The Investigation of Vitamin D and Menstrual Cycles Trial, the inVitD Trial: A Phase II Clinical … (NCT05050916) | Clinical Trial Compass
CompletedPhase 2
The Investigation of Vitamin D and Menstrual Cycles Trial, the inVitD Trial: A Phase II Clinical Trial
United States998 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 range
19 Years – 40 Years
Sex
FEMALE
See this in plain English?
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…
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
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)