The effects of calcium-vitamin D and metformin on polycystic ovary syndrome: a pilot study

Taiwan J Obstet Gynecol. 2009 Jun;48(2):142-7. doi: 10.1016/S1028-4559(09)60275-8.


Objective: The aim of this study was to evaluate the effects of calcium-vitamin D and metformin on the menstrual cycle and ovulation in patients with polycystic ovary syndrome (PCOS).

Materials and methods: In this pilot study, 60 infertile PCOS patients were enrolled in a randomized clinical trial and divided into three equal groups. Group 1 received 1,000 mg of calcium and 400 IU of vitamin D per day, orally. Group 2 received the same as Group 1, plus 1,500 mg/day of metformin. Group 3 received 1,500 mg/day of metformin. The patients were treated for 3 months and followed up for a further 3 months. Regularity of menses, number of large follicles (> or = 14 mm) and pregnancy rates were compared among the three groups.

Results: Generalized estimating equation tests showed that the number of dominant follicles (> or = 14 mm) during the 2-3 months of follow-up was higher in the calcium-vitamin D plus metformin group than in either of the other two groups (p = 0.03).

Conclusion: The effects of metformin and calcium-vitamin D in regulating the menstrual cycle suggest that they could also be effective for the treatment of anovulation and oligomenorrhea, with possible consequences for pregnancy rates in PCOS patients.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Adult
  • Calcium / administration & dosage*
  • Drug Therapy, Combination
  • Female
  • Follow-Up Studies
  • Humans
  • Hypoglycemic Agents / administration & dosage
  • Infertility, Female / drug therapy*
  • Menstrual Cycle / drug effects
  • Metformin / administration & dosage*
  • Ovulation / drug effects
  • Pilot Projects
  • Polycystic Ovary Syndrome / drug therapy*
  • Pregnancy
  • Pregnancy Rate
  • Vitamin D / administration & dosage*
  • Vitamins / administration & dosage
  • Young Adult


  • Hypoglycemic Agents
  • Vitamins
  • Vitamin D
  • Metformin
  • Calcium