Training for cross-country skiing and iron status.

Effects of iron supplements and training for cross-country skiing on hematological and iron status were studied in nine men and ten women from the U. S. Nordic ski team. Four men and five women received a multiple vitamin, multiple mineral supplement containing 18 mg iron for 8 months while five men and five women received a placebo. Fasting blood samples were taken from all skiers prior to supplementation (May) and in August, November, and January. Hemoglobin, hematocrit, plasma iron, total iron binding capacity (TIBC), percentage of transferrin saturation, serum ferritin, free erythrocyte porphyrin, and haptoglobin were measured on each sample. Hemoglobin, hematocrit, and TIBC were higher in November when both men and women skiers trained at altitude than in August. In January TIBC was further increased, haptoglobin was increased, hemoglobin for the men fell below May levels, and hematocrit returned to May levels. Skiers receiving iron had lower TIBC levels in November and January than the placebo group. Six women and two men had ferritin levels below 28 ng X ml-1, which suggests prelatent iron deficiency. Free erythrocyte porphyrin levels above 100 micrograms X dl-1 RBC were found in all skiers at some point during training. The results suggest that multivitamin, multimineral supplements containing iron have little effect on the iron status of cross-country skiers.

RCT Entities:   Population Interventions Outcomes