n. any of several organic chemical substances not synthesized by an animal and required in small quantities for normal metabolism, present in and obtained from the natural foods eaten by the animal. Human vitamins are also produced synthetically, and taken in pure form or in mixtures, as dietary supplements. Deficiencies of specific vitamins lead to certain specific disorders, such as scurvy, caused by an insufficiency of vitamin C (ascorbic acid). Most vitamins act as coenzymes or precursors to coenzymes, and are not consumed for energy production or incorporated into structural units of the cell. [ PJC ]

n. any of several related fat-soluble vitamins (such as retinol) essential for normal vision; it also prevents night blindness or inflammation or dryness of the eyes.
Syn. -- antiophthalmic factor, axerophthol. [ WordNet 1.5 ]

n. retinol (C20H30O), one of the substances also called vitamin A. It is also called more specifically vitamin A alcohol. It is a required factor for human nutrition. The USP unit of activity is equal to 0.30 micrograms of retinol.
Syn. -- retinol. [ WordNet 1.5 +PJC ]

n. dehydroretinol (C20H28O), one of the substances also called vitamin A. It has about 40% of the bioactivity of vitamin A1.
Syn. -- dehydroretinol. [ WordNet 1.5 +PJC ]

n. a group of water-soluble vitamins originally thought to be a single vitamin but now separated into several B vitamins.
Syn. -- B-complex vitamin, B complex, vitamin B complex, B vitamin. [ WordNet 1.5 ]

n. a B vitamin (C12H17N4OS)Cl that prevents beriberi and maintains appetite and growth. Same as thiamine.
Syn. -- thiamin, aneurin, antiberiberi factor. [ WordNet 1.5 ]

n. a B vitamin that is used to treat pernicious anemia.
Syn. -- cobalamin, cyanocobalamin. [ WordNet 1.5 ]

n. a B vitamin that prevents skin lesions and weight loss.
Syn. -- vitamin G, riboflavin, lactoflavin, ovoflavin, hepatoflavin. [ WordNet 1.5 ]

n. See nicotinamide.
Syn. -- nicotinamide. [ PJC ]

n. See nicotinic acid.
Syn. -- nicotinic acid. [ PJC ]

n. a B vitamin that is essential for metabolism of amino acids and starch.
Syn. -- pyridoxine, pyridoxal, pyridoxamine, adermin. [ WordNet 1.5 ]

n. a B vitamin that is essential for cell growth and reproduction. Also called folic acid
Syn. -- vitamin M, folic acid, folacin, pteroylglutamic acid, pteroylmonoglutamic acid. [ WordNet 1.5 ]

n. a mixture of water-soluble vitamins originally thought to be a single vitamin but now known to be a mixture of several compounds with vitaminic activity. Syn. -- B complex, vitamin B complex, vitamin B, B vitamin. [ WordNet 1.5 ]

n. a vitamin that prevents scurvy. Also called ascorbic acid.
Syn. -- ascorbic acid. [ WordNet 1.5 ]

n. any of several chemically related fat-soluble vitamins that prevent rickets. It is found in fish-liver oils, egg yolks and milk. Component vitamin D2 is also called calciferol, and vitamin D3 is called cholecalciferol.
Syn. -- calciferol, ergocalciferol, cholecalciferol. [ WordNet 1.5 ]

n. a fat-soluble vitamin that is essential for normal reproduction. It is found in vegetable oils, butter, and eggs.
Syn. -- tocopherol, alpha-tocopherol. [ WordNet 1.5 ]

n. same as vitamin B2.
Syn. -- vitamin B2, riboflavin, lactoflavin, ovoflavin, hepatoflavin. [ WordNet 1.5 ]

n., a B vitamin that aids in body growth.
Syn. -- biotin. [ WordNet 1.5 ]

n. (1929) [ from G. Koagulationsvitamin. ] either of two fat-soluble vitamins (vitamin K1 or vitamin K2) that help clot blood by participating in the fromation of prothrombin. Syn. -- naphthoquinone. [ WordNet 1.5 +PJC ]

n. one of the two K vitamins, (C31H46O2). It is fat-soluble and occurs naturally as the trans isomer. Chemically it is 2-methyl-3-phytyl-1, 4, -naphthoquinone.
Syn. -- phylloquinone, phytonadione, antihemorrhagic vitamin.. [ WordNet 1.5 +PJC ]

n. menadione, (C11H8O2) being chemically 2-methyl-1, 4, -naphthoquinone. Having no side chain in the 3 position, it cannot exert all functions of a true K vitamin and the designation as vitamin K3 has been discouraged [ MI11 ]
Syn. -- vitaminK2(0); menaphthone. [ WordNet 1.5 ]

n. same as vitamin Bc; folic acid. [ WordNet 1.5 ]

n. a water-soluble vitamin that maintains the resistance of cell and capillary walls to permeation.
Syn. -- bioflavinoid, citrin.) [ WordNet 1.5 ]

n. one of the two K vitamins, actually a mixture of homologous fat-soluble substituted naphthoquinones (called menaquinones), (C11H7O2[ C5H8 ]nH), where n may be 1 to 13 but is mostly 7 to 9. The term is also used for synthetic compounds resembling vitamin K2 and having the same physiological action. The individual components of vitamin K2 are also referred to by the number of isoprenyl units in the side chain (the number n in the formula), as for menadione, having no units at that position of the naphthaquinone ring, and also called vitamin K2(0) (and also called vitamin K3). [ MI11 ]
Syn. -- menaquinones, antihemorrhagic vitamin.. [ WordNet 1.5 +PJC ]