A vitamin is a small organic molecule required in small amounts by an individual. In humans, a molecule is defined as a vitamin when it cannot be made in sufficient quantities by us, and thus must be obtained from the diet. Until the early1900s, vitamins were obtained solely through food intake. As the scientific understanding of vitamins increased, it was recognized that dietary habits and the seasonal availability of food could significantly alter the types and amounts of vitamins ingested. To provide a constant and continued source of vitamins, inexpensive pills containing synthesized vitamins were developed allowing for supplementation of the dietary intake.
> Function of Vitamins
> The 13 Essential Vitamins
> In Nutrition & Disease