Folic acid supplementation improves vascular function in amenorrheic runners.

OBJECTIVE The purpose of this study was to determine if folic acid supplementation improves endothelial vascular function (brachial artery flow-mediated dilation; FMD) in amenorrheic runners. DESIGN Prospective cross-sectional study. SETTING Academic medical center in the Midwest. PARTICIPANTS Ten amenorrheic and 10 eumenorrheic women runners from the community volunteered for this study. INTERVENTIONS Each participant was treated with folic acid (10 mg/d) for 4 weeks. MAIN OUTCOME MEASURES Brachial artery FMD was measured before and after folic acid supplementation with standard techniques. RESULTS The brachial artery FMD response to reactive hyperemia improved after folic acid supplementation in amenorrheic women (3.0% +/- 2.3% vs. 7.7% +/- 4.5%; P = 0.02). In the eumenorrheic control group, there was no change in brachial artery FMD (6.7% +/- 2.0% vs. 5.9% +/- 2.6%; P = 0.52). CONCLUSIONS This study demonstrates that brachial artery FMD, an indicator of vascular endothelial function, improves in amenorrheic female runners after short-term supplementation with folic acid.