Vitamins are nutrients required in very small amounts for essential metabolic reactions in the body. The term vitamin does not encompass other essential nutrients such as dietary minerals, essential fatty acids, or essential amino acids. Nor does the term refer to the large number of other nutrients that promote health, but are not strictly essential.Vitamins act both as catalysts and substrates in chemical reactions. When acting as a catalyst, vitamins are bound to enzymes and are called cofactors, for example vitamin K forms part of the proteases involved in blood clotting. Vitamins also act as coenzymes to carry chemical groups between enzymes, for example folic acid carries various forms of carbon groups (methyl, formyl or methylene) in the cell.Until the 1900's, vitamins were obtained solely through food intake. Many food sources contain different ratios of vitamins. Therefore, if the only source of vitamins is food, a seasonal, yearly or even daily change in diet also alters the ratio of ingested vitamins. Many vitamins can be stored by the body over a range of dosages and short term deficiencies (e.g. during a particular food growing season), do not always result in disease.Vitamins have been produced as commodity chemicals and made widely available as inexpensive pills for several decades allowing for consistent supplementation to dietary intake.Supplement FactsServing Size 4 capsules Servings Per Container: 30Vitamins/Antioxidants %DV Vitamin A 5000 i.u. ...............................100 Vitamin D 200 i.u. ................................50 Vitamin E 400 i.u. ................................1333 Vitamin C 100 mg .................................167 Grapeseed Extract (85% Proanthocyanidins 100mg Coenzyme b-complex & metabolic activators B1 100 mg .........................................6667 B2 100 mg .........................................5882 B3 200 mg .........................................1000 B5 200 mg .........................................2000 B6 100 mg .........................................5000 Folic Acid 400 mcg ................................3333 Paba 25 mg ........................................* Biotin 300 mcg.....................................100 Lipoc Acid 30 mg...................................* Minerals (elemented values)Calcium 500mg......................................50 Magnesium 500mg....................................125 Iron 25 mg.........................................139 Zinc 20mg..........................................133 Manganese 15 mg....................................750 Potassium 400 mg...................................13 Cooper 500 mg......................................25 Chromium 200 mcg...................................167 Selenium 100 mcg...................................143 Liptropic Nutrients & Digestive EnzymesCholine Bitartrate 200 mg............................* Inositol 100 mg......................................* Bromelain 100 mg.....................................* Be