Vitamin D and bacterial vaginosis (BV)

Studies have looked into vitamin D and its impact on bacterial vaginosis (BV). The results seem to suggest that vitamin D is extremely useful when used for asymptomatic BV (found in a test, but without symptoms of odour or discharge) but not for symptomatic BV. If you are going to go down this route, take 5,000IU or 10,000IU per day, not 2,000IU as the study did – it will increase the chances of a good outcome.

Vitamin D increases the expression of cathelicidin – a protein active in destroying bacteria. Researchers therefore postulated that BV may be a result of vitamin D deficiency, however evidence has not confirmed this.

     Study #1 – vitamin D deficient women with asymptomatic BV – good cure rate1

Researchers screened 218 women with asymptomatic BV for vitamin D deficiency (30ng/ml or less in a blood test), with 211 women (97 per cent) considered vitamin D deficient. These women were enrolled in the study. The women were then divided into two groups, one of whom would receive a placebo, while the other received vitamin D of 2,000IU per day for 15 weeks. The placebo group received two drops of sesame oil daily.

At 15 weeks, vitamin D status was reviewed and the Nugent score determined whether asymptomatic BV had been cured. Results of the study include:

  • Vitamin D levels increased from an average of 9.4 ng/ml to 28.4 ng/ml in the vitamin D group
  • Vitamin D levels increased from an average of 8.9 ng/m to 9.3 ng/ml in the placebo group
  • The cure rate of asymptomatic BV in the vitamin D group was 64.5 per cent and in the placebo group 19.2 per cent
  • Marital status, menstrual phase, and smoking all had significant relationships with BV, however once these were accounted for, the placebo group was 10.8 times more likely to still have BV at the end of the study
     Study #2 – High dose vitamin D in women with recurrent, symptomatic BV – didn’t make any difference2

At a sexually transmitted disease clinic, 118 women were put on high-dose vitamin D supplementation (nine doses of 50,000IU over 24 weeks) to see if it made a difference in the recurrence rates of BV, while also being treated with oral metronidazole twice daily for a week. While the vitamin D significantly increased vitamin D levels, it did not reduce recurrence rates of BV. Key findings of the study were:

  • Short-term, high dose vitamin D supplementation did not decrease recurrent BV in women who were at a high risk for STDs
  • Women receiving the vitamin D were just as likely as those in the control group, who did not receive the vitamin D, to have recurrences of BV at the end of the fourth and twelfth week visits
  • In a strange twist, at the end of the 24 weeks, 65 per cent of those receiving vitamin D were likely to have BV, while just 48 per cent of those in the control group did


  1.  Taheri M., et al. Treatment of vitamin D deficiency is an effective method in the elimination of asymptomatic bacterial vaginosis: A placebo controlled randomized clinical trial. Indian Journal of Medical Research, 2015.
  2.   2014 Nov;211(5):479.e1-479.e13. doi: 10.1016/j.ajog.2014.06.023. Epub 2014 Jun 17. A blinded, randomized controlled trial of high-dose vitamin D supplementation to reduce recurrence of bacterial vaginosis. Turner AN, Carr Reese P, Fields KS, Anderson J, Ervin M, Davis JA, Fichorova RN, Roberts MW, Klebanoff MA, Jackson RD.