Administration of B-group vitamins reduces circulating homocysteine in polycystic ovarian syndrome patients treated with metformin: a randomized trial

Hum Reprod. 2005 Jun;20(6):1521-8. doi: 10.1093/humrep/deh825. Epub 2005 Mar 24.


Background: The aim of the current study was to assess the effects of B-group vitamins and folic acid administration on serum levels of homocysteine (Hcy) in patients with polycystic ovarian syndrome (PCOS) on short-term metformin treatment.

Methods: Patients were randomly assigned to one of three treatment groups. Group 1 patients (n = 20) received metformin (850 mg twice daily); group 2 patients (n = 20) received metformin (850 mg twice daily) and B-group vitamins (vitamin B1, 250 mg; vitamin B6, 250 mg; vitamin B12, 1000 microg twice daily); and group 3 patients (n = 20) received metformin (850 mg twice daily) and folic acid (174 microg twice daily). In all groups, lipid profiles and plasma total Hcy, vitamin B12, folic acid and glucose levels were recorded at baseline and at 3 months.

Results: A 26.5% increase in Hcy levels was seen after 12 weeks of metformin therapy, while 21.17 and 8.33% decreases in Hcy levels were detected when B-group vitamins or folic acid plus metformin were given respectively. There were no statistically significant differences recorded in insulin sensitivity using homeostasis model assessment in the three groups.

Conclusion: These findings suggest that B-group vitamins and folic acid administration counteract the Hcy-increasing effect seen with metformin therapy.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Blood Glucose / analysis
  • Body Weight / drug effects
  • Dose-Response Relationship, Drug
  • Female
  • Folic Acid / therapeutic use*
  • Homocysteine / blood*
  • Humans
  • Lipids / blood
  • Menstrual Cycle / drug effects
  • Menstrual Cycle / physiology
  • Metformin / adverse effects
  • Metformin / therapeutic use*
  • Ovulation / drug effects
  • Ovulation / physiology
  • Polycystic Ovary Syndrome / blood
  • Polycystic Ovary Syndrome / drug therapy*
  • Vitamin B Complex / therapeutic use*


  • Blood Glucose
  • Lipids
  • Homocysteine
  • Vitamin B Complex
  • Metformin
  • Folic Acid