Could vitamin d boost fertility? new study investigates

NCT ID NCT05050916

Completed Knowledge-focused Sponsor: National Institute of Environmental Health Sciences (NIEHS) Source: ClinicalTrials.gov ↗

First seen Jun 27, 2026 · Last updated Aug 05, 2026 · Updated 6 times

Summary

This completed Phase 2 trial looked at whether vitamin D supplements affect hormones linked to healthy menstrual cycles. Nearly 1,000 women aged 19-40 with natural cycles took either high-dose vitamin D (50,000 IU/week) or a placebo for about 3 months. Researchers measured hormone levels in urine and blood to see if vitamin D improves ovulation and fertility indicators.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance: Vitamin D (cholecalciferol)
What this could lead to: If it works, this could show that vitamin D helps regulate menstrual cycles, potentially improving fertility understanding.
What could go wrong: This is a completed Phase 2 trial, so results are preliminary. The study is observational in nature and does not test a treatment for infertility directly.

This is an AI summary of the original study and may miss details. Read our disclaimer.

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As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

REPRODUCTIVE ISSUES

Contacts and locations

Locations

Henry Ford Health System

Detroit, Michigan, 48187, United States
NIEHS Clinical Research Unit (CRU)

Research Triangle Park, North Carolina, 27709, United States

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