Why Does Your Body Need Vitamins?

Although vitamins are chemically unique, they all have the same basic function: to enable the normal functioning of the body and to promote good health. As defined in Sizer and Whitney's book, "Nutrition," a vitamin is an essential, noncaloric, organic nutrient that is vital to life and indispensable to the body's functions. They perform best when they are present in adequate amounts in the body, but they are needed only in tiny amounts. A balanced diet or any supplements you take usually supply sufficient vitamins to the body.

Benefits

According to "Vitamins," a 2010 article from the University of Maryland Medical Center, a diet high in vitamins can be the best defense against many diseases, specifically heart disease, stroke, and cancer. Unlike the nutrients carbohydrates, protein and fat, vitamins do not provide energy to the body. Instead, vitamins help to drive cell processes, such as the body's metabolism, cell production, tissue repair, and other vital processes.

Fat-Soluble Vitamins

The fat-soluble vitamins--A,D,E, and K--are found in fats and oils of foods. These vitamins are stored in the liver and fatty tissues until the body requires use of them. Fat-soluble vitamins have a variety of roles in the body. According to Sizer and Whitney, vitamins A and D act similarly to hormones, directing cells to convert one substance to another, or to store and release certain chemicals. Their effects are seen at the level of genes, influencing protein production. Sizer and Whitney also write that vitamin E flows throughout the body preventing oxidative destruction of tissues, while vitamin K is needed for blood to clot.

Water-Soluble Vitamins

Vitamin C and the B vitamins are water soluble. Unlike fat-soluble vitamins, the water-soluble vitamins do not get stored. They are easily absorbed and flow quickly through the bloodstream. It is important to choose foods that are rich in water-soluble vitamins in order to achieve the average recommended intake because these vitamins are easily excreted in the urine and constantly need to be replaced. According to Sizer and Whitney, these vitamins have a diverse role in the body. Vitamin C works as an antioxidant, protecting the body from free radicals, in addition to maintaining connective tissues in the body such as collagen. The B vitamins act as part of a coenzyme, which is a small molecule that combines with an enzyme to activate it. While the B vitamins have many complex functions, simply stated, they help the body use fuel supplied by nutrients. The active forms of the B vitamins assist in energy metabolism.

Vitamin Deficiency

Each vitamin has complex signs and symptoms which identify the body's deficiency of the particular vitamin. Vitamin deficiencies may result in many adverse effects. In general, when the body is deficient in certain vitamins it will struggle to perform essential functions such as wound healing, producing new cells, and protecting existing cells from oxidative damage. More specifically, the University of Maryland Medical Center says that a diet lacking in vitamin A results in increased susceptibility to infectious diseases and vision problems. Diets deficient in vitamin D result in bone disorders. Blood related disorders may occur from deficiencies in vitamins B-9, B-12, C, E, and K. These are just a number of negative symptoms of vitamin deficiencies that stress the importance of why the body needs vitamins.

A New Standard

The concept of the Recommended Dietary Allowance, or RDA, is slowly being replaced by the Daily Recommended Intake, or DRI, as a set standard for adequate daily vitamin consumption. The UMMC claims that the use of DRI values represents a shift in nutritional emphasis from preventing deficiencies to lowering the risks of chronic diseases, including cardiovascular disease, stroke, and cancer.