Sports nutrition is one of the largest categories within the nutritional supplement and functional foods industries. Yet, even though there are roughly equal numbers of men and women participating in sports, women only account for about one-third of the subjects in sports-related research studies, and the number is even smaller for studies focusing on sports nutrition.

This lack of research has led to inappropriate nutritional recommendations and biased marketing that fails to address the dietary needs of female athletes.

This balance of macronutrients in the diet is critically important for the female athlete. In her book, "The New Power Eating," Susan Kleiner, Ph.D., RD, stated, "The balance needed between protein, carbohydrate and energy availability is particularly profound for women in sports because female reproductive hormones are linked to the metabolic pathway. When energy and/or carbohydrate and protein intakes are deficient, reproductive function declines. This has a domino effect on overall health, leading to diminished thyroid function, bone mineral metabolism, immune function, gastrointestinal [GI] function, and maintenance of body tissues and organs. Ultimately physical performance declines."

To supplement a healthy, balanced diet, supplemental forms of selec micronutrients are recommended. One of the most important of these is iron. Not only is iron needed to prevent iron-deficiency anemia in menstruating women, it is crucial for oxygen transport, necessary for optimal performance. To prevent iron overload, increasing the consumption of iron-containing foods is usually recommended over iron supplementation (J Int Soc Sports Nutr. 2015;12:38). However, if dietary sources are not sufficient, supplementation with the recommended dietary intake (RDI) of iron, 18 mg, may be needed. Ferrous sulfate or ferrous gluconate are iron salts that tend to be better absorbed with less GI upset.

Another mineral needed by female athletes is calcium. Ideally, calcium can be obtained through the diet by consuming a combination of dairy products and green leafy vegetables. However, many female athletes—particularly those who have a dairy intolerance or allergy, or who are vegan or strict vegetarian—will have difficulty getting an adequate amount through diet alone, so supplementation is necessary.