A double-blind, placebo-controlled study, appearing in Molecular Nutrition and Food Research (2014 July; 58(7): 1465-73) looked at the effect folate supplementation had on women with polycystic ovary syndrome (PCOS). The subjects were 81 obese women between the ages of 18 and 40 (weighing between 132 and 243 pounds), with PCOS. They were randomly divided to receive either 5 mg/day of folate, 1 mg/day of folate or a placebo during the eight week study. Blood tests were taken at the beginning and end of the study to check sugar metabolism and blood lipids.

The placebo group and the group receiving 1 mg/day of folate had negligible improvement. Those receiving 5 mg/day of folate had reduced homocysteine, lower cholesterol, improved HDL/LDL ratio (better “good” cholesterol to “bad” cholesterol ratio), improvement in insulin resistance score. The authors conclude, “5 mg/day folate supplementation for 8 weeks among women with PCOS had beneficial effects on metabolic profiles.”