Dr. Joseph M. Miller DO - ROOT Cause Supplements, LLC

https://drjosephmillerobgyn.com

Vitamin D3 Benefits Several Aspects of PCOS

 

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women of reproductive age, frequently associated with menstrual irregularities, hyperandrogenism, and infertility. Vitamin D deficiency is highly prevalent in PCOS and may contribute to impaired ovarian function and hormonal imbalance. This prospective, double-blind, placebo-controlled RCT investigated whether high-dose vitamin D3 supplementation could improve ovarian function in women with PCOS.

 

The study was conducted across eight sites in Hungary between 2016 and 2020 and included 84 premenopausal women (≥18 years) diagnosed with PCOS according to the revised Rotterdam criteria, with serum 25-hydroxyvitamin D (25(OH)D) levels of 10–30 ng/mL and BMI<36. Exclusion criteria included hypercalcemia, other metabolic disorders, and recent vitamin D supplementation (>1,000 IU) or metformin/hormonal therapy.

 

Participants were randomized into two groups: the D12 group received placebo for 12 weeks followed by vitamin D3 (30,000 IU/week) for 12 weeks, while the D24 group received vitamin D3 (30,000 IU/week) for 24 weeks. Women with low dietary calcium intake (<1000 mg/day) also received calcium citrate 400 mg/day.

 

Primary endpoints were ovulation rate (luteal-phase progesterone >10 ng/mL considered “responsive”) and menstrual cycle regularity (recorded in patient diaries). Secondary endpoints included serum hormonal changes and ovarian morphology assessed by transvaginal ultrasonography (TVUS). Outcomes were assessed at baseline, 12, and 24 weeks.

 

Serum 25(OH)D increased significantly after 12 weeks of vitamin D3 supplementation, stabilizing above 30 ng/mL in 95% of participants (mean >45 ng/mL). No further increase was observed after an additional 12 weeks of treatment in the D24 group.

 

After 12 weeks, both groups demonstrated significant improvements in menstrual cycle length, particularly among women with more severe oligomenorrhea. Approximately two-thirds of participants experienced shorter, more regular cycles. Ovulation rates also improved significantly, most notably in women with a higher LH/FSH ratio (>2). Hyperandrogenic participants also showed a significant reduction in mean testosterone levels. Ovarian morphology improved in over half of the participants, although differences between groups were not statistically significant. No safety issues or adverse events were reported.

 

Weekly high-dose vitamin D3 supplementation significantly improved ovulation rates and menstrual regularity, as well as ovarian morphology in women with PCOS and vitamin D deficiency. Benefits were greatest among hyperandrogenic phenotypes, supporting vitamin D3 as a promising adjunctive therapy for PCOS management.

 

Note: Thorne offers a range of Vitamin D formulations to support diverse individual needs.