Can Vitamin D Reduce the Burden of COVID-19?

NCT07128069 | Completed DMC

• 1 other identifier: IRB20-0847
• Study Type: interventional
• Target: 2,093
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to compare the risks of COVID-19 in individuals from the Chicagoland area and other communities in the United States randomized to low (400 IU/day) versus moderate (4,000 IU/day) dose vitamin D.

Conditions

COVID-19

Keywords

vitamin D

Outcome Measures

Primary Outcomes (1)

• Time from randomization to first participant-reported COVID-19 infection

  Reported in a post-randomization survey

  From date of randomization to the earliest of either the first participant-reported COVID-19 infection up to and including 365 days after randomization or right censoring up to 365 days after randomization

Other Outcomes (6)

• COVID-19 infection severity as measured by symptoms using a modified Beat COVID-19 instrument (NCT04337762)

  In the first post-randomization survey in which a participant reported COVID-19 infection up to and including 365 days after randomization

• COVID-19 infection severity as measured by hospital admission

  Hospital admissions up to and including 365 days after randomization

• COVID-19 infection severity as measured by hospitalization with ICU admission

  Hospital admissions up to and including 365 days after randomization

Study Arms (2)

Low Dose Vitamin D (400 IU/day)

ACTIVE COMPARATOR

Subjects in this arm will be randomized to receive low dose vitamin D (oral, 400 IU/day) for 12 continuous months

Dietary Supplement: Vitamin D 400IU

Moderate Dose Vitamin D (4000 IU/day)

ACTIVE COMPARATOR

Subjects in this arm will be randomized to receive moderate dose vitamin D (oral, 4000 IU/day) for 12 continuous months

Dietary Supplement: Vitamin D 4000IU

Interventions

Vitamin D 400IU DIETARY_SUPPLEMENT

Low dose vitamin D (400 IU/day)

Also known as: Vitamin D3

Low Dose Vitamin D (400 IU/day)

Vitamin D 4000IU DIETARY_SUPPLEMENT

Moderate dose vitamin D (4000 IU/day)

Also known as: Vitamin D3

Moderate Dose Vitamin D (4000 IU/day)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Subjects are able to participate if they:
• Are 18 years or older.
• Live in the United States.
• 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 12-month study period.
• Are willing to complete self-report measures at 5 time points over the course of 12 months by completing a 15-minute survey at intake via web and 10-minute web-based follow-up surveys.

You may not qualify if:

• Subjects are excluded from study participation if they:
• Report being pregnant, planning to become pregnant, and/or report breastfeeding during the study period.
• Report a history of chronic kidney disease, including a history of abnormal GFR and/or creatinine.
• Report a history of hyperparathyroidism.
• Report a history of increased falls.
• Report a history of hypercalcemia.
• Report a history of gastrointestinal absorptive disorders, including having undergone bariatric surgery.
• Report a history of kidney stones (1 in past year or 2 in lifetime).
• Report already taking more than 400 IU of vitamin D daily as recommended by their health care provider, excluding multivitamins and excluding supplements that include vitamin D and calcium together.
• Report taking D2.
• Report a history of sarcoidosis.

Sponsors & Collaborators

• University of Chicago: lead
• Cures Within Reach: collaborator

Study Sites (1)

University of Chicago

Chicago, Illinois, 60637, United States

Location

MeSH Terms

Conditions

COVID-19

Interventions

Vitamin D; Cholecalciferol

Condition Hierarchy (Ancestors)

Pneumonia, Viral; Pneumonia; Respiratory Tract Infections; Infections; Virus Diseases; Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; RNA Virus Infections; Lung Diseases; Respiratory Tract Diseases

Intervention Hierarchy (Ancestors)

Secosteroids; Steroids; Fused-Ring Compounds; Polycyclic Compounds; Cholestenes; Cholestanes; Sterols; Membrane Lipids; Lipids

Study Officials

• David O Meltzer, MD, PhD

  University of Chicago

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: 2,000-person two-arm, double-blinded randomized controlled trial, with half the subjects randomized to low dose vitamin D (400 IU/day), which will serve as the control group, and half to moderate dose vitamin D (4,000 IU/day)

Study Record Dates

• First Submitted: August 15, 2025
• First Posted: August 17, 2025
• Study Start: December 28, 2020
• Primary Completion: February 15, 2025
• Study Completion: February 15, 2025
• Last Updated: December 2, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR, ANALYTIC CODE
• Time Frame: Data will be available six months after article publication until five years following article publication. The study protocol, SAP, and ICF will be provided to any requesting party. The CSR and analytic code will be provided to any requesting party following publication.
• Access Criteria: Researchers wishing to use the data must prepare a protocol for the use of the data which will be reviewed for methodological soundness and potential human subjects concerns by the study investigators and the UChicago Medicine Institutional Review Board. The study protocol, SAP, ICF, CSR and analytic code will be provided to any requesting party.

Locations

US (1)