From ArticleWorld

A vitamin is defined as an organic molecule that a living organism finds necessary to maintain its proper health. When an organism is deprived of all sources of a vitamin it will often suffer health effects, known as a deficiency.



The word was coined by Casimir Funk, a Polish biochemist, in 1912, although the value of consuming certain foods in order to maintain one's health was recognized long before that. There is evidence that the Egyptians used liver to cure night blindness (now known to be a vitamin A deficiency).


Typically, organisms must be consumed, or obtained from a source outside of the body, since the body cannot produce them. The most common way to do this is through one's diet. Other essential nutrients, like dietary minerals, essential amino acids or essential fatty acids do not fall under this category.

Types of vitamins

Vitamins can be water soluble (they dissolve easily in water) or fat soluble (they are absorbed through the intestines with the help of lipids). There are 13 vitamins, listed below based on their solubility.


  • Vitamin B1, also known as thiamine, deficiency disease is beriberi.
  • Vitamin B2, also known as riboflavin, deficiency disease is ariboflavinosis.
  • Vitamin B3, or niacin, deficiency disease is pellagra.
  • Vitamin B5, pantothenic acid, deficiency disease is paresthesias.
  • Vitamin B6, pyridoxine, no known deficiency disease.
  • Vitamin B7, biotin, no known deficiency disease.
  • Vitamin B9, folic acid, no known deficiency disease.
  • Vitamin B12, cyanocobalamin, deficiency disease is pernicious anemia.
  • Vitamin C, ascorbic acid, deficiency disease is scurvy.


  • Vitamin A, retinal, deficiency disease is night blindness and keratomalacia.
  • D-complex vitamins (D1, lamisterol; D2, ergocalciferol; D3, calciferol; D4, dihydrotachysterol and D5, dehydrositosterol) all have the same deficiency disease, which is rickets.
  • Vitamin E, tocopherol, with no known deficiency disease.
  • Vitamin K, naphthoquinone, with no known deficiency disease.

Deficiency and excess

Organisms can survive for quite some time without vitamins, but going for prolonged periods of times will result in a deficiency disease, which can often be painful and/or deadly. Likewise, when taken in excess, fat-soluble vitamins (which can be stored in the body) can cause toxicity when too much of them are consumed.