Vitamin B12

Background Vitamin B12 is an essential water-soluble vitamin that is commonly found in a variety of foods, such as fish, shellfish, meat, eggs, and dairy products. Vitamin B12 is frequently used in combination with other B vitamins in a vitamin B complex formulation. Vitamin B12 is important in DNA synthesis.…

Vitamin A (retinol)

Background Vitamin A is a fat-soluble vitamin that comes from two sources: preformed retinoids and provitamin carotenoids. Retinoids, such as retinal and retinoic acid, are found in animal sources such as liver, kidney, eggs, and dairy products. Carotenoids, such as beta-carotene (which has the highest vitamin A activity), are found…

Thiamine (Vitamin B1)

Background Thiamine (also spelled "thiamin") is a vitamin, formerly known as vitamin B1. Thiamine was one of the first compounds recognized as a vitamin. Thiamine is involved in many body functions, including nervous system and muscle function, the flow of electrolytes in and out of nerve and muscle cells, digestion,…

Zinc

Background Zinc is a trace mineral that is needed for many important functions in the body. The human body contains approximately 2-3 grams of zinc, mostly in the skeletal muscles and bones. Zinc is also found in the kidney, pancreas, retina, teeth, hair, skin, liver, blood cells, prostate, and testes.…

Vitamin K

Background The name "vitamin K" refers to a group of chemically similar fat-soluble compounds called naphthoquinones. Vitamin K1 (phytonadione) is the natural form of vitamin K, which is found in plants and provides the primary source of vitamin K to humans through dietary consumption. Vitamin K2 compounds (menaquinones) are made…