Low Vitamin D May Raise COVID-19 Hospitalisation Risk

Medscape

a day ago

TOPLINE:
An analysis of over 150,000 participants found that insufficient and deficient levels of vitamin D were associated with an increased risk for COVID-19 hospitalisation but not with the risk for COVID-19 infection; however, no significant associations were found among participants with a prior cancer diagnosis.
METHODOLOGY:
Researchers in London used data from the UK Biobank cohort to assess the association between levels of vitamin D (insufficient and deficient vs normal) and both COVID-19 infection and hospitalisation.
They included a total of 151,543 participants (mean age, 56 years; 53% women), with a subset of 24,400 participants diagnosed with cancer prior to 2019.
Serum vitamin D levels were measured at baseline between 2006 and 2010 (deficiency, < 24 nmol/L; insufficiency, 25-50 nmol/L; and normal, > 50 nmol/L); all had at least one positive COVID-19 polymerase chain reaction test.
Endpoints were first COVID-19 infection (measured using the positive polymerase chain reaction test result) and COVID-19 hospitalisation (measured using hospital admission records).
TAKEAWAY:
Among overall participants, 14% had at least one positive COVID-19 test result, of whom 11% were hospitalised; in the cancer cohort, 11% of participants tested positive for COVID-19 and 14% of them were hospitalised.
Vitamin D insufficiency and deficiency were associated with 19% and 36% higher odds of COVID-19 hospitalisation, respectively, than normal levels of vitamin D (P < .001 for both); however, no association was found between low levels of vitamin D and COVID-19 infection.
Sensitivity analyses showed that among Black and Asian participants, low levels of vitamin D were linked to an increased risk for COVID-19 infection but not to increased hospitalisation rates.
Among the subset of patients with cancer, levels of vitamin D were not significantly associated with COVID-19 outcomes.
IN PRACTICE:
"[The study] results highlight the complex role of VitD [vitamin D] in COVID-19 outcomes and the varying impact it has across different population subgroups," the authors wrote.
SOURCE:
This study was led by Maria J. Monroy-Iglesias, Transforming Outcomes through Research, Centre for Cancer, Society, and Public Health, School of Cancer and Pharmaceutical Sciences, King's College London, London, England. It was published online on July 18, 2025, in PLoS One.
LIMITATIONS:
Vitamin D levels were measured at baseline (between 2006 and 2010) over a decade before the COVID-19 pandemic, which may have led to the misclassification of participants' vitamin D status. This study could not account for seasonal variations in vitamin D levels. Subgroup analyses were limited by small sample sizes. The study cohort was not fully representative of the UK population, and potential bias may have arisen from differential access to COVID-19 testing.
DISCLOSURES:
This study did not receive any specific funding. The authors declared having no competing interests.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.