Vitamins are required in small quantities to perform many specific metabolic functions such as energy production, bone health, eye function, and neuromuscular function. After years of scientific research, there is no evidence, which suggests that vitamin supplementation enhances performance unless the athlete was low in that particular substance to begin with. Certain vitamins such as vitamin C and vitamin B6 are typically low in those with poor eating habits. Excessive vitamin intake especially the fat-soluble vitamins A, D, E, and K can be very harmful. For people eating a prudent diet you probably need no additional vitamin supplementation but, if your not sure, a simple multivitamin will not hurt.
Minerals also play an important role in the athletes performance.
Iron is required to transport oxygen to exercising muscle cells. Athletes that test low for iron should consider iron supplementation but do not over-supplement because high iron has been associated with heart disease. Calcium, phosphorus, and magnesium are important for the structural components of bone. Calcium, phosphorus, and magnesium for proper bone health can be supplemented using RDA recommendations. Females especially need to be concerned with proper calcium intake.