University of Wisconsin–Madison ⋅ Medical College of Wisconsin

Vitamin D Supplementation During COVID-19 Infection Is Associated With an Unfavorable Impact of Increased Total Number of Organ Systems Involved

Rachel Quint, MD; Joshua Fogel, PhD; Eric Lam, DO; Sandra Gomez Paz, MD; Sofia Rubinstein, MD

WMJ. 2026;125(4):475-481. Published November 1, 2026.

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ABSTRACT

Introduction: Introduction: COVID-19 is a systemic disease that affects multiple organ systems. We investigated the association between vitamin D supplementation and the number of organ systems involved in hospitalized patients with COVID-19.

Methods: This retrospective study included 808 consecutive patients with COVID-19 treated at a tertiary care hospital in the metropolitan New York City area between March 2020 and May 2020. The outcome variable was the total number of involved organ systems, defined as a score reflecting involvement of the respiratory, neurologic, renal, cardiovascular, hepatic, endocrine, musculoskeletal, and hematologic organ systems.

Results: Overall, 249 patients (30.8%) received vitamin D supplementation. The number of organ systems involved was significantly greater among patients who received vitamin D supplementation (mean [SD], 4.7 [1.82]) than among those who did not (mean [SD], 3.5 [1.93]; P < .001). Vitamin D supplementation was significantly associated with an increased number of organ systems involved (B,0.30; SE, 0.11; P = .01).

Conclusions: Vitamin D supplementation was associated with a greater number of involved organ systems among hospitalized patients with COVID-19. Prospective studies, including randomized clinical trials, are needed to confirm this association.


Author affiliations: Department of Medicine, Aurora Health Care, Milwaukee, Wisconsin (Quint); Department of Management, Marketing, and Entrepreneurship, Brooklyn College, Brooklyn, New York (Fogel); Division of Pulmonary and Critical Care Medicine, Department of Medicine, Rutgers New Jersey Medical School, Newark, New Jersey (Lam); Department of Medicine, Nassau University Medical Center, East Meadow, New York (Paz); Division of Nephrology and Hypertension, Department of Medicine, Nassau University Medical Center, East Meadow, New York (Rubinstein).
Corresponding author: Sofia Rubinstein, MD, Nassau University Medical Center, Division of Nephrology and Hypertension, 2201 Hempstead Turnpike, Box 49, East Meadow, NY 11554; email srubinst@numc.edu; ORCID ID 0000-0002-4805-9736
Funding/support: None declared.
Financial disclosures: None declared.
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