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The Investigation of Vitamin D and Menstrual Cycles Trial, the inVitD Trial: A Phase II Clinical Trial
NCT05050916 · View on ClinicalTrials.gov ↗
Study Summary
Background: About 1.5 million U.S. women of reproductive age are estimated to be infertile. Many more have difficulty getting pregnant. Menstrual cycles are an indicator of a woman's general health. Menstrual cycle changes may predict difficulties in getting pregnant. Researchers want to see what role vitamin D may play in menstrual cycle health. Objective: To examine the effect of vitamin D supplementation on the hormones that come from the brain and the ovary during a menstrual cycle. Eligibility: Women aged 19-40 who have spontaneous menstrual cycles (are not taking any hormones) less than 50 days in length. Design: Participants will fill out a screening survey about their demographics and health history. It will take 5-10 minutes to complete. Participants will have 3 study visits. Participants who have low vitamin D and move to Phase 2 will receive 50000 IU//week of vitamin D supplement. Participants who do not have low vitamin D will receive placebo. If they have low vitamin D, they will not get the placebo. They will take the capsules by mouth, once per week, for 3 menstrual cycles (or about 90 days). Participants will have physical exams. Their height, weight, body fat percentage, blood pressure, and waist-hip ratio will be measured. They will give blood samples. They will self-administer vaginal and oral swabs. Participants will keep a daily menstrual diary. They will do daily home ovulation testing. They will collect urine at home. Some women may collect menstrual blood at home. Participants will fill out an online survey. It will ask about their health, diet, and physical activity; birth control use; pregnancy history; menstrual cycle; smoking and drinking habits; education; and occupation. It will take 20-30 minutes to complete. Participation will last for four menstrual cycles (about 4 months).
Conditions Studied
Interventions
- OTHER Placebo
- DIETARY_SUPPLEMENT Vitamin D
Study Locations (2)
Michigan
- Henry Ford Health System — Detroit
North Carolina
- NIEHS Clinical Research Unit (CRU) — Research Triangle Park
Trial Details
| Field | Value |
|---|---|
| Enrollment Target | 57 participants |
| Start Date | 2023-03-17 |
| Est. Completion | 2024-06-27 |
| Phase | Phase 2 |
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Full Details on ClinicalTrials.gov ↗What the Registry Record Tells You About NCT05050916
The ClinicalTrials.gov registry entry for NCT05050916 describes a study currently listed as completed. It is categorized as Phase 2, which is the standard way researchers label where a study sits along the investigational pathway from early safety work through later efficacy and post-marketing evaluation. The registered enrollment target is 57 participants, a figure that helps gauge the scale of data the investigators plan to collect. The listed sponsor is National Institute of Environmental Health Sciences (NIEHS), which has 75 total studies on file at ClinicalTrials.gov, and sponsors are the parties responsible for study design, oversight, and regulatory filings.
The record links to 1 condition, with Reproductive Issues appearing as the primary indexed condition, and to 2 interventions — of which Placebo is the first listed. Interventions can include drugs, devices, procedures, behavioral programs, or observational arms, and each is tracked as a separate registry field so that downstream queries can filter accurately. When a trial lists multiple interventions, it usually reflects a multi-arm design or a comparison protocol rather than a single treatment being tested in isolation. The brief summary published in the registry is the clearest source of protocol intent and should be read before drawing conclusions from any sidebar tags.
Geographic footprint matters for practical reasons: NCT05050916 reports 2 study locations spanning 2 distinct geographic areas — top geographies include Michigan, North Carolina. A larger site network tends to correlate with broader recruitment capacity, but it does not imply anything about study quality, and site-level enrollment status can diverge from the overall registry status shown above. Every data point on this page comes from the public ClinicalTrials.gov dataset and is reproduced here for reference only; it is not a medical recommendation, an endorsement of the sponsor, or an invitation to enroll. Verify current status, eligibility criteria, and contact details directly at ClinicalTrials.gov, and discuss any participation decision with your own healthcare provider.
Frequently Asked Questions
What is clinical trial NCT05050916 about?
NCT05050916 is a clinical study titled "The Investigation of Vitamin D and Menstrual Cycles Trial, the inVitD Trial: A Phase II Clinical Trial". Background: About 1.5 million U.S. women of reproductive age are estimated to be infertile. Many more have difficulty getting pregnant. Menstrual cycles are an indicator of a woman's general health. Menstrual cycle changes may predict difficulties in getting pregnant. Researchers want to see what r...
What is the current status of trial NCT05050916?
This trial is currently completed. It is a Phase 2 study. The enrollment target is 57 participants. The study started on 2023-03-17. Estimated completion is 2024-06-27.
What conditions does trial NCT05050916 study?
This clinical trial studies the following conditions: Reproductive Issues. These conditions were identified from the trial registry and reflect the primary focus areas of the research.
What interventions are being tested in trial NCT05050916?
The interventions under investigation include: Placebo (OTHER), Vitamin D (DIETARY_SUPPLEMENT). Each intervention is being evaluated for safety and efficacy as part of this clinical study.
Who is sponsoring clinical trial NCT05050916?
This trial is sponsored by National Institute of Environmental Health Sciences (NIEHS), which has 75 total clinical trials registered on ClinicalTrials.gov. The sponsor is responsible for the study's design, funding, and regulatory compliance.
Where is trial NCT05050916 being conducted?
This trial has 2 study locations across Michigan, North Carolina. Contact the study sites directly through ClinicalTrials.gov for enrollment availability.
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