The primary goal of any nutrition program for an athlete is to meet nutritional requirements, assure optimum performance, and cope with the stresses of physical exertion. The use of certain dietary supplements may be a useful part of this program. However, dietary supplements are just that-supplements, not substitutes, for a good diet.

Nutritional supplementation may be necessary for athletes in special conditions such as heavy menstrual bleeding, preconception and pregnancy, low calorie intakes or vegetarian diets; and other physiological or environmental factors that interfere with adequate intake or increase losses. In addition to these specific needs, many persons, and athletes in particular, may benefit from generous intakes of vitamins C and E. Optimal intakes of vitamin E particularly are difficult to achieve through unfortified conventional foods. Because of the oxidative stress associated with intense training programs of many athletes, the need for antioxidants may be increased.

The supplementation guidelines herein are based on the goal of providing safe intakes of individual nutrients to promote healthful training regimens and recovery periods. There is little definitive scientific evidence from human studies that supplemental intakes of vitamins and minerals beyond levels promulgated by the Recommended Dietary Allowances (RDA) provide significant ergogenic actions. However, inadequate intake of many essential nutrients can lead to impaired performance. Optimal intake of nutrients will not overcome deficits in training and consumption of excessive quantities of dietary supplements can be toxic and impair performance. The guidelines provided here are especially developed to be safe and to help athletes avoid potentially dangerous intakes.

The use of supplements is appropriate only in conjunction with a good diet. Dietary evaluation should be made by a qualified health professional and food intake patterns should be adjusted if necessary to promote optimal health. If a thorough dietary evaluation is not possible and cursory review of the athlete's dietary habits indicates possible reason for concern, prophylactic supplementation may be desirable. Even for those eating high quality and varied diets, certain supplements may be indicated. The following guidelines for supplementation are appropriate for a variety of individuals as well as sports and training activities. Ranges of intake are provided due to the differences in dietary patterns and nutrient needs among individuals, in training regimens and sports events, and other conditions. Importantly, these guidelines are designed to provide for supplemental intakes that are safe and will not result in untoward (adverse) effects

When supplementation is indicated, based on determination of an inadequate intake, or when an individual desires to take dietary supplements for "insurance" or for the supplement's health-promoting properties, it is important that intake levels be adequate but not excessive. Therefore, where recommendations exist, intake ranges are given.

Several abbreviations will be used in these Guidelines. Many refer to recommended nutrient intake levels. Definitions of abbreviations can be found in the Glossary at the end of this document. 

When supplementation is indicated, based on determination of an inadequate intake, or when an individual desires to take dietary supplements for "insurance" or for the supplement's health-promoting properties, it is important that intake levels be adequate but not excessive. Therefore, where recommendations exist, intake ranges are given. Several abbreviations will be used in these Guidelines. Many refer to recommended nutrient intake levels. Definitions of abbreviations can be found in the Glossary at the end of this document.