The effects of lean beef supplementation on the iron status of college athletes

Abstract

Jocelyn Johnson, Danielle Burke, Matthew Vukovich, Kendra KattelmannHealth and Nutritional Sciences Department, South Dakota State University, Brookings, SD, USAAbstract: The purpose of this study was to determine whether weekly supplementation with nine ounces of prepackaged lean beef sticks could maintain the iron status of college endurance athletes. Thirty-four college endurance athletes (20 female, 14 male) were stratified by sex, baseline serum ferritin concentration, and use of iron supplements, and randomized into an intervention (n = 18) or control (n = 16) group. The participants in the intervention group supplemented their usual diet with nine ounces of prepackaged lean beef sticks per week and a daily multivitamin/mineral supplement containing 18 mg iron. The participants in the control group consumed their normal diet and the daily multivitamin/mineral supplement only. Body composition, dietary intake, and blood markers of iron status (hemoglobin, hematocrit, serum iron, serum ferritin, and total iron binding capacity) were measured at baseline and postintervention. A two-way analysis of variance with group and time as treatment factors was used to determine the main effect of beef supplementation on variables measured. None of the participants in this study was categorized as iron deficient at baseline or postintervention. Heme iron intake was significantly greater (P < 0.003) in the intervention group (3.1 ± 0.3 mg per day) than in the control group (1.5 ± 0.3 mg per day) as a result of the intervention. The intervention participants had significant improvements in hematocrit concentrations; there were, however, no differences in blood iron parameters of serum iron, hemoglobin, serum ferritin, or total iron binding capacity as a result of the intervention. The results of this study suggest that daily intake of bioavailable iron may attenuate the effects of exercise on the iron status of endurance athletes.Keywords: bioavailable iron, iron status, iron deficiency, heme iron, endurance athletes, lean beef