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.