Vitamin amino acids. Most vitamins are not single molecules, but groups of related molecules called vitamers. For example, vitamin E consists of four tocopherols and four tocotrienols. The thirteen vitamins required by human metabolism are: vitamin A (retinols and carotenoids), vitamin B (thiamine), vitamin B (riboflavin), vitamin B (niacin), vitamin B (pantothenic acid), vitamin B (pyridoxine), vitamin B (biotin), vitamin B (folic acid or folate), vitamin B (cobalamins), vitamin C (ascorbic acid), vitamin D (calciferols), vitamin E (tocopherols and tocotrienols), and vitamin K (quinones). Vitamins have diverse biochemical functions. Some forms of vitamin A function as regulators of cell and tissue
Vitamin World Vitamin World Vitamin World USA Corporation is a global retailer of vitamins and nutritional supplements and is headquartered on Long Island, New York in the United States. Vitamin World was founded in 1977 by Arthur Rudolph and is headquartered in Great River, New York. Vitamin World was a subsidiary of NBTY Inc. NBTY manufactured and sold products under the "Vitamin World" label and currently does so under the "Holland and Barrett" and "Puritan's Pride" labels. Under NBTY, Vitamin World had retail stores in North America, Holland and Barrett currently has retail stores in the United Kingdom, and Puritan's Pride is