The body needs certain nutrients called vitamins, which are derived from food, to remain healthy and disease free. Metabolism, normal growth and general good health all depend on vitamin intake. Vitamins perform the important function of metabolizing other nutrients to start reactions in the body and provide energy. The United States Department of Agriculture or USDA has specified the minimum requirement of vitamins by the body.
Classes of Vitamins
Vitamins are classified into two types based on their solubility. Vitamins A, E, D and K are known as fat soluble vitamins, which can be stored in the body. Fat soluble vitamins contain hydrogen, carbon and oxygen.
Vitamin C or ascorbic acid and vitamins of the B group are water soluble vitamins, which cannot be stored in the body. Apart from hydrogen, carbon and oxygen, these vitamins contain nitrogen and sometimes sulfur. Vitamin B includes vitamin B1 or thiamine, vitamin B2 or riboflavin, vitamin B3 or niacin, vitamin B5 or pantothenic acid, vitamin B6 or pyridoxine, vitamin B7 or biotin, vitamin B9 or folate/folic acid and vitamin B12.
General Functions of Vitamins
Vitamins play a major role in the digestion and metabolism of food consumed. They enable the nutrients to be metabolized and absorbed, while converting fats and carbohydrates into energy. Moreover, they combine with proteins and produce enzymes. Vitamins are required for the production of antibodies and thus ensure a strong immune system. Finally, they help to form blood cells, bones, chemicals and hormones of the nervous system, and also bind tissues and strengthen cells.
Specific Functions of Different Vitamins
While all the vitamins have general functions, some vitamins perform specific functions. Vitamin A is required for good vision, healthy cells and bones, strong immunity, healthy skin and body linings and reproductive health. The group of B complex vitamins is essential for a number of bodily functions and converting food into energy. Further, each one of the group has special functions. Vitamin B1 converts carbohydrates into energy, while Vitamin B2 works with the other B vitamins to enable growth and release energy. Vitamin B3 aids digestion and maintains a healthy nervous system and skin. Pantothenic acid and biotine are required for metabolism and growth, and Vitamin B6 is needed for formation of red blood cells and brain functions. Folate/folic acid is responsible for protein production, RNA and DNA, so it is essential at every stage of life. Vitamin B12 also forms blood cells, and is required for metabolism and a healthy central nervous system.
Vitamin C, like vitamins A and E, is an antioxidant vitamin, and is responsible for strong bones, healthy blood vessels and skin and a strong immune system. Moreover, it builds and maintains tissues. Vitamin D plays a major role in preventing auto immune diseases, and also bone loss and osteoporosis by controlling the calcium levels in the blood. This is because it helps calcium to be properly absorbed by the body, and regulates the rate at which it is excreted. Vitamin E is often called the anti-aging vitamin, as it protects intracellular membranes and prevents tissue damage caused by harmful free radicals. Apart from its protective functions, vitamin E reduces the risk of liver related diseases like jaundice and combats the harmful side effects of prolonged use of antibiotics. Finally, vitamin K aids clotting of blood and metabolism of the bones.
Vitamins are substances required for a multitude of functions and the health of all the organs and systems of the body. Both fat soluble and water soluble vitamins perform some general functions like boosting metabolism and immunity, while each vitamin also has specific functions.