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.