Vegetarian nutrition is the set of health-related challenges and advantages of

vegetarian Vegetarianism is the practice of abstaining from the consumption of meat (red meat, poultry, seafood, insects, and the flesh of any other animal). It may also include abstaining from eating all by-products of animal slaughter. Vegetariani ...

diets The Low Countries comprise the coastal Rhine–Meuse–Scheldt delta region in Western Europe, whose definition usually includes the modern countries of Luxembourg, Belgium and the Netherlands. Both Belgium and the Netherlands derived their ...

. Appropriately planned vegetarian diets are healthful and

nutrition Nutrition is the biochemical and physiological process by which an organism uses food to support its life. It provides organisms with nutrients, which can be metabolized to create energy and chemical structures. Failure to obtain sufficient ...

ally adequate for all stages of the human life cycle, including during pregnancy, lactation, infancy, childhood, and adolescence. However, vegetarian diets deficient in vitamin B₁₂ or calories may compromise children's health and development. The UK

National Health Service The National Health Service (NHS) is the umbrella term for the publicly funded healthcare systems of the United Kingdom (UK). Since 1948, they have been funded out of general taxation. There are three systems which are referred to using the " ...

recommends that vegetarian diets should also follow the general recommendations for healthy diets, such as low fat, salt and sugar intakes and 5 fruits or vegetables a day.

Qatar Qatar (, ; ar, قطر, Qaṭar ; local vernacular pronunciation: ), officially the State of Qatar,) is a country in Western Asia. It occupies the Qatar Peninsula on the northeastern coast of the Arabian Peninsula in the Middle East; it ...

's public health ministry states, "One cannot be a healthy vegetarian by going to a fast food restaurant and ordering french fries and soda!". Vegetarian diets tend to be rich in carbohydrates,

omega-6 fatty acids Omega-6 fatty acids (also referred to as ω-6 fatty acids or ''n''-6 fatty acids) are a family of polyunsaturated fatty acids that have in common a final carbon-carbon double bond in the ''n''-6 position, that is, the sixth bond, counting from ...

dietary fibre Dietary fiber (in British English fibre) or roughage is the portion of plant-derived food that cannot be completely broken down by human digestive enzymes. Dietary fibers are diverse in chemical composition, and can be grouped generally by th ...

carotenoids Carotenoids (), also called tetraterpenoids, are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, co ...

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 ...

vitamin C Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) ...

vitamin E Vitamin E is a group of eight fat soluble compounds that include four tocopherols and four tocotrienols. Vitamin E deficiency, which is rare and usually due to an underlying problem with digesting dietary fat rather than from a diet low in vi ...

potassium Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosph ...

and

magnesium Magnesium is a chemical element with the 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 of the periodic ta ...

. They are possibly low in saturated fat,

cholesterol Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell mem ...

, and animal protein.

Critical nutrients

Protein

Despite the long-standing, widespread belief that vegetarians must consume grains and beans within a short time to make a '' complete protein'' that contains all 9

essential amino acid An essential amino acid, or indispensable amino acid, is an amino acid that cannot be synthesized from scratch by the organism fast enough to supply its demand, and must therefore come from the diet. Of the 21 amino acids common to all life form ...

s that must be supplied through diet, this has never been substantiated by research. The protein-combining theory was brought to popular attention after being promoted in

Frances Moore Lappé Frances Moore Lappé (born February 10, 1944) is an American researcher and author in the area of food and democracy policy. She is the author of 19 books including the three-million-copy selling 1971 book '' Diet for a Small Planet'', which the ...

's 1971 bestselling book ''

Diet for a Small Planet ''Diet for a Small Planet'' is a 1971 bestselling book by Frances Moore Lappé, the first major book to note the environmental impact of meat production as wasteful and a contributor to global food scarcity. She argued for environmental vegeta ...

''. In later editions of the book, starting in 1981, Lappé withdrew her contention that ''protein combining'' is necessary. Plant foods rich in protein include

soy bean The soybean, soy bean, or soya bean (''Glycine max'') is a species of legume native to East Asia, widely grown for its edible bean, which has numerous uses. Traditional unfermented food uses of soybeans include soy milk, from which tofu a ...

s and soy products such as

tofu Tofu (), also known as bean curd in English, is a food prepared by coagulating soy milk and then pressing the resulting curds into solid white blocks of varying softness; it can be ''silken'', ''soft'', ''firm'', ''extra firm'' or ''super f ...

veggie burger A veggie burger is a hamburger patty that does not contain meat. It may be made from ingredients like beans, especially soybeans and tofu, nuts, grains, seeds or fungi such as mushrooms or mycoprotein. The patties that are the essence of a ve ...

s, and

soy milk Soy milk (simplified Chinese: 豆浆; traditional Chinese: 豆漿) also known as soya milk or soymilk, is a plant-based drink produced by soaking and grinding soybeans, boiling the mixture, and filtering out remaining particulates. It is a sta ...

; other legumes; nuts and

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

s; and cereal grains.

Vitamin B₁₂

Vitamin B₁₂ deficiency can be extremely serious and lead to

megaloblastic anemia Megaloblastic anemia is a type of macrocytic anemia. An anemia is a red blood cell defect that can lead to an undersupply of oxygen. Megaloblastic anemia results from inhibition of DNA synthesis during red blood cell production. When DNA synth ...

, nerve degeneration and irreversible neurological damage. Vegetarians may get vitamin B₁₂ from eggs and dairy products (milk, cheese, etc.); for some, this is adequate, while others may still remain B₁₂-deficient. More broadly, according to the

Academy of Nutrition and Dietetics The Academy of Nutrition and Dietetics is a 501(c)(6) trade association in the United States. With over 112,000 members, the association claims to be the largest organization of food and nutrition professionals. It has registered dietitian n ...

, even the form of vitamin B₁₂ sourced from animal products is protein-bound and not as easily digested as supplements, especially as people age, and therefore B₁₂ supplementation is recommended for everyone over the age of 50. Pregnant and lactating vegetarian mothersand breastfed infants if the vegetarian mother's diet is not supplementedshould also use supplements, whether B₁₂-pills, B₁₂-injections, or B₁₂-fortified foods, if they don't get adequate vitamin B₁₂ from animal products like eggs or dairy. Huehnereier 2989

Generally, humans need 2.4 to 3

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 whe ...

s of vitamin B₁₂ each day. There are cases to suggest that vegetarians and vegans who are not taking vitamin B₁₂ supplements or food fortified with B₁₂ do not consume sufficient servings of B₁₂ and have abnormally low blood concentrations of vitamin B₁₂. This is because, unless fortified, plant foods do not contain reliable amounts of active vitamin B₁₂. It is essential, therefore, that vegetarians consume adequate amounts of dietary supplements or foods that have been fortified with B₁₂, such as vegetable stock,

mixes,

textured vegetable protein Textured or texturized vegetable protein (TVP), also known as textured soy protein (TSP), soy meat, or soya chunks is a defatted soy flour product, a by-product of extracting soybean oil. It is often used as a meat analogue or meat extender ...

s, vegetable and sunflower margarines, and breakfast cereals.The Vegetarian Society.
Information Sheet: Vitamin B
''. Retrieved 26 April 2007. B₁₂ used in these foods or supplements is typically grown from vegan sources (such as

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...

). Soybeans and barley seeds from plants grown in soils amended either with cow dung (which is rich in B₁₂) or with pure B₁₂ had a higher B₁₂ content than those grown without this supplementation.

Omega-3 fatty acids

Vegetarian diets can be low in

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 chem ...

s (O3FAs). Major vegetarian O3FA sources include algae, hempseeds and hempseed oil,

walnut A walnut is the edible seed of a drupe of any tree of the genus ''Juglans'' (family Juglandaceae), particularly the Persian or English walnut, '' Juglans regia''. Although culinarily considered a "nut" and used as such, it is not a true ...

s, flaxseeds and flaxseed oil, olive oil,

canola oil Close-up of canola blooms Canola flower Rapeseed oil is one of the oldest known vegetable oils. There are both edible and industrial forms produced from rapeseed, the seed of several cultivars of the plant family Brassicaceae. Historically, ...

avocado The avocado (''Persea americana'') is a medium-sized, evergreen tree in the laurel family ( Lauraceae). It is native to the Americas and was first domesticated by Mesoamerican tribes more than 5,000 years ago. Then as now it was prized for ...

, and chia seeds. A potential problem is that vegetarian diets lacking eggs or generous amounts of

edible seaweed Edible seaweed, or sea vegetables, are seaweeds that can be eaten and used for culinary purposes. They typically contain high amounts of fiber. They may belong to one of several groups of multicellular algae: the red algae, green algae, and brown ...

generally lack a direct source of long-chain O3FAs such as

docosahexaenoic acid Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is a primary structural component of the human brain, cerebral cortex, skin, and retina. In physiological literature, it is given the name 22:6(n-3). It can be synthesized from alpha-lin ...

(DHA) and

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 with a 20-c ...

(EPA). Vegetarian diets may also have a high ratio of

to O3FAs, which inhibits the conversion of short-chain fatty acids such as

alpha-Linolenic acid ''alpha''-Linolenic acid (ALA), also known as α-Linolenic acid (from Greek ''alpha'' meaning "first" and ''linon'' meaning flax), is an ''n''−3, or omega-3, essential fatty acid. ALA is found in many seeds and oils, including flaxseed, wa ...

(ALA), which is found in most vegetarian O3FA sources, to EPA and DHA. Short-term supplemental ALA has been shown to increase EPA levels but not DHA levels, suggesting poor conversion of the intermediary EPA to DHA. To remedy this, DHA and EPA supplements derived from microalgae are available. A 2022 review found that microalgal oil supplementation is consistent in increasing DHA and EPA levels, whilst high dose

flaxseed Flax, also known as common flax or linseed, is a flowering plant, ''Linum usitatissimum'', in the family Linaceae. It is cultivated as a food and fiber crop in regions of the world with temperate climates. Textiles made from flax are known in ...

or echium seed oil supplements provide no increase despite significant increases in ALA levels.

Calcium

In general, lacto-ovo-vegetarians have a relatively high intake of

calcium Calcium is a chemical element with the 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 t ...

that meet or exceed calcium recommendations. A 2022 review found no significant difference in calcium intake between vegetarians and omnivores. Vegetarians can obtain calcium from dairy products, calcium-fortified plant milks, almonds, figs, oranges, calcium-set tofu as well as low-oxalate vegetables such as bok choy, kale and turnip greens. Compared with omnivores, vegetarians tend to have a lower bone mineral density (BMD) but not a higher fracture rate.

Iron

Vegetarians are more likely to have lower iron stores compared with non-vegetarians and have a higher risk of iron deficiency anemia. Lacto-ovo-vegetarians that overly rely on dairy consumption may lead to an elevated calcium intake which can affect iron absorption. The recommended iron intake for vegetarians is 180% that of nonvegetarians due to the bioavailability of non-heme iron. Although a lower ''percentage'' of non-heme iron is absorbed by the body, greater total ''amounts'' of non-heme iron are concentrated in many non-meat sources of iron, and therefore breakfast cereals, eggs, nuts, seeds, and legumes (including soy foods, peas, beans, chickpeas, and

lentils The lentil (''Lens culinaris'' or ''Lens esculenta'') is an edible legume. It is an annual plant known for its lens-shaped seeds. It is about tall, and the seeds grow in pods, usually with two seeds in each. As a food crop, the largest produ ...

) are significant sources of iron, and a well-planned vegetarian diet should not lead to iron deficiency. Non-heme iron is more sensitive to both ''inhibitors'' and ''enhancers'' of iron absorption:

Vitamin C Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) ...

is an iron absorption enhancer; the main inhibitors for most people are phytates (e.g. legumes and cereal grains), but other inhibitors include

tannins Tannins (or tannoids) are a class of astringent, polyphenolic biomolecules that bind to and precipitate proteins and various other organic compounds including amino acids and alkaloids. The term ''tannin'' (from Anglo-Norman ''tanner'', f ...

(from

tea Tea is an aromatic beverage prepared by pouring hot or boiling water over cured or fresh leaves of ''Camellia sinensis'', an evergreen shrub native to East Asia which probably originated in the borderlands of southwestern China and north ...

and

wine Wine is an alcoholic drink typically made from fermented grapes. Yeast consumes the sugar in the grapes and converts it to ethanol and carbon dioxide, releasing heat in the process. Different varieties of grapes and strains of yeasts are m ...

, and

polyphenol Polyphenols () are a large family of naturally occurring organic compounds characterized by multiples of phenol units. They are abundant in plants and structurally diverse. Polyphenols include flavonoids, tannic acid, and ellagitannin, some o ...

Iron Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...

is an integral part in the chemical structure of many

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

s and

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

s, which maintain good health. In humans, iron is an essential component of proteins involved in the transport of

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as ...

red blood cell Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...

s. Iron also helps regulate cell growth and cellular differentiation.

Zinc

A 2013 review found that zinc intake and serum zinc concentrations were significantly lower in populations that follow vegetarian diets compared with non-vegetarians.

Phytate Phytic acid is a six-fold dihydrogenphosphate ester of inositol (specifically, of the ''myo'' isomer), also called inositol hexakisphosphate (IP6) or inositol polyphosphate. At physiological pH, the phosphates are partially ionized, resulting in ...

s in many

whole grain A whole grain is a grain of any cereal and pseudocereal that contains the endosperm, germ, and bran, in contrast to refined grains, which retain only the endosperm. As part of a general healthy diet, consumption of whole grains is associated ...

s, and dietary fiber in many plant foods may interfere with zinc absorption, and marginal zinc intake has poorly understood effects. Vegetarians may need more than the US Recommended Daily Allowance of 15 mg of zinc each day to compensate if their diet is high in phytates. Major plant sources of

zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc 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 periodi ...

include cooked dried beans,

, fortified breakfast cereals, soy products, nuts, peas, and seeds.

Iodine

One study reported a "potential danger of odine(I) deficiency disorders due to strict forms of vegetarian nutrition, especially when fruits and vegetables grown in soils with low odinelevels are ingested." Iodine, however, is usually supplied by

iodized salt Iodised salt ( also spelled iodized salt) is table salt mixed with a minute amount of various salts of the element iodine. The ingestion of iodine prevents iodine deficiency. Worldwide, iodine deficiency affects about two billion people and is t ...

and other sources in

first world countries The concept of First World originated during the Cold War and comprised countries that were under the influence of the United States and the rest of NATO and opposed the Soviet Union and/or communism during the Cold War. Since the collapse of ...

. Other significant vegetarian sources of iodine include

and bread made with

dough conditioner A dough conditioner, flour treatment agent, improving agent or bread improver is any ingredient or chemical added to bread dough to strengthen its texture or otherwise improve it in some way. Dough conditioners may include enzymes, yeast nutrients ...

Health effects

Evidence suggests that vegetarian diets have beneficial effects on

blood lipids Blood lipids (or blood fats) are lipids in the blood, either free or bound to other molecules. They are mostly transported in a protein capsule, and the density of the lipids and type of protein determines the fate of the particle and its influence ...

and that vegetarians have a reduced risk of

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

, cardiovascular disease, hypertension and

type 2 diabetes Type 2 diabetes, formerly known as adult-onset diabetes, is a form of diabetes mellitus that is characterized by high blood sugar, insulin resistance, and relative lack of insulin. Common symptoms include increased thirst, frequent urinatio ...

References

External links

* United States Department of Agriculture
Vegetarian Nutriton
* Mayo Clinic
Vegetarian diet: How to get the best nutrition
* Medline Plus

{{Vegetarianism Vegetarianism Nutrition by type