Dr. Bland reports, vitamins and minerals help regulate the conversion of food to energy in the body, and can be separated into two general categories: 

1. energy nutrients, which are principally involved in the conversion of food to energy,

2. protector nutrients, which help defend against damaging toxins derived from drugs, alcohol, radiation, environmental pollutants, or the body's own enzyme processes.

  Dr. Bland says, the B-complex vitamins and magnesium are energy nutrients, for they activate specific metabolic facilitators called enzymes, which control digestion and the absorption and use of proteins, fats, and carbohydrates. These nutrients often work as a team, their mutual presence enhancing the other's function.

  In the process of converting food to energy, oxygen-free radicals are produced that can damage the body and set the stage for degenerative diseases, including arthritis, heart disease, certain forms of cancer, and premature aging. Protector nutrients such as vitamin E, beta-carotene (a close relative of vitamin A), vitamin C, and the minerals zinc, copper, manganese, and selenium, play a critical role in preventing or delaying these degenerative processes. Vitamins E, A, and C work together as a team, protecting against breakdown and helping each other maintain adequate tissue levels.

  Dr. Berkson notes that vitamins and minerals are what make the chemical and electrical circuitry of the body work, and that the body's functioning is therefore profoundly affected by how nutrients either work together or against each other. Nutrients can help each other or inhibit each other when taken simultaneously. For example, iron is best absorbed when taken separately from pancreatic enzymes and should also not be taken with vitamin E. There are also certain nutrients that can help "potentiate" the other nutrients. For example, vitamin C taken with iron provides the maximum absorption of the iron.