Pyridoxine (PN) is a form of vitamin B₆ found commonly in food and used as a

dietary supplement A dietary supplement is a manufactured product intended to supplement a person's diet by taking a pill (pharmacy), pill, capsule (pharmacy), capsule, tablet (pharmacy), tablet, powder, or liquid. A supplement can provide nutrients eithe ...

. As a supplement it is used to treat and prevent

pyridoxine deficiency Vitamin B6 is one of the B vitamins, and is an essential nutrient for humans. The term essential nutrient refers to a group of six chemically similar compounds, i.e., "vitamers", which can be interconverted in biological systems. Its active f ...

, sideroblastic anaemia,

pyridoxine-dependent epilepsy Pyridoxine-dependent epilepsy (PDE) is a rare genetic disorder characterized by intractable seizures in the prenatal and neonatal period. The disorder was first recognized in the 1950s, with the first description provided by Hunt et al. in 1954. ...

, certain

metabolic disorders A metabolic disorder is a disorder that negatively alters the body's processing and distribution of macronutrients, such as proteins, fats, and carbohydrates. Metabolic disorders can happen when abnormal chemical reactions in the body alter the ...

, side effects or complications of

isoniazid Isoniazid, also known as isonicotinic acid hydrazide (INH), is an antibiotic used for the treatment of tuberculosis. For active tuberculosis, it is often used together with rifampicin, pyrazinamide, and either streptomycin or ethambutol. F ...

use, and certain types of

mushroom poisoning Mushroom poisoning is poisoning resulting from the ingestion of mushrooms that contain toxicity, toxic substances. Signs and symptoms, Symptoms can vary from slight Gastrointestinal tract, gastrointestinal discomfort to death in about 10 days. Mus ...

. It is used by mouth or by injection. It is usually well tolerated. Occasionally side effects include headache, numbness, and sleepiness. Normal doses are safe during

pregnancy Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Conception (biology), Conception usually occurs ...

and

breastfeeding Breastfeeding, also known as nursing, is the process where breast milk is fed to a child. Infants may suck the milk directly from the breast, or milk may be extracted with a Breast pump, pump and then fed to the infant. The World Health Orga ...

. Pyridoxine is in the

vitamin B B vitamins are a class of water-soluble vitamins that play important roles in cell metabolism and synthesis of red blood cells. They are a chemically diverse class of compounds. Dietary supplements containing all eight are referred to as a vita ...

family of vitamins. It is required by the body to metabolise

amino acids 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 Proteinogenic amino acid, 22 α-amino acids incorporated into p ...

carbohydrates A carbohydrate () is a biomolecule composed of carbon (C), hydrogen (H), and oxygen (O) atoms. The typical hydrogen-to-oxygen atomic ratio is 2:1, analogous to that of water, and is represented by the empirical formula (where ''m'' and ''n'' ma ...

, and

lipids Lipids are a broad group of organic compounds which include fats, waxes, sterols, fat-soluble vitamins (such as vitamins Vitamin A, A, Vitamin D, D, Vitamin E, E and Vitamin K, K), monoglycerides, diglycerides, phospholipids, and others. The fu ...

. Sources in the diet include

meat Meat is animal Tissue (biology), tissue, often muscle, that is eaten as food. Humans have hunted and farmed other animals for meat since prehistory. The Neolithic Revolution allowed the domestication of vertebrates, including chickens, sheep, ...

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

vegetables Vegetables are edible parts of plants that are consumed by humans or other animals as food. This original meaning is still commonly used, and is applied to plants collectively to refer to all edible plant matter, including flowers, fruits, ...

, and

grain A grain is a small, hard, dry fruit (caryopsis) – with or without an attached husk, hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and ...

Medical uses

As a treatment (oral or injection), it is used to treat or prevent

, sideroblastic anaemia,

, certain

, side effects of

treatment and certain types of

. Isoniazid is an

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 ...

used for the treatment of

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 ...

. Common side effect include numbness in the hands and feet. Co-treatment with vitamin B₆ alleviates the numbness. Pyridoxine-dependent epilepsy is a type of rare infant epilepsy that does not improve with typical anti-seizure medications. Pyridoxine in combination with

doxylamine Doxylamine is an antihistamine medication used to treat insomnia and allergies, and—in combination with pyridoxine ( vitamin B6)—to treat morning sickness in pregnant women. It is available over-the-counter and is sold under such brand names ...

is used as a treatment for

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 ...

in pregnant women.

Side effects

It is usually well tolerated, though overdose toxicity is possible. Occasionally side effects include headache, numbness, and sleepiness. Pyridoxine overdose can cause a

peripheral sensory neuropathy Peripheral neuropathy, often shortened to neuropathy, refers to damage or disease affecting the nerves. Damage to nerves may impair sensation, movement, gland function, and/or organ function depending on which nerve fibers are affected. Neuropa ...

characterized by poor coordination, numbness, and decreased sensation to touch, temperature, and vibration. Healthy human blood levels of pyridoxine are 2.1–21.7 ng/mL. Normal doses are safe during

and

Mechanism

Pyridoxine is in the

family of vitamins. It is required by the body to make

, and

. Sources in the diet include

, and

. It is also required for muscle phosphorylase activity associated with glycogen metabolism.

Metabolism

The half-life of pyridoxine varies according to different sources: one source suggests that the half-life of ''pyridoxine'' is up to 20 days, while another source indicates half-life of ''vitamin B₆'' is in range of 25 to 33 days. After considering the different sources, it can be concluded that the half-life of pyridoxine is typically measured in several weeks.

History

Pyridoxine was discovered in 1934, isolated in 1938, and first made in 1939. It is on the

World Health Organization's List of Essential Medicines The WHO Model List of Essential Medicines (aka Essential Medicines List or EML), published by the World Health Organization (WHO), contains the medications considered to be most effective and safe to meet the most important needs in a health s ...

. Pyridoxine is available both as a

generic medication A generic drug is a pharmaceutical drug that contains the same chemical substance as a drug that was originally protected by chemical patents. Generic drugs are allowed for sale after the patents on the original drugs expire. Because the active ch ...

and

over the counter Over-the-counter (OTC) drugs are medicines sold directly to a consumer without a requirement for a prescription from a healthcare professional, as opposed to prescription drugs, which may be supplied only to consumers possessing a valid pres ...

product. Foods, such as

breakfast cereal Breakfast cereal is a category of food, including food products, made from food processing, processed cereal, cereal grains, that are eaten as part of breakfast or as a snack food, primarily in Western societies. Although warm, cooked cereals li ...

have pyridoxine added in some countries.

References

External links

* * * {{Authority control B vitamins Hydroxypyridines World Health Organization essential medicines Wikipedia medicine articles ready to translate Cofactors Primary alcohols Triols pt:Piridoxina