CompletedPhase 2

The Investigation of Vitamin D and Menstrual Cycles Trial, the inVitD Trial: A Phase II Clinical Trial

United States57 participantsStarted 2023-03-17

Plain-language 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).

Who can participate

Age range19 Years – 40 Years

SexFEMALE

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AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

* INCLUSION CRITERIA: In order to be eligible to participate in this study, an individual must meet all of the following criteria: * Provision of signed and dated informed consent form * Stated willingness to comply with all study procedures and availability for the duration of the study * Having natural, spontaneous menstrual cycles (no hormonal therapy) less than 50 days in length. * Aged 19-40 years * Ability to take a vitamin D capsule and willing to adhere to the weekly regimen * If sexually active, use of a non-hormonal contraceptive method. EXCLUSION CRITERIA: An individual who meets any of the following criteria will be excluded from participation in this study: * No menstrual period in the last 50 days, or, a typical menstrual cycle length \<16 or \>49 days. * Use of a vitamin D supplement for more than one month and on more than 15 days out of each month. Volunteers will be asked to check their supplement label for vitamin D content. * Unwilling to abstain from taking non-study vitamin D supplements during the study or if already taking a medically-advised vitamin D supplement. * Use of a calcium supplement (including certain antacids) and unwilling to abstain from taking a calcium supplement during the study. * Known polycystic ovarian syndrome * Depo-provera use in the previous 12 months * Current use of any hormones, including birth control * Current use of a hormonal intrauterine device (IUD) * Current pregnancy or lactation, trying to become pregnant, or p…

What they're measuring

To examine the effect of vitamin D supplementation on hypothalamic-pituitary-ovarian axis hormones.

Timeframe: 60 months

Trial details

NCT IDNCT05050916

SponsorNational Institute of Environmental Health Sciences (NIEHS)

Sponsor typeNIH

Study typeINTERVENTIONAL

Primary completion2024-06-07