Temporal Association of Reduced Serum Vitamin D with COVID-19 Infection: Two Single-Institution Case–Control Studies
Gupta et al.
, Temporal Association of Reduced Serum Vitamin D with COVID-19 Infection: Two Single-Institution Case–Control..
, Nutrients, doi:10.3390/nu14132757
Retrospective study of 107 COVID-19 patients with vitamin D levels measured within 180 days before diagnosis, and 203 patients with levels measured after diagnosis, showing lower vitamin D levels for COVID-19 hospitalized patients compared to non-COVID-19 patients, but no significant association between vitamin D levels before infection and cases.
Authors do not analyze the risk of serious outcomes based on pre-infection levels. Intervention studies show minimal benefit for cases, but much greater benefit for serious outcomes. Results are provided only for vitamin D as a continuous variable.
Gupta et al., 2 Jul 2022, USA, peer-reviewed, 4 authors, study period 1 January, 2020 - 30 September, 2020.
email@example.com (corresponding author), firstname.lastname@example.org, email@example.com, firstname.lastname@example.org.
Temporal Association of Reduced Serum Vitamin D
with COVID-19 Infection: Two Single-Institution
Diviya Gupta † , Sahit Menon † , Michael H. Criqui and Bryan K. Sun *
School of Medicine, University of California San Diego, La Jolla, CA 92093, USA; email@example.com (D.G.);
firstname.lastname@example.org (S.M.); email@example.com (M.H.C.)
* Correspondence: firstname.lastname@example.org; Tel.: +1-(858)-534-9418
† These authors contributed equally to this work.
Citation: Gupta, D.; Menon, S.;
Criqui, M.H.; Sun, B.K. Temporal
Association of Reduced Serum
Vitamin D with COVID-19 Infection:
Case–Control Studies. Nutrients 2022,
Abstract: (1) Background: Vitamin D supplementation has been proposed for the prevention and
treatment of COVID-19, but it is not clear if reduced serum vitamin D predisposes individuals
to COVID-19 and/or is a secondary consequence of infection. This study assessed the temporal
association between serum vitamin D and COVID-19 with two single-institution case–control studies
through the University of California San Diego (UCSD) Health System. (2) Methods: This study
included patients who tested positive for COVID-19 from 1 January to 30 September 2020 with serum
25-hydroxy-vitamin D (25(OH)D) measured within 180 days of diagnosis. Patients were separated
based on whether 25(OH)D was measured before (n = 107 cases, 214 controls) or after (n = 203 cases,
406 controls) COVID-19 diagnosis. COVID-19 infection status was the outcome variable in the
pre-diagnosis study, whereas serum 25(OH)D level was the outcome variable in the post-diagnosis
study. (3) Results: Serum 25(OH)D levels were not associated with the odds of subsequent COVID-19
infection (OR 1.0, 95% CI: 1.0 to 1.0, p = 0.98). However, COVID-19-positive individuals had serum
25(OH)D measurements that were 2.7 ng/mL lower than the controls (95% CI: −5.2 to −0.2, p = 0.03).
(4) Conclusions: In our study population, serum 25(OH)D levels were not associated with the risk
of acquiring COVID-19 infection but were reduced in subjects after COVID-19 infection. These
results support the possibility that reduced serum 25(OH)D is a consequence and not a cause of
14, 2757. https://doi.org/10.3390/
Keywords: COVID-19; vitamin D; 25(OH)D; case–control study
Academic Editors: William B. Grant
and Ronan Lordan
Received: 19 June 2022
Accepted: 28 June 2022
Published: 2 July 2022
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