is a membe ...

. Essential and purportedly essential minerals are marketed as dietary supplements, individually and in combination with vitamins and other minerals. Although as a general rule, dietary supplement labeling and marketing are not allowed to make disease prevention or treatment claims, the U.S. FDA has for some foods and dietary supplements reviewed the science, concluded that there is significant scientific agreement, and published specifically worded allowed health claims. An initial ruling allowing a health claim for calcium dietary supplements and

osteoporosis Osteoporosis is a systemic skeletal disorder characterized by low bone mass, micro-architectural deterioration of bone tissue leading to more porous bone, and consequent increase in Bone fracture, fracture risk. It is the most common reason f ...

was later amended to include calcium supplements with or without vitamin D, effective January 1, 2010. Examples of allowed wording are shown below. To qualify for the calcium health claim, a dietary supplement must contain at least 20% of the Reference Dietary Intake, which for calcium means at least 260 mg/serving. * "Adequate calcium throughout life, as part of a well-balanced diet, may reduce the risk of osteoporosis." * "Adequate calcium as part of a healthful diet, along with physical activity, may reduce the risk of osteoporosis in later life." * "Adequate calcium and vitamin D throughout life, as part of a well-balanced diet, may reduce the risk of osteoporosis." * "Adequate calcium and vitamin D as part of a healthful diet, along with physical activity, may reduce the risk of osteoporosis in later life." In the same year, the European Food Safety Authority also approved a dietary supplement health claim for calcium and vitamin D and the reduction of the risk of osteoporotic fractures by reducing bone loss. The U.S. FDA also approved Qualified Health Claims (QHCs) for various health conditions for calcium, selenium and chromium picolinate. QHCs are supported by scientific evidence, but do not meet the more rigorous "significant scientific agreement" standard required for an authorized health claim. If dietary supplement companies choose to make such a claim then the FDA stipulates the exact wording of the QHC to be used on labels and in marketing materials. The wording can be onerous: "One study suggests that selenium intake may reduce the risk of

bladder cancer Bladder cancer is the abnormal growth of cells in the bladder. These cells can grow to form a tumor, which eventually spreads, damaging the bladder and other organs. Most people with bladder cancer are diagnosed after noticing blood in thei ...

in women. However, one smaller study showed no reduction in risk. Based on these studies, FDA concludes that it is highly uncertain that selenium supplements reduce the risk of bladder cancer in women."

Proteins and amino acids

Protein-containing supplements, either ready-to-drink or as powders to be mixed into water, are marketed as aids to people recovering from illness or injury, those hoping to thwart the

sarcopenia Sarcopenia ( ICD-10-CM code M62.84) is a type of muscle loss that occurs with aging and/or immobility. It is characterized by the degenerative loss of skeletal muscle mass, quality, and strength. The rate of muscle loss is dependent on exer ...

of old age, to athletes who believe that strenuous physical activity increases protein requirements, to people hoping to lose weight while minimizing muscle loss, i.e., conducting a

protein-sparing modified fast A protein-sparing modified fast or PSMF diet is a type of a very-low-calorie diet (<800 kcal per day) with a high proportion of protein calories and simultaneous restriction of carbohydrate and fat. It includes a

, and to people who want to increase muscle size for performance and appearance.

Whey protein Whey protein is a mixture of proteins isolated from whey, the liquid material created as a by-product of cheese production. The proteins consist of α-lactalbumin, β-lactoglobulin, serum albumin and immunoglobulins. Glycomacropeptide also m ...

is a popular ingredient, but products may also incorporate

casein Casein ( , from Latin ''caseus'' "cheese") is a family of related phosphoproteins (CSN1S1, αS1, aS2, CSN2, β, K-casein, κ) that are commonly found in mammalian milk, comprising about 80% of the proteins in cow's milk and between 20% and 60% of ...

soy The soybean, soy bean, or soya bean (''Glycine max'') is a species of legume native to East Asia, widely grown for its edible bean. Soy is a staple crop, the world's most grown legume, and an important animal feed. Soy is a key source of f ...

pea Pea (''pisum'' in Latin) is a pulse or fodder crop, but the word often refers to the seed or sometimes the pod of this flowering plant species. Peas are eaten as a vegetable. Carl Linnaeus gave the species the scientific name ''Pisum sativum' ...

hemp Hemp, or industrial hemp, is a plant in the botanical class of ''Cannabis sativa'' cultivars grown specifically for industrial and consumable use. It can be used to make a wide range of products. Along with bamboo, hemp is among the fastest ...

or rice protein. A meta-analysis found a moderate degree of evidence in favor of whey protein supplements use as a safe and effective adjunct to an athlete's training and recovery, including benefits for

endurance Endurance (also related to sufferance, forbearance, resilience, constitution, fortitude, persistence, tenacity, steadfastness, perseverance, stamina, and hardiness) is the ability of an organism to exert itself and remain active for a ...

, average power,

muscle mass Skeletal muscle (commonly referred to as muscle) is one of the three types of vertebrate muscle tissue, the others being cardiac muscle and smooth muscle. They are part of the voluntary muscular system and typically are attached by tendons to bo ...

, and reduced perceived

exercise intensity Exercise intensity refers to how much energy is expended when exercise, exercising. Perceived intensity varies with each person. It has been found that intensity has an effect on what fuel the body uses and what kind of adaptations the body mak ...

. According to US and Canadian

Dietary Reference Intake The Dietary Reference Intake (DRI) is a system of nutrition recommendations from the National Academy of Medicine (NAM) of the National Academies (United States). It was introduced in 1997 in order to broaden the existing guidelines known as Rec ...

guidelines, the protein

(RDA) for adults is based on 0.8 grams protein per kilogram body weight. The recommendation is for sedentary and lightly active people. Scientific reviews can conclude that a high protein diet, when combined with exercise, will increase muscle mass and strength, or conclude the opposite. The International Olympic Committee recommends protein intake targets for both strength and endurance athletes at about 1.2–1.8 g/kg body mass per day. One review proposed a maximum daily protein intake of approximately 25% of energy requirements, i.e., approximately 2.0 to 2.5 g/kg. The same protein ingredients marketed as dietary supplements can be incorporated into

and

products, but those are regulated and labeled differently from supplements. In the United States, "meal replacement" products are foods and are labeled as such. These typically contain protein, carbohydrates, fats, vitamins and minerals. There may be content claims such as "good source of protein", "low fat" or "lactose free". Medical foods, also nutritionally complete, are designed to be used while a person is under the care of a physician or other licensed healthcare professional. Liquid medical food products – for example,

Ensure Ensure is an American brand of nutritional supplements and meal replacements manufactured by Abbott Laboratories. A 237-ml (8-fl oz) bottle of Ensure Original contains 220 calories, six grams of fat, 15 grams of sugar, and nine grams of prot ...

– are available in regular and high protein versions. Proteins are chains of

s. Nine of these proteinogenic amino acids are considered essential for humans because they cannot be produced from other compounds by the human body and so must be taken in as food. Recommended intakes, expressed as milligrams per kilogram of body weight per day, have been established. Other amino acids may be conditionally essential for certain ages or medical conditions. Amino acids, individually and in combinations, are sold as dietary supplements. The claim for supplementing with the

branched-chain amino acid A branched-chain amino acid (BCAA) is an amino acid having an aliphatic substituent, side-chain with a branch (a central carbon atom bound to three or more carbon atoms). Among the proteinogenic amino acids, there are three BCAAs: leucine, isoleu ...

s leucine, valine and isoleucine is for stimulating muscle protein synthesis. A review of the literature concluded this claim was unwarranted. In elderly people, supplementation with just

leucine Leucine (symbol Leu or L) is an essential amino acid that is used in the biosynthesis of proteins. Leucine is an α-amino acid, meaning it contains an α-amino group (which is in the protonated −NH3+ form under biological conditions), an α-Car ...

resulted in a modest (0.99 kg) increase in lean body mass. The non-essential amino acid

arginine Arginine is the amino acid with the formula (H2N)(HN)CN(H)(CH2)3CH(NH2)CO2H. The molecule features a guanidinium, guanidino group appended to a standard amino acid framework. At physiological pH, the carboxylic acid is deprotonated (−CO2−) a ...

, consumed in sufficient amounts, is thought to act as a donor for the synthesis of nitric oxide, a vasodilator. A review confirmed blood pressure lowering.

Taurine Taurine (), or 2-aminoethanesulfonic acid, is a naturally occurring amino sulfonic acid that is widely distributed in animal tissues. It is a major constituent of bile and can be found in the large intestine. It is named after Latin (cogna ...

, a popular dietary supplement ingredient with claims made for sports performance, is technically not an amino acid. It is synthesized in the body from the amino acid

Bodybuilding supplements

Beauty supplements

Beauty supplements, particularly those aimed at improving the health of skin, hair, and nails, are commonly marketed within the wellness and supplement markets. These products typically include ingredients, such as

, which is reputed to improve the appearance and condition of skin, hair, and nails. Other typical ingredients include

biotin Biotin (also known as vitamin B7 or vitamin H) is one of the B vitamins. It is involved in a wide range of metabolic processes, both in humans and in other organisms, primarily related to the utilization of fats, carbohydrates, and amino acids. ...

keratin Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. It is the key structural material making up Scale (anatomy), scales, hair, Nail (anatomy), nails, feathers, horn (anatomy), horns, claws, Hoof, hoove ...

, and

omega-3 fatty acid Omega−3 fatty acids, also called omega−3 oils, ω−3 fatty acids or ''n''−3 fatty acids, are polyunsaturated fatty acids (PUFAs) characterized by the presence of a double bond three atoms away from the terminal methyl group in their ...

s, which are promoted for their alleged benefits to skin and hair health. Demand for these beauty supplements has risen markedly in the 21st century. Despite the apparent rise in demand, scientific evidence supporting the efficacy of ingredients like biotin for the purpose of hair growth remains unproven.

Essential fatty acids

Fish oil is a commonly used fatty acid supplement because it is a source of

s. Fatty acids are strings of carbon atoms, having a range of lengths. If links are all single (C−C), then the fatty acid is called '' saturated''; with one double bond (C=C), it is called '' monounsaturated''; if there are two or more double bonds (C=C=C), it is called '' polyunsaturated''. Only two fatty acids, both polyunsaturated, are considered essential to be obtained from the diet, as the others are synthesized in the body. The "essential" fatty acids are alpha-linolenic acid (ALA), an omega-3 fatty acid, and

linoleic acid Linoleic acid (LA) is an organic compound with the formula . Both alkene groups () are ''cis''. It is a fatty acid sometimes denoted 18:2 (n−6) or 18:2 ''cis''-9,12. A linoleate is a salt or ester of this acid. Linoleic acid is a polyunsat ...

(LA), an

omega-6 fatty acid Omega−6 fatty acids (also referred to as ω−6 fatty acids or ''n''−6 fatty acids) are a family of polyunsaturated fatty acids (PUFA) that share a final carbon-carbon double bond in the ''n''−6 position, that is, the sixth bond, counti ...

. ALA can be elongated in the body to create other omega-3 fatty acids:

eicosapentaenoic acid Eicosapentaenoic acid (EPA; also icosapentaenoic acid) is an omega−3 fatty acid. In physiological literature, it is given the name 20:5(''n''−3). It also has the trivial name timnodonic acid. In chemical structure, EPA is a carboxylic acid wi ...

(EPA) and

docosahexaenoic acid Docosahexaenoic acid (DHA) is an omega−3 fatty acid that is an important component of the human brain, cerebral cortex, skin, and retina. It is given the fatty acid notation 22:6(''n''−3). It can be synthesized from alpha-linolenic acid or ...

(DHA). Plant oils, particularly seed and nut oils, contain ALA. Food sources of EPA and DHA are oceanic fish, whereas dietary supplement sources include fish oil, krill oil and

marine algae Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine current power * Marine debris * Marine energy * Marine habitats * M ...

extracts. The

European Food Safety Authority The European Food Safety Authority (EFSA) is the agency of the European Union (EU) that provides independent scientific advice and communicates on existing and emerging risks associated with the food chain. EFSA was established in February 2002 ...

(EFSA) identifies 250 mg/day for a combined total of EPA and DHA as Adequate Intake, with a recommendation that women pregnant or lactating consume an additional 100 to 200 mg/day of DHA. In the United States and Canada are

s for ALA and LA over various stages of life, but there are no intake levels specified for EPA and/or DHA. Supplementation with EPA and/or DHA does not appear to affect the risk of death, cancer or heart disease. Furthermore, studies of fish oil supplements have failed to support claims of preventing

heart attacks A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops in one of the coronary arteries of the heart, causing infarction (tissue death) to the heart muscle. The most common symptom is retr ...

or strokes. In 2017, the American Heart Association issued a science advisory stating that it could not recommend use of omega-3 fish oil supplements for primary prevention of

cardiovascular disease Cardiovascular disease (CVD) is any disease involving the heart or blood vessels. CVDs constitute a class of diseases that includes: coronary artery diseases (e.g. angina, heart attack), heart failure, hypertensive heart disease, rheumati ...

or stroke, although it reaffirmed supplementation for people who have a history of

coronary heart disease Coronary artery disease (CAD), also called coronary heart disease (CHD), or ischemic heart disease (IHD), is a type of cardiovascular disease, heart disease involving Ischemia, the reduction of blood flow to the cardiac muscle due to a build-up ...

. Manufacturers have begun to include long chain polyunsaturated fatty acids DHA and

arachidonic acid Arachidonic acid (AA, sometimes ARA) is a polyunsaturated omega−6 fatty acid 20:4(ω−6), or 20:4(5,8,11,14). It is a precursor in the formation of leukotrienes, prostaglandins, and thromboxanes. Together with omega−3 fatty acids an ...

(AA) into their formula milk for newborns, however, a 2017 review found that supplementation with DHA and AA does not appear to be harmful or beneficial to formula-fed infants.

Natural products

Dietary supplements can be manufactured using intact sources or

s from plants, animals, algae, fungi or lichens, including such examples as

ginkgo biloba ''Ginkgo biloba'', commonly known as ginkgo or gingko ( ), also known as the maidenhair tree, is a species of gymnosperm tree native to East Asia. It is the last living species in the order Ginkgoales, which first appeared over 290 million year ...

curcumin Curcumin is a bright yellow chemical produced by plants of the ''Curcuma longa'' species. It is the principal curcuminoid of turmeric (''Curcuma longa''), a member of the ginger family, Zingiberaceae. It is sold as a herbal supplement, cosmetic ...

cranberry Cranberries are a group of evergreen dwarf shrubs or trailing vines in the subgenus ''Oxycoccus'' of the genus ''Vaccinium''. Cranberries are low, creeping shrubs or vines up to long and in height; they have slender stems that are not th ...

St. John's wort ''Hypericum perforatum'', commonly known as St. John's wort (sometimes perforate St. John's wort or common St. John's wort), is a flowering plant in the family Hypericaceae. It is a hairless, Perennial, perennial herb with woody Root, roots, y ...

ginseng Ginseng () is the root of plants in the genus ''Panax'', such as South China ginseng (''Panax notoginseng, P. notoginseng''), Korean ginseng (''Panax ginseng, P. ginseng''), and American ginseng (''American ginseng, P. quinquefol ...

resveratrol Resveratrol (3,5,4′-trihydroxy-''trans''-stilbene) is a stilbenoid, a type of natural phenol or polyphenol and a phytoalexin produced by several plants in response to injury or when the plant is under attack by pathogens, such as bacterium, ba ...

glucosamine Glucosamine (C6H13NO5) is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of two polysaccharides, chitosan and chitin. Glucosamine is one of the mo ...

and

. Products bearing promotional claims of health benefits are sold without requiring a prescription in

pharmacies Pharmacy is the science and practice of discovering, producing, preparing, dispensing, reviewing and monitoring medications, aiming to ensure the safe, effective, and affordable use of medication, medicines. It is a miscellaneous science as it ...

, supermarkets, specialist shops, military commissaries,

buyers club A buyers club or buying club is a Club (organization), club organized to pool members' collective buying power, enabling them to make purchases at lower prices than are generally available, or to purchase goods that might be difficult to obtain ind ...

direct selling Direct selling is a business model that involves a party of people buying products from a parent organization and selling them directly to customers. It can take the form of either single-level marketing (in which a direct seller makes money pu ...

organizations, and the internet. While most of these products have a long history of use in

herbalism Herbal medicine (also called herbalism, phytomedicine or phytotherapy) is the study of pharmacognosy and the use of medicinal plants, which are a basis of traditional medicine. Scientific evidence for the effectiveness of many herbal treatments ...

and various forms of traditional medicine, concerns exist about their actual efficacy, safety and consistency of quality. Canada has published a manufacturer and consumer guide describing quality, licensing, standards, identities, and common contaminants of natural products. In 2019, sales of herbal supplements just in the United States alone were $9.6 billion, with the market growing at approximately 8.6% per year, with

cannabidiol Cannabidiol (CBD) is a phytocannabinoid, one of 113 identified cannabinoids in ''Cannabis'', along with tetrahydrocannabinol (THC), and accounts for up to 40% of the plant's extract. Medically, it is an anticonvulsant used to treat multiple f ...

and mushroom product sales as the highest. Italy, Germany, and Eastern European countries were leading consumers of botanical supplements in 2016, with European Union market growth forecast to be $8.7 billion by 2020.

Probiotics

Claimed benefits of using

supplements are not supported by sufficient clinical evidence. Meta-analysis studies have reported a modest reduction of antibiotic-associated diarrhea and acute diarrhea in children taking probiotics. There is limited evidence in support of adults using mono-strain and multi-strain containing probiotics for the alleviation of symptoms associated with

irritable bowel syndrome Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by a group of symptoms that commonly include abdominal pain, abdominal bloating, and changes in the consistency of bowel movements. These symptoms may ...

. Probiotic supplements are generally regarded as safe.

Fertility

A meta-analysis provided preliminary evidence that men treated with supplements containing

s, coenzyme Q₁₀ or

carnitine Carnitine is a quaternary ammonium compound involved in metabolism in most mammals, plants, and some bacteria. In support of energy metabolism, carnitine transports long-chain fatty acids from the cytosol into mitochondria to be oxidized for f ...

s reported improvements in total sperm count, concentration, motility, and morphology. A review concluded that omega-3 taken through supplements and diet might improve semen quality in infertile men. A 2021 review also supported selenium, zinc, omega-3 fatty acids, coenzyme Q₁₀ or carnitines, but warned that "excessive use of antioxidants may be detrimental to the spermatic function and many of the over-the-counter supplements are not scientifically proven to improve fertility." There is low quality and insufficient evidence for the use of oral antioxidant supplements as a viable treatment for

subfertile In biology, infertility is the inability of a male and female organism to reproduce. It is usually not the natural state of a healthy organism that has reached sexual maturity, so children who have not undergone puberty, which is the body's star ...

woman. A review provided evidence that taking

dehydroepiandrosterone Dehydroepiandrosterone (DHEA), also known as androstenolone, is an endogenous steroid hormone precursor. It is one of the most abundant circulating steroids in humans. DHEA is produced in the adrenal glands, the gonads, and the brain. It funct ...

before starting an ''in vitro'' fertilization series may increase pregnancy rates and decrease miscarriage likelihood.

Prenatal

Prenatal vitamins Prenatal vitamins, also known as prenatal supplements, are vitamin and mineral supplements intended to be taken before and during pregnancy and during postnatal lactation. Although not intended to replace a healthy diet, prenatal vitamins provi ...

are dietary supplements commonly given to pregnant women to supply nutrients that may reduce health complications for the mother and

fetus A fetus or foetus (; : fetuses, foetuses, rarely feti or foeti) is the unborn offspring of a viviparous animal that develops from an embryo. Following the embryonic development, embryonic stage, the fetal stage of development takes place. Pren ...

. Although prenatal vitamins are not meant to substitute for dietary nutrition, prenatal supplementation may be beneficial for pregnant women at risk of nutrient deficiencies because of diet limitations or restrictions. The most common components in prenatal vitamins include vitamins B₆,

folate Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing and ...

, B₁₂, C, D, E,

iron Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...

and

. Sufficient intake of vitamin B₆ can lower the risk of early pregnancy loss and relieve symptoms of

morning sickness Morning sickness, also called nausea and vomiting of pregnancy (NVP), is a symptom of pregnancy. Despite the name, nausea or vomiting can occur at any time during the day. Typically the symptoms occur between the 4th and 16th weeks of pregnan ...

. Folate is also an essential nutrient for pregnant women to prevent

neural tube defect Neural tube defects (NTDs) are a group of birth defects in which an opening in the spine or cranium remains from early in human development. In the third week of pregnancy called gastrulation, specialized cells on the dorsal side of the embryo ...

s. In 2006, the World Health Organization endorsed the recommendation for women of child-bearing age to consume 400

microgram In the metric system, a microgram or microgramme is a unit of mass equal to one millionth () of a gram. The unit symbol is μg according to the International System of Units (SI); the recommended symbol in the United States and United Kingdom wh ...

s of folate through the diet daily if planning a pregnancy. A 2013 review found folic acid supplementation during pregnancy did not affect the mother's health other than a risk reduction on low pre-delivery serum folate and megaloblastic anemia. There is little evidence to suggest that vitamin D supplementation improves prenatal outcomes in hypertensive disorders and

gestational diabetes Gestational diabetes is a condition in which a woman without diabetes develops hyperglycemia, high blood sugar levels during pregnancy. Gestational diabetes generally results in few symptoms. Obesity increases the rate of pre-eclampsia, cesarea ...

. Evidence does not support the routine use of vitamin E supplementation during pregnancy to prevent adverse events, such as preterm birth, fetal or neonatal death, or maternal hypertensive disorders. Iron supplementation can lower the risk of

iron deficiency anemia Iron-deficiency anemia is anemia caused by a lack of iron. Anemia is defined as a decrease in the number of red blood cells or the amount of hemoglobin in the blood. When onset is slow, symptoms are often vague such as feeling tired, weak, sh ...

for pregnant women. In 2020, the World Health Organization updated recommendations for adequate calcium levels during pregnancy to prevent hypertensive disorders.

Pharmacotherapy

Individuals with hypokalemic sensory overstimulation are sometimes diagnosed as having attention deficit hyperactivity disorder (ADHD), raising the possibility that a subtype of ADHD has a cause that can be understood mechanistically and treated in a novel way. The sensory overload is treatable with oral potassium gluconate.

Industry

In 2020, the American market for dietary supplements was valued at $140.3 billion, with the economic impact in the United States for 2016 estimated at $122 billion, including employment wages and taxes. A 2020 analysis projected that the global market for

s and dietary supplement products would reach $196.6 billion by 2028, where the growth in

market size In economics, a market is a composition of systems, institutions, procedures, social relations or infrastructures whereby parties engage in exchange. While parties may exchange goods and services by barter, most markets rely on sellers offering ...

is largely attributed to recent technological advancements in product manufacturing, increased demand for products advertised as healthy, increased product availability, and

population aging Population ageing is an overall change in the ages of a population. This can typically be summarised in a single parameter as an increase in the median age. Causes are a long-term decline in fertility rates and a decline in mortality rates. Most ...

Adulteration, contamination and mislabeling

Over the period 2008 to 2011, the

Government Accountability Office The United States Government Accountability Office (GAO) is an independent, nonpartisan government agency within the legislative branch that provides auditing, evaluative, and investigative services for the United States Congress. It is the s ...

(GAO) of the United States received 6,307 reports of health problems (identified as

adverse event In pharmaceuticals, an adverse event (AE) is any unexpected or harmful medical occurrence that happens to a patient during medical treatment or a clinical trial. Unlike direct side effects, an adverse event does not necessarily mean the medicati ...

s) from use of dietary supplements containing a combination of ingredients in manufactured vitamins, minerals or other supplement products, with 92% of tested herbal supplements containing lead and 80% containing other chemical contaminants. Using

undercover A cover in foreign, military or police human intelligence or counterintelligence is the ostensible identity and role or position in an infiltrated organization assumed by a covert agent during a covert operation. Official cover In espionage, a ...

staff, the GAO also found that supplement retailers intentionally engaged in "unequivocal deception" to sell products advertised with baseless health claims, particularly to elderly consumers.

Consumer Reports Consumer Reports (CR), formerly Consumers Union (CU), is an American nonprofit consumer organization dedicated to independent product testing, investigative journalism, consumer-oriented research, public education, and consumer advocacy. Founded ...

also reported unsafe levels of

arsenic Arsenic is a chemical element; it has Symbol (chemistry), symbol As and atomic number 33. It is a metalloid and one of the pnictogens, and therefore shares many properties with its group 15 neighbors phosphorus and antimony. Arsenic is not ...

cadmium Cadmium is a chemical element; it has chemical symbol, symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12 element, group 12, zinc and mercury (element), mercury. Like z ...

, lead and mercury in several protein powder products. The

Canadian Broadcasting Corporation The Canadian Broadcasting Corporation (), branded as CBC/Radio-Canada, is the Canadian Public broadcasting, public broadcaster for both radio and television. It is a Crown corporation that serves as the national public broadcaster, with its E ...

(CBC) reported that protein spiking, i.e., the addition of amino acids to manipulate protein content analysis, was common. Many of the companies involved challenged CBC's claim. In some botanical products, undeclared ingredients were used to increase the bulk of the product and reduce its cost of manufacturing, while potentially violating certain religious and/or cultural limitations on consuming animal ingredients, such as cow, buffalo or deer. In 2015, the

New York Attorney General The attorney general of New York is the chief legal officer of the U.S. state of New York and head of the Department of Law of the state government. The office has existed in various forms since 1626, originally established under the Dutch c ...

(NY-AG) identified four major retailers with dietary supplement products that contained fraudulent and potentially dangerous ingredients, requiring the companies to remove the products from retail stores. According to the NY-AG, only about 20% of the herbal supplements tested contained the plants claimed. The methodology used by the NY-AG was disputed. The test involves looking for

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

fragments from the plants named as the dietary supplement ingredients in the products. One scientist said that it was possible that the extraction process used to create the supplements removed or destroyed all DNA. This, however, would not explain the presence of DNA from plants such as rice or wheat, that were not listed as ingredients. A study of dietary supplements sold between 2007 and 2016 identified 776 that contained unlisted

pharmaceutical drug Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy ( pharmacotherapy) is an important part of the ...

s, many of which could interact with other medications and lead to hospitalization. 86% of the adulterated supplements were marketed for weight loss and sexual performance, with many containing prescription

erectile dysfunction Erectile dysfunction (ED), also referred to as impotence, is a form of sexual dysfunction in males characterized by the persistent or recurring inability to achieve or maintain a Human penis, penile erection with sufficient rigidity and durat ...

medication. Muscle building supplements were contaminated with

anabolic steroid Anabolic steroids, also known as anabolic-androgenic steroids (AAS), are a class of drugs that are structurally related to testosterone, the main male sex hormone, and produce effects by binding to the androgen receptor (AR). Anabolism, Anaboli ...

s that can lead to health complications affecting the kidney, the heart, and cause

gynecomastia Gynecomastia (also spelled gynaecomastia) is the non-cancerous enlargement of one or both breasts in men due to the growth of breast tissue as a result of a hormone imbalance between estrogens and androgens. Updated by Brent Wisse (10 Novemb ...

. Multiple bodybuilding products also contained

antidepressant Antidepressants are a class of medications used to treat major depressive disorder, anxiety disorders, chronic pain, and addiction. Common side effects of antidepressants include Xerostomia, dry mouth, weight gain, dizziness, headaches, akathi ...

s and

antihistamine Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provides ...

s. Despite these findings, fewer than half of the adulterated supplements were recalled.

Regulatory compliance

The

has published harmonized rules on supplement products to assure consumers have minimal health risks from using dietary supplements and are not misled by advertising. In the United States and Canada, dietary supplements are considered a subset of foods, and are regulated accordingly. The U.S. Food and Drug Administration (FDA) monitors supplement products for accuracy in advertising and labeling. Dietary supplements are regulated by the FDA as

food product Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin and contains essential nutrients such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is inges ...

s subject to compliance with current

Good Manufacturing Practice Current good manufacturing practices (cGMP) are those conforming to the guidelines recommended by relevant agencies. Those agencies control the authorization and licensing of the manufacture and sale of food and beverages, cosmetics, pharmaceutic ...

s (CGMP) and labeling with science-based ingredient descriptions and advertising. When finding CGMP or advertising violations,

FDA warning letter An FDA warning letter is an official message from the United States Food and Drug Administration (FDA) to a manufacturer or other organization that has violated some rule in a federally regulated activity. The FDA defines an FDA warning letter as: ...

s are used to notify manufacturers of impending enforcement action, including

search and seizure Search and seizure is a procedure used in many Civil law (legal system), civil law and common law legal systems by which police or other authorities and their agents, who, suspecting that a crime has been committed, commence a search of a person ...

injunction An injunction is an equitable remedy in the form of a special court order compelling a party to do or refrain from doing certain acts. It was developed by the English courts of equity but its origins go back to Roman law and the equitable rem ...

, and financial penalties. Examples between 2016 and 2018 of CGMP and advertising violations by dietary supplement manufacturers included several with illegal compositions or advertising of vitamins and minerals. The U.S.

Federal Trade Commission The Federal Trade Commission (FTC) is an independent agency of the United States government whose principal mission is the enforcement of civil (non-criminal) United States antitrust law, antitrust law and the promotion of consumer protection. It ...

, which litigates against deceptive advertising in marketed products, established a consumer center to assist reports of false health claims in product advertising for dietary supplements. In 2017, the FTC successfully sued nine manufacturers for deceptive advertising of dietary supplements.

Adverse effects

In the United States, manufacturers of dietary supplements are required to demonstrate safety of their products before approval is granted for commerce. Despite this caution, numerous adverse effects have been reported, including muscle cramps, hair loss, joint pain,

liver disease Liver disease, or hepatic disease, is any of many diseases of the liver. If long-lasting it is termed chronic liver disease. Although the diseases differ in detail, liver diseases often have features in common. Liver diseases File:Ground gla ...

, and

allergic reactions Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermatitis, alle ...

, with 29% of the adverse effects resulting in hospitalization, and 20% in serious injuries or illnesses. The potential for adverse effects also occurs when individuals consume more than the necessary daily amount of

s or minerals that are needed to maintain normal body processes and functions. The incidence of adverse effects reported to the

FDA The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...

were due to "combination products" that contain multiple ingredients, whereas dietary supplements containing a single vitamin, mineral, lipid product, and herbal product were less likely to cause adverse effects related to excess supplementation. Among general reasons for the possible harmful effects of dietary supplements are: a) absorption in a short time, b) manufacturing quality and contamination, and c) enhancing both positive and negative effects at the same time. The incidence of liver injury from herbal and dietary supplements is about 16–20% of all supplement products causing injury, with the occurrence growing globally over the early 21st century. The most common liver injuries from weight loss and bodybuilding supplements involve hepatocellular damage with resulting

jaundice Jaundice, also known as icterus, is a yellowish or, less frequently, greenish pigmentation of the skin and sclera due to high bilirubin levels. Jaundice in adults is typically a sign indicating the presence of underlying diseases involving ...

, and the most common supplement ingredients attributed to these injuries are green tea

catechin Catechin is a flavan-3-ol, a type of secondary metabolite providing antioxidant roles in plants. It belongs to the subgroup of polyphenols called flavonoids. The name of the catechin chemical family derives from ''catechu'', which is the tannic ...

s, and the herbal

, aegeline. Weight loss supplements have also had adverse psychiatric effects. Some dietary supplements may also have adverse interactions with prescription medications that may enhance side effects or decrease therapeutic effects of medications.

Society and culture

Public health

Work done by scientists in the early 20th century on identifying individual nutrients in food and developing ways to manufacture them raised hopes that optimal health could be achieved and diseases prevented by adding them to food and providing people with dietary supplements; while there were successes in preventing

vitamin deficiencies Vitamin deficiency is the condition of a long-term lack of a vitamin. When caused by not enough vitamin intake it is classified as a ''primary deficiency'', whereas when due to an underlying disorder such as malabsorption it is called a ''seconda ...

, and preventing conditions like

neural tube defects Neural tube defects (NTDs) are a group of birth defects in which an opening in the spine or cranium remains from early in human development. In the third week of pregnancy called gastrulation, specialized cells on the dorsal side of the embry ...

by supplementation and

food fortification Food fortification is the addition of micronutrients (essential trace elements and vitamins) to food products. Food enrichment specifically means adding back nutrients lost during food processing, while fortification includes adding nutrients not ...

with

folic acid Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing and ...

, no targeted supplementation or fortification strategies to prevent major diseases like cancer or cardiovascular diseases have proved successful. For example, while increased consumption of fruits and vegetables are related to decreases in mortality, cardiovascular diseases and cancers, supplementation with key factors found in fruits and vegetable, like

antioxidants Antioxidants are Chemical compound, compounds that inhibit Redox, oxidation, a chemical reaction that can produce Radical (chemistry), free radicals. Autoxidation leads to degradation of organic compounds, including living matter. Antioxidants ...

, vitamins, or minerals, do not help and some have been found to be harmful in some cases. In general, as of 2016, robust clinical data is lacking, that shows that any kind of dietary supplementation does more good than harm for people who are healthy and eating a reasonable diet but there is clear data showing that dietary pattern and lifestyle choices are associated with health outcomes. As a result of the lack of good data for supplementation and the strong data for dietary pattern, public health recommendations for

healthy eating A healthy diet is a diet that maintains or improves overall health. A healthy diet provides the body with essential nutrition: fluid, macronutrients such as protein, micronutrients such as vitamins, and adequate fibre and food energy. A he ...

urge people to eat a

plant-based diet A plant-based diet is a diet consisting mostly or entirely of plant-based foods. It encompasses a wide range of dietary patterns that contain low amounts of animal products and high amounts of fiber-rich plant products such as vegetables ...

of whole foods, minimizing

ultra-processed food An ultra-processed food (UPF) is a grouping of processed food characterized by relatively involved methods of production. There is no simple definition of UPF, but they are generally understood to be an industrial creation derived from natural ...

, salt and sugar and to get exercise daily, and to abandon

Western pattern diet The Western pattern diet is a modern dietary pattern originating in the industrialized West which is generally characterized by high intakes of pre-packaged foods, refined grains, red and processed meat, high-sugar drinks, candy and swee ...

s and a sedentary lifestyle.

Legal regulation

United States

The regulation of food and dietary supplements by the U.S. Food and Drug Administration (FDA) is governed by various statutes enacted by the

United States Congress The United States Congress is the legislature, legislative branch of the federal government of the United States. It is a Bicameralism, bicameral legislature, including a Lower house, lower body, the United States House of Representatives, ...

. Pursuant to the

Federal Food, Drug, and Cosmetic Act The United States Federal Food, Drug, and Cosmetic Act (abbreviated as FFDCA, FDCA, or FD&C) is a set of laws passed by the United States Congress in 1938 giving authority to the U.S. Food and Drug Administration (FDA) to oversee the food safety ...

and accompanying legislation, the FDA has authority to oversee the quality of substances sold as food in the United States, and to monitor claims made in the labeling about both the composition and the health benefits of foods. Substances which the FDA regulates as food are subdivided into various categories, including foods,

food additive Food additives are substances added to food to preserve flavor or enhance taste, appearance, or other sensory qualities. Some additives, such as vinegar ( pickling), salt ( salting), smoke ( smoking) and sugar ( crystallization), have been used f ...

s, added substances (man-made substances which are not intentionally introduced into food, but nevertheless end up in it), and dietary supplements. The specific standards which the FDA exercises differ from one category to the next. Furthermore, the FDA has been granted a variety of means by which it can address violations of the standards for a given category of substances. Dietary supplement manufacture is required to comply with the good manufacturing practices established in 2007. The FDA can visit manufacturing facilities, send Warning Letters if not in compliance with GMPs, stop production, and if there is a health risk, require that the company conduct a recall. Only after a dietary supplement product is marketed, may the FDA's Center for Food Safety and Applied Nutrition (CFSAN) review the products for safety and effectiveness.

European Union

The European Union's (EU) Food Supplements Directive of 2002 requires that supplements be demonstrated to be safe, both in dosages and in purity. Only those supplements that have been proven to be safe may be sold in the EU without prescription. As a category of food, food supplements cannot be labeled with drug claims but can bear

health claim A health claim on a food label and in food marketing is a claim by a manufacturer of food products that their food will reduce the risk of developing a disease or condition. For example, it is claimed by the manufacturers of oat cereals that oa ...

s and nutrition claims. The dietary supplements industry in the United Kingdom (UK), one of the 28 countries in the bloc, strongly opposed the Directive. In addition, a large number of consumers throughout Europe, including over one million in the UK, and various doctors and scientists, had signed petitions by 2005 against what are viewed by the petitioners as unjustified restrictions of

consumer choice The theory of consumer choice is the branch of microeconomics that relates preferences to consumption expenditures and to consumer demand curves. It analyzes how consumers maximize the desirability of their consumption (as measured by their pr ...

. In 2004, along with two British trade associations, the

Alliance for Natural Health The Alliance for Natural Health (ANH) is an advocacy group founded in 2002 by Robert Verkerk and based in the United Kingdom. ANH was founded to raise funds to finance a legal challenge of the EU Food Supplement Directive. ANH lobbies against r ...

(ANH) had a legal challenge to the Food Supplements Directive referred to the

European Court of Justice The European Court of Justice (ECJ), officially the Court of Justice (), is the supreme court of the European Union in matters of European Union law. As a part of the Court of Justice of the European Union, it is tasked with interpreting ...

by the High Court in London. Although the European Court of Justice's Advocate General subsequently said that the bloc's plan to tighten rules on the sale of

and food supplements should be scrapped, he was eventually overruled by the European Court, which decided that the measures in question were necessary and appropriate for the purpose of protecting

public health Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals". Analyzing the de ...

. ANH, however, interpreted the ban as applying only to synthetically produced supplements, and not to vitamins and minerals normally found in or consumed as part of the diet. Nevertheless, the European judges acknowledged the Advocate General's concerns, stating that there must be clear procedures to allow substances to be added to the permitted list based on scientific evidence. They also said that any refusal to add the product to the list must be open to challenge in the courts.

Fraudulent products during the COVID-19 outbreak

During the

COVID-19 pandemic The COVID-19 pandemic (also known as the coronavirus pandemic and COVID pandemic), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), began with an disease outbreak, outbreak of COVID-19 in Wuhan, China, in December ...

in the United States, the

and

(FTC) warned consumers about marketing scams of fraudulent supplement products, including homeopathic remedies, cannabidiol products, teas,

essential oil An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the ...

tincture A tincture is typically an extract of plant or animal material dissolved in ethanol (ethyl alcohol). Solvent concentrations of 25–60% are common, but may run as high as 90%.Groot Handboek Geneeskrachtige Planten by Geert Verhelst In chemistr ...

s and

colloidal silver The medical uses of silver include its use in wound dressings, creams, and as an antibiotic coating on medical devices. Wound dressings containing silver sulfadiazine or silver nanomaterials may be used to treat external infections. The limited ...

, among others. By August 2020, the FDA and FTC had issued warning letters to dozens of companies advertising scam products, which were purported "to be drugs, medical devices or vaccines. Products that claim to cure, mitigate, treat, diagnose or prevent disease, but are not proven safe and effective for those purposes, defraud consumers of money and can place consumers at risk for serious harm"

Research

Examples of ongoing government research organizations to better understand the potential health properties and safety of dietary supplements are the

, the Office of Dietary Supplements of the United States

, the Natural and Non-prescription Health Products Directorate of Canada, and the

Therapeutic Goods Administration The Therapeutic Goods Administration (TGA) is the medicine and therapeutic regulatory agency of the Australian Government. As part of the Department of Health, Disability and Ageing, the TGA regulates the safety, quality, efficacy and advertisi ...

of Australia. Together with public and private research groups, these agencies construct

database In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and a ...

s on supplement properties, perform research on quality, safety, and population trends of supplement use, and evaluate the potential clinical efficacy of supplements for maintaining health or lowering disease risk.

Databases

As continual research on the properties of supplements accumulates, databases or fact sheets for various supplements are updated regularly, including the Dietary Supplement Label Database, Dietary Supplement Ingredient Database, and Dietary Supplement Facts Sheets of the United States. In Canada where a license is issued when a supplement product has been proven by the manufacturer and government to be safe, effective and of sufficient quality for its recommended use, an eight-digit Natural Product Number is assigned and recorded in a Licensed Natural Health Products Database. The European Food Safety Authority maintains a

compendium A compendium ( compendia or compendiums) is a comprehensive collection of information and analysis pertaining to a body of knowledge. A compendium may concisely summarize a larger work. In most cases, the body of knowledge will concern a specific ...

of botanical ingredients used in manufacturing of dietary supplements. In 2015, the Australian Government's Department of Health published the results of a review of herbal supplements to determine if any were suitable for coverage by

health insurance Health insurance or medical insurance (also known as medical aid in South Africa) is a type of insurance that covers the whole or a part of the risk of a person incurring medical expenses. As with other types of insurance, risk is shared among ma ...

. Establishing guidelines to assess safety and efficacy of botanical supplement products, the

European Medicines Agency The European Medicines Agency (EMA) is an agency of the European Union (EU) in charge of the evaluation and supervision of pharmaceutical products. Prior to 2004, it was known as the European Agency for the Evaluation of Medicinal Products ...

provided criteria for evaluating and grading the quality of clinical research in preparing monographs about herbal supplements. In the United States, the

National Center for Complementary and Integrative Health The National Center for Complementary and Integrative Health (NCCIH) is a United States government agency which explores complementary and alternative medicine (CAM). It was created in 1991 as the Office of Alternative Medicine (OAM), and r ...

of the National Institutes of Health provides fact sheets evaluating the safety, potential effectiveness and side effects of many botanical products.

Quality and safety

To assure supplements have sufficient quality, standardization, and safety for public consumption, research efforts have focused on development of reference materials for supplement manufacturing and monitoring. High-dose products have received research attention, especially for emergency situations such as

vitamin A Vitamin A is a fat-soluble vitamin that is an essential nutrient. The term "vitamin A" encompasses a group of chemically related organic compounds that includes retinol, retinyl esters, and several provitamin (precursor) carotenoids, most not ...

deficiency in malnutrition of children, and for women taking folate supplements to reduce the risk of breast cancer.

Population monitoring

In the United States, the

National Health and Nutrition Examination Survey The National Health and Nutrition Examination Survey (NHANES) is a survey research program conducted by the National Center for Health Statistics (NCHS) to assess the health and nutritional status of adults and children in the United States, and ...

(NHANES) has investigated habits of using dietary supplements in context of total nutrient intakes from the diet in adults and children. Over the period of 1999 to 2012, use of multivitamins decreased, and there was wide variability in the use of individual supplements among subgroups by age, sex, race/ethnicity, and educational status. Particular attention has been given to use of folate supplements by young women to reduce the risk of

fetal A fetus or foetus (; : fetuses, foetuses, rarely feti or foeti) is the unborn offspring of a viviparous animal that develops from an embryo. Following the embryonic stage, the fetal stage of development takes place. Prenatal development is a ...

Clinical studies

Limited human research has been conducted on the potential for dietary supplementation to affect disease risk. Examples: *

vitamin D Vitamin D is a group of structurally related, fat-soluble compounds responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, along with numerous other biological functions. In humans, the most important compo ...

acute

respiratory tract infection Respiratory tract infections (RTIs) are infectious diseases involving the lower or upper respiratory tract. An infection of this type usually is further classified as an upper respiratory tract infection (URI or URTI) or a lower respiratory tract ...

s *

maternal

and adverse effects on the

* multiple supplements no evidence of benefit to lower risk of death, cardiovascular diseases or cancer * magnesium supplementation in reducing all-cause and cancer mortality, as well as improving glucose parameters in people with diabetes and insulin-sensitivity parameters in those at high risk of diabetes. *

alone or with B vitamins stroke A 2017 academic review indicated a rising incidence of liver injury from use of herbal and dietary supplements, particularly those with

steroid A steroid is an organic compound with four fused compound, fused rings (designated A, B, C, and D) arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes t ...

green tea extract Green tea is a type of tea made from the leaves and buds of the ''Camellia sinensis'' that have not undergone the Tea processing#General, withering and oxidation process that creates oolong teas and black teas. Green tea originated in China in t ...

, or multiple ingredients.

Absence of benefit

The potential benefit of using essential nutrient dietary supplements to lower the risk of diseases has been refuted by findings of no effect or weak evidence in numerous clinical reviews, such as for HIV, or

tuberculosis Tuberculosis (TB), also known colloquially as the "white death", or historically as consumption, is a contagious disease usually caused by ''Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can al ...

Reporting bias

A review of clinical trials registered at

clinicaltrials.gov ClinicalTrials.gov is a clinical trials registry, registry of clinical trials. It is run by the United States National Library of Medicine (NLM) at the National Institutes of Health, and holds registrations from over 444,000 trials from 221 cou ...

, which would include both drugs and supplements, reported that nearly half of completed trials were sponsored wholly or partially by industry. This does not automatically imply bias, but there is evidence that because of selective non-reporting, results in support of a potential drug or supplement ingredient are more likely to be published than results that do not demonstrate a statistically significant benefit. One review reported that fewer than half of the registered clinical trials resulted in publication in peer-reviewed journals.

Future

Improving public information about use of dietary supplements involves investments in professional training programs, further studies of population and nutrient needs, expanding the

information, enhancing collaborations between governments and universities, and translating dietary supplement research into useful information for consumers,

health professional A health professional, healthcare professional (HCP), or healthcare worker (sometimes abbreviated as HCW) is a provider of health care treatment and advice based on formal training and experience. The field includes those who work as a Nursing, nur ...

s, scientists, and policymakers. Future demonstration of efficacy from use of dietary supplements requires high-quality

clinical research Clinical research is a branch of medical research that involves people and aims to determine the effectiveness (efficacy) and safety of medications, devices, diagnostic products, and treatment regimens intended for improving human health. The ...

using rigorously qualified products and compliance with established guidelines for reporting of clinical trial results (e.g., CONSORT guidelines).

References

External links

* * {{DEFAULTSORT:Dietary Supplement Articles containing video clips

Definition

Types

Vitamins

Minerals

Proteins and amino acids

Bodybuilding supplements

Beauty supplements

Essential fatty acids

Natural products

Probiotics

Fertility

Prenatal

Pharmacotherapy

Industry

Adulteration, contamination and mislabeling

Regulatory compliance

Adverse effects

Society and culture

Public health

Legal regulation

United States

European Union

Fraudulent products during the COVID-19 outbreak

Research

Databases

Quality and safety

Population monitoring

Clinical studies

Absence of benefit

Reporting bias

Future

See also

References

Further reading

External links