CompletedNot Applicable

Low vs. Moderate to High Dose Vitamin D for Prevention of COVID-19

United States1,475 participantsStarted 2020-11-30

Plain-language summary

The purpose of this study is to compare the risks of COVID-19 in individuals from Chicagoland communities randomized to low (400 IU/day) vs. moderate (4,000 IU/day) or high (10,000 IU/day) dose vitamin D.

Who can participate

Age range

18 Years

Sex

ALL

See this in plain English?

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

Subjects are able to participate if they: 1. Are 18 years or older. 2. Live or work in the Chicagloland area (Illinois counties: Cook, Lake, McHenry, DuPage, Kane, Kendall, Grundy, Will, and Kankakee; Indiana counties: Lake and Porter). 3. Are interested in vitamin D as a potential preventive measure against COVID-19 in which they self-administer a daily dose of vitamin D during the 9-month study period. 4. Are willing to attend the laboratory for drop-in appointments at UChicago Medicine or Rush University Medical Center every 3 months at 4 time points over a 9-month period for blood draws measuring COVID-19 antibodies, calcium, vitamin D and PTH levels. 5. Are willing to complete self-report measures at 4 time points over the course of 9 months by completing a 15-minute survey at intake by telephone or via web and 10-minute web-based follow-up surveys. Subjects are excluded from study participation if they: 1. Report ever having a positive COVID-19 PCR test result 2. Report being pregnant, planning to become pregnant, and/or report breastfeeding during the study period. 3. Report a history of chronic kidney disease, including a history of abnormal GFR and/or creatinine. 4. Report a history of hyperparathyroidism. 5. Report a history of increased falls. 6. Report a history of hypercalcemia. 7. Report a history of gastrointestinal absorptive disorders, including having undergone bariatric surgery. 8. Report a history of kidney stones (1 in past year or 2 in lifetime). 9. R…

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

SARS-CoV-2 Infection as Measured by Patient Report of Clinically Confirmed COVID-19 (or Viral PCR When Available)

Timeframe: Up to 9-months

Trial details

NCT IDNCT04868903

SponsorUniversity of Chicago

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2024-12-01

Results submitted2025-11-24

View on ClinicalTrials.gov More SARS-CoV-2 Infection trials

Who can participate

Age range

18 Years

Sex

ALL

See this in plain English?

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