Many young female athletes are quite lean because of their enormous output of energy in the pursuit of their sports. This leanness can cause some of them to experience something called athletic amenorrhea, which means these young female athletes do not menstruate.
Athletic amenorrhea puts them in the surprising position of being in a similar category to women who are past menopause. Both groups of women have low levels of estrogen. This low level of estrogen leaves these young and otherwise seemingly healthy women at significant risk of developing heart disease.
A recent study indicates that supplements of folic acid can improve vascular health for these young female athletes.
"More research is needed to determine the lowest optimal dose of folic acid for athletic amenorrhoea which offers the maximum benefit. Folic acid supplementation is important because folic acid may not only decrease cardiovascular risks but also improve athletic performance for these women."
http://www.virtualmedicalcentre.com/news/Folic-acid-found-to-improve-vascular-function-in-amenorrhoeic-runners/15030