A surprising number of people take vitamin or mineral supplements each day as a kind of nutritional insurance - usually without understanding how they work and what they do. Nutrients such as riboflavin, vitamin C, zinc, and many others are essential to good health, but they are no substitute for food. In fact, vitamins and minerals are facilitators that enable the body to make use of the energy stored in food. These nutrients in and of themselves are of little value of the body. Simply taking vitamin and mineral supplements without eating food is like sending in bricklayers to build a wall, but neglecting to supply the bricks.

What vitamins do which is crucial to the normal maintenance of healthy cells, is perform an extraordinary range of functions in the human body. They not only help convert food into useable energy, but they also assist in the manufacture of blood cells, hormones, and the chemicals of the nervous system.

Vitamins are divided into two categories, which are water-soluble and fat-soluble. The four fat-soluble vitamins, A, D, E and K, are absorbed into body fat and may be stored for later use. If taken in excess, however, some fat-soluble vitamins can accumulate in toxic amounts. Vitamin C and the eight B vitamins are all water-soluble meaning that they dissolve in body fluid, and most of the excess is eliminated through sweat or urine. As a result, there is little concern about toxic overdoses although excessive doses of B6 can be toxic.

Minerals play a part in the maintenance of immune cells, in blood coagulation, in the synthesis of oxygen in the blood, in bone formation, and in numerous other functions. Some, such as calcium, phosphorus, and magnesium, are necessary in fairly large amounts. The need for others, known as trace minerals, is much smaller. In fact, although they are present in human tissue, a few of these trace elements play such dubious roles that they are considered nonessential. The essential trace minerals include iron, zinc, fluoride, and copper. Any of these minerals, whether essential or nonessential, is toxic if ingested in sufficient amounts for long enough periods.

How necessary are supplements? For years, controversy has raged between those who believe supplements are necessary and those who say that they are at best a waste of money and, at worst, a hazard to health. With few exceptions (notably vitamins D and K), the human body cannot make its own vitamins or minerals, so they must be obtained from foods. The traditional view holds that a balanced diet will supply all the vitamins and minerals that are necessary to maintain a good health.

The opposing argument for supplements is that many modern diets lack balance. In fact, they are so loaded with processed and refined foods that they cannot provide adequate amounts of essential vitamins and minerals. Furthermore, because many people skip regular meals and instead rely on fast foods, and nutritionally vacuous snacks, supplements may be a necessity. Other proponents of supplements claim that the chronic stress bought on by fast-paced lives can increase our need for these important nutrients.