**Historical Context of Vitamins:**
– Ancient Egyptians used liver for treating night blindness.
– Discovery of vitamin deficiency diseases among ship crews during the Age of Discovery.
– James Lind’s discovery linking citrus foods to scurvy prevention.
– Robert Falcon Scott’s Antarctic expeditions linking scurvy to tainted canned food.
– Umetaro Suzuki isolating the first vitamin complex in 1910.
– Frederick Hopkins proposing accessory factors in foods essential for human functions.
**Biochemical Functions and Deficiency Diseases:**
– Vitamin A regulates cell and tissue growth.
– Vitamin D regulates mineral metabolism for bones.
– B complex vitamins function as enzyme cofactors.
– Vitamins C and E act as antioxidants.
– Beriberi endemic in East Asia due to polished white rice consumption.
– Vitamin C deficiency leading to scurvy in sailors.
– Common vitamin B deficiency diseases in history.
**Commercialization and Nobel Prizes in Vitamin Research:**
– Vitamins essential for proper metabolic function.
– Vitamin supplements becoming commercially available in the 1950s.
– Nobel Prizes awarded for significant contributions to vitamin research.
– History of promotional marketing for vitamins in magazines.
– Etymology of the term ‘vitamin’ and its classification into water-soluble and fat-soluble categories.
**Intake, Deficiencies, and Excess Intake of Vitamins:**
– Vitamins obtained through diet or synthesized by the body.
– Primary and secondary deficiencies leading to conditions like beriberi, pellagra, and rickets.
– Excess intake of certain vitamins can be toxic and may lead to overdose.
– Effects of cooking on vitamin bioavailability and intake guidelines.
– Importance of supplementation and regulations regarding safe dosages in Europe.
**Governmental Regulation and Miscellaneous Information:**
– Categorization of dietary supplements as food in most countries.
– Regulations for supplement safety and efficacy varying widely by country.
– Naming conventions for vitamins and their historical changes.
– Exploration of specific vitamins like E, A, and D in various contexts.
– References for further reading and related topics like vitamin deficiency and human nutrition.
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 sufficient quantities for survival, and therefore must be obtained through the diet. For example, vitamin C can be synthesized by some species but not by others; it is not considered a vitamin in the first instance but is in the second. Most vitamins are not single molecules, but groups of related molecules called vitamers. For example, there are eight vitamers of vitamin E: four tocopherols and four tocotrienols.
| Vitamin | |
|---|---|
| Drug class | |
 A bottle of B-complex vitamin pills | |
| Pronunciation | UK: /ˈvɪtəmɪn, ˈvaɪt-/ VIT-ə-min, VYTE-, US: /ˈvaɪtəmɪn/ VY-tə-min |
| Legal status | |
| In Wikidata | |
The term vitamin does not include the three other groups of essential nutrients: minerals, essential fatty acids, and essential amino acids.
Major health organizations list thirteen vitamins:
- Vitamin A (all-trans-retinols, all-trans-retinyl-esters, as well as all-trans-beta-carotene and other provitamin A carotenoids)
- Vitamin B1 (thiamine)
- Vitamin B2 (riboflavin)
- Vitamin B3 (niacin)
- Vitamin B5 (pantothenic acid)
- Vitamin B6 (pyridoxine)
- Vitamin B7 (biotin)
- Vitamin B9 (folic acid and folates)
- Vitamin B12 (cobalamins)
- Vitamin C (ascorbic acid and ascorbates)
- Vitamin D (calciferols)
- Vitamin E (tocopherols and tocotrienols)
- Vitamin K (phylloquinones, menaquinones, and menadiones)
Some sources include a fourteenth, choline.
Vitamins have diverse biochemical functions. Vitamin A acts as a regulator of cell and tissue growth and differentiation. Vitamin D provides a hormone-like function, regulating mineral metabolism for bones and other organs. The B complex vitamins function as enzyme cofactors (coenzymes) or the precursors for them. Vitamins C and E function as antioxidants. Both deficient and excess intake of a vitamin can potentially cause clinically significant illness, although excess intake of water-soluble vitamins is less likely to do so.
All the vitamins were discovered between 1913 and 1948. Historically, when intake of vitamins from diet was lacking, the results were vitamin deficiency diseases. Then, starting in 1935, commercially produced tablets of yeast-extract vitamin B complex and semi-synthetic vitamin C became available. This was followed in the 1950s by the mass production and marketing of vitamin supplements, including multivitamins, to prevent vitamin deficiencies in the general population. Governments have mandated the addition of some vitamins to staple foods such as flour or milk, referred to as food fortification, to prevent deficiencies. Recommendations for folic acid supplementation during pregnancy reduced risk of infant neural tube defects.