Quantitative relations between baseline iron status , study duration , and iron dose on changes in iron-status biomarkers , which were generated from the meta-analyses , can be used to predict effects of trials of iron supplementation and fortification and to design iron-intervention programs
BACKGROUND The response of status biomarkers to an increase in iron supply depends on several physiologic and environmental factors , which make it difficult to predict the outcome of an intervention .
OBJECTIVE We assessed effects of baseline iron status , sex , menopausal status , duration of intervention , iron form , and daily dose on the change in iron status in response to iron supplementation .
Iron supplementation improves endurance after training in iron-depleted, nonanemic women.
Our objective was to investigate the effects of iron depletion on adaptation to aerobic exercise , assessed by time to complete a 15-km cycle ergometer test . Forty-two iron-depleted ( serum ferritin < 16 microg/l ) , nonanemic ( Hb > 12 g/dl ) women ( 18 - 33 yr old ) received 100 mg of ferrous sulfate ( S ) or placebo ( P ) per day for 6 wk in a r and omized , double-blind trial . Subjects trained for 30 min/day , 5 days/wk at 75 - 85 % of maximum heart rate for the final 4 wk of the study . There were no group differences in baseline iron status or in 15-km time . Iron supplementation increased serum ferritin and decreased transferrin receptors in the S compared with the P group . The S and P groups decreased 15-km time and respiratory exchange ratio and increased work rate during the 15-km time trial after training . The decrease in 15-km time was greater in the S than in the P group ( P = 0.04 ) and could be partially attributed to increases in serum ferritin and Hb . These results indicate that iron deficiency without anemia impairs favorable adaptation to aerobic exercise
Quantitative relations between baseline iron status , study duration , and iron dose on changes in iron-status biomarkers , which were generated from the meta-analyses , can be used to predict effects of trials of iron supplementation and fortification and to design iron-intervention programs
BACKGROUND The response of status biomarkers to an increase in iron supply depends on several physiologic and environmental factors , which make it difficult to predict the outcome of an intervention .
OBJECTIVE We assessed effects of baseline iron status , sex , menopausal status , duration of intervention , iron form , and daily dose on the change in iron status in response to iron supplementation .