SARS-CoV-2 positivity rates associated with circulating 25-hydroxyvitamin D levels
Authors: Justin K Niles
Martin H Kroll
Caixia Bi
Michael F Holick
Harvey W Kaufman
Journal: PLoS ONE (2020)
Discipline: Multidisciplinary
Keywords: COVID-19; SARS-CoV-2; 25-hydroxyvitamin D; infection rates; retrospective analysis
Affiliations: Medical Informatics, Quest Diagnostics, Secaucus, New Jersey, United States of America., Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America.

Abstract:  Until treatment and vaccine for coronavirus disease-2019 (COVID-19) becomes widely available, other methods of reducing infection rates should be explored. This study used a retrospective, observational analysis of deidentified tests performed at a national clinical laboratory to determine if circulating 25-hydroxyvitamin D (25(OH)D) levels are associated with severe acute respiratory disease coronavirus 2 (SARS-CoV-2) positivity rates. Over 190,000 patients from all 50 states with SARS-CoV-2 results performed mid-March through mid-June, 2020 and matching 25(OH)D results from the preceding 12 months were included. Residential zip code data was required to match with US Census data and perform analyses of race/ethnicity proportions and latitude. A total of 191,779 patients were included (median age, 54 years [interquartile range 40.4-64.7]; 68% female. The SARS-CoV-2 positivity rate was 9.3% (95% C.I. 9.2-9.5%) and the mean seasonally adjusted 25(OH)D was 31.7 (SD 11.7). The SARS-CoV-2 positivity rate was higher in the 39,190 patients with "deficient" 25(OH)D values (&lt;20 ng/mL) (12.5%, 95% C.I. 12.2-12.8%) than in the 27,870 patients with "adequate" values (30-34 ng/mL) (8.1%, 95% C.I. 7.8-8.4%) and the 12,321 patients with values ≥55 ng/mL (5.9%, 95% C.I. 5.5-6.4%). The association between 25(OH)D levels and SARS-CoV-2 positivity was best fitted by the weighted second-order polynomial regression, which indicated strong correlation in the total population (R2 = 0.96) and in analyses stratified by all studied demographic factors. The association between lower SARS-CoV-2 positivity rates and higher circulating 25(OH)D levels remained significant in a multivariable logistic model adjusting for all included demographic factors (adjusted odds ratio 0.984 per ng/mL increment, 95% C.I. 0.983-0.986; p&lt;0.001). SARS-CoV-2 positivity is strongly and inversely associated with circulating 25(OH)D levels, a relationship that persists across latitudes, races/ethnicities, both sexes, and age ranges. Our findings provide impetus to explore the role of vitamin D supplementation in reducing the risk for SARS-CoV-2 infection and COVID-19 disease. 

Retracted: No

PubPeer comments:
 For the extreme positions and the controversies around the last author see the English wikipedia 10.1371 journal.pone.0239252. All other authors work for a company that makes profit from (largely unnecessary) vitamin D measurements, see https: doi.org 10.1136 bmj.e4743 or https: bmjopen.bmj.com content 9 10 e029760 Without adjustment for individual conditions and diseases the study is largely useless due to reverse causation (as basically all cross-sectional studies in vitamin D research https: pubmed.ncbi.nlm.nih.gov 24690624 ) ``` We adjusted for vitamin D seasonality with a model based on a previous 25(OH)D3 study, utilizing Quest Diagnostics results that fit the present study data well ``` is a method that can not be replicated . Unfortunately the authors did not respond to data requests. ``` Data Availability: Data underlying the study cannot be made publicly available due to ethical concerns about patient confidentiality. Data will be made available to qualified researchers on request to HealthTrends@QuestDiagnostics.com ``` ,