The effect of Zn supplementation on Zn status depends on the iron status in physically active women

Abstract

Exercise can cause change of mineral levels by electrolyte and water loss through sweat. Zinc is known to be involved in exercise‐induced metabolic responses during exercise, so adequate zinc nutrition seems to improve exercise tolerance. The prevalence of iron deficiencies are known to be high in some physically active women. The iron nutrition status influences Zn status through competing for a common transporter in the intestinal absorption. This study investigates whether the iron status can influence the effect of Zn supplementation on serum Zn level. Female basketball collegiate players were supplemented 2 months with zinc 50mg as zinc gluconate. Bloods were collected before and after exercise at the beginning and end of 2‐mo. study period. The serum concentrations of Fe and Zn were measured by neutron activation analysis method. Half of athletic females before Zn supplementation showed a state of iron depletion (ID, serum ferritin <20 μg/L). Before supplementation, the serum Zn concentration was lower in athletes with ID than athletes without ID. After 2‐mo. Zn supplementation, the serum Zn level was higher in athletes with ID than without ID. showing lower Zn status with normal Fe status. Conclusively, this study suggests that the effect of Zn supplementation on serum zinc level in physical active women can depend on the iron status before supplementation. The 2‐mo. Zn supplementation can enhance the serum Zn concentration of athletic females with low iron status, but not with normal iron status. This study was supported by the MOST of Korea