Vitamins: Vitamin Properties

Vitamin A was the first vitamin to be isolated. It is obtained from carotene and occurs in green and yellow vegetables, egg yolk, butter, and cod liver oil and other seafood products. It is essential to growth, protects the skin, and prevents night blindness. Because it is fat soluble, it can build up in the body and be toxic if taken in excess.

Vitamin B at first was thought to be just one coenzyme. The isolation of what became known as thiamin, or B1, in 1926 showed that vitamin B had to have more than one factor, because the antiberiberi factor was heat sensitive and other factors were thought to be heat stable. The second factor to be discovered, riboflavin or vitamin B2, promotes healthy skin and good vision. As more related substances were identified, the group was renamed the “vitamin B complex.” Vitamin B3, also known as niacin or nicotinic acid, functions in the prevention of pellagra, a disease marked by gastrointestinal disorders and dermatitis. Vitamin B6, or pyridoxine, aids in nutrient metabolism. Folic acid, or folacin, once known as vitamin B9, has a role in human reproduction and promotes the production of red blood cells. Vitamin B12, or cobalamin, has been found to prevent pernicious anemia and certain nervous system disorders. Pantothenic acid and biotin, also factors of the B complex, function in the metabolism of nutrients.