There are a total of 47 Vitamins that have been compiled and organized in this comprehensive list. The selection includes only recognized vitamins — vitamin A; the eight B vitamins listed individually; vitamin C; vitamin D (D2 and D3); vitamin E; and vitamin K (K1 and K2).

Vitamins are essential micronutrients the body needs in small amounts for normal growth, metabolism, and repair. They include fat‑soluble and water‑soluble types with different roles and storage patterns. Deficiencies or excesses can cause distinct clinical problems and affect long‑term health. Many vitamins come from food; some are produced by gut microbes or require supplementation in specific populations.

Interesting and little-known facts about Vitamins:
– About 1,000,000,000 people worldwide have vitamin D deficiency or insufficiency, making it one of the most common global nutrient gaps.
– The B complex comprises eight distinct vitamins (B1, B2, B3, B5, B6, B7, B9, B12), each with unique biochemical roles.
– Only about 10 mg of vitamin C per day prevents scurvy in adults, showing how small amounts can avert serious disease.
– Preformed vitamin A (retinol) is teratogenic at high doses, so upper limits matter especially during pregnancy.
– The body can synthesize niacin (vitamin B3) from the amino acid tryptophan when dietary niacin is low.

The alphabetical index links to concise entries for each vitamin and its common variants.
Each entry has a brief benefit summary (1–2 sentences).
It lists 3–5 primary food sources.
It gives the RDI with units, any age/gender caveats, and the authoritative source (NIH, EFSA, WHO, or USDA).