Vitamin D's effect on ovulation in women with PCOS
Official title: A Randomized Double-blind Controlled Trial on the Effect of Vitamin D on Ovulation Rate of Women With Polycystic Ovary Syndrome
Run by The University of Hong Kong · NCT04650880 · Data updated 2026-11-12
This study tests if taking vitamin D can help women with PCOS have more regular ovulation.
Quick facts
| Study type | Interventional |
|---|---|
| Ages | 18 Years to 40 Years |
| Sex | Women only |
| Enrollment | 220 (estimated) |
| Sponsor | The University of Hong Kong Academic / other |
| Locations | 3 sites (Hong Kong and 2 other locations) |
| Status | Recruiting |
| Started | January 26, 2021 |
| Main results expected | December 31, 2024 |
| Study ends | December 31, 2026 |
| Registry record updated | May 14, 2024 |
| Trial ID | NCT04650880 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Ideal candidates are premenopausal women aged 18-40 with irregular menstrual cycles and diagnosed with PCOS according to the Rotterdam criteria.
✕Probably not a fit
Patients currently using hormonal medications or those with conditions affecting vitamin D metabolism may not benefit from this study.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
This clinical trial investigates the impact of vitamin D supplementation on the ovulation rate in women diagnosed with polycystic ovary syndrome (PCOS). It is a randomized double-blind controlled trial where participants will receive either vitamin D or a placebo over a one-year period. The study aims to determine if vitamin D can improve ovulation rates either spontaneously or in conjunction with an oral ovulation induction agent. Participants will be monitored for reproductive, endocrine, and metabolic outcomes throughout the trial.
Why it matters
Potential benefit: If successful, this study could provide a new, non-invasive treatment option to improve ovulation rates in women with PCOS.
How similar studies have gone: While the approach of using vitamin D for ovulation in PCOS is promising, it remains relatively novel and has not been extensively tested in similar studies.
Who can join: the full rules
Show full inclusion / exclusion criteria
Inclusion Criteria: * Premenopausal * Aged 18-40 years * Irregular long menstrual cycles (\>35 days) * PCOS according to the Rotterdam criteria * Agree for transvaginal ultrasound Exclusion Criteria: * Use of hormonal medication (including contraception) within 3 months prior to study inclusion, except the use of a progestogen to induce withdrawal bleeding every 3 months * History of any medical condition or medications that may predispose to vitamin D sensitivity, altered vitamin D metabolism and/ or hypercalcemia, including active tuberculosis or current therapy for tuberculosis, sarcoidosis, history of renal/ ureteral stones, parathyroid disease, renal or liver failure or current use of anti-convulsants * Use of insulin-sensitizing drugs, lipid lowering drugs or anti-hypertensive * Anticipated to use the above medications in the coming one year * Known type 2 diabetes mellitus * Refusal to join the study * Abnormal blood calcium level For those on supplements, we asked them to stop their own supplements.
Where it's running
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Kwong Wah Hospital
Hong Kong, Hong Kong Recruiting -
Queen Mary Hospital, University of Hong Kong
Hong Kong, Hong Kong Recruiting -
Princess Margaret Hospital
Hong Kong, Hong Kong Not yet recruiting
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How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.