Proteins can be used as a source of energy. Proteins are used for energy if carbohydrates are not available. Excess proteins may be converted to glucose or fat to be used for energy or stored as fat. The main sources of protein are meats, tuna, beans, milk, and other dairy products. The main building blocks of protein are called Amino Acids.
Vitamins are organic substances necessary for normal body metabolism, growth, and development.
Vitamins function as coenzymes which regulate the work of the enzymes. The body does not manufacture vitamins, but obtains them through the food we eat. Minerals are inorganic elements found in the body and food. Approximately 25 minerals have important roles in body functioning. Minerals are contained in all cells, especially those in bones, nails, and teeth.