ArticleBMJ open2021
Vitamin D insufficiency in COVID-19 and influenza A, and critical illness survivors: a cross-sectional study.
Article in BMJ open, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 10 papers.
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Who cites it
10 citing papers in PubMed, 18 citations in OpenAlex.
- Aging and Viral Respiratory Infections: Focus on Vitamin D and Microbiota.BioMed research international · 2026Review
- The effects of SARS-CoV-2 on bone homeostasis.Frontiers in endocrinology · 2026Review
- Exploring the Association of Vitamin D and VDR Polymorphisms with Disease Severity in COVID-19 and Influenza.Biomedicines · 2025Article
- Post-Polio Syndrome: Impact of Humoral Immune Deficiencies, Poliovirus Neutralizing Antibodies, Vitamin D Deficiency.Vaccines · 2025Article
- Vitamin D metabolism in critically ill patients with acute kidney injury: a prospective observational study.Critical care (London, England) · 2024Observational
- The Significance of Low Magnesium Levels in COVID-19 Patients.Medicina (Kaunas, Lithuania) · 2023Review
- Endocrine Aspects of ICU-Hospitalized COVID-19 Patients.Journal of personalized medicine · 2022Review
- Vitamin D and COVID-19-Revisited.Journal of internal medicine · 2022Review
- Low serum levels of zinc and 25-hydroxyvitmain D as potential risk factors for COVID-19 susceptibility: a pilot case-control study.European journal of clinical nutrition · 2022Article
- Can vitamin D status influence seroconversion to SARS-COV2 vaccines?Frontiers in immunology · 2022Article
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Authors and funding
24 authors at 10 institutions in 1 country.
Funding
Abstract
objectivesThe steroid hormone vitamin D has roles in immunomodulation and bone health. Insufficiency is associated with susceptibility to respiratory infections. We report 25-hydroxy vitamin D (25(OH)D) measurements in hospitalised people with COVID-19 and influenza A and in survivors of critical illness to test the hypotheses that vitamin D insufficiency scales with illness severity and persists in survivors.
designCross-sectional study. SETTING AND
participantsPlasma was obtained from 295 hospitalised people with COVID-19 (International Severe Acute Respiratory and emerging Infections Consortium (ISARIC)/WHO Clinical Characterization Protocol for Severe Emerging Infections UK study), 93 with influenza A (Mechanisms of Severe Acute Influenza Consortium (MOSAIC) study, during the 2009-2010 H1N1 pandemic) and 139 survivors of non-selected critical illness (prior to the COVID-19 pandemic). Total 25(OH)D was measured by liquid chromatography-tandem mass spectrometry. Free 25(OH)D was measured by ELISA in COVID-19 samples. OUTCOME MEASURES: Receipt of invasive mechanical ventilation (IMV) and in-hospital mortality.
resultsVitamin D insufficiency (total 25(OH)D 25-50 nmol/L) and deficiency (<25 nmol/L) were prevalent in COVID-19 (29.3% and 44.4%, respectively), influenza A (47.3% and 37.6%) and critical illness survivors (30.2% and 56.8%). In COVID-19 and influenza A, total 25(OH)D measured early in illness was lower in patients who received IMV (19.6 vs 31.9 nmol/L (p<0.0001) and 22.9 vs 31.1 nmol/L (p=0.0009), respectively). In COVID-19, biologically active free 25(OH)D correlated with total 25(OH)D and was lower in patients who received IMV, but was not associated with selected circulating inflammatory mediators.
conclusionsVitamin D deficiency/insufficiency was present in majority of hospitalised patients with COVID-19 or influenza A and correlated with severity and persisted in critical illness survivors at concentrations expected to disrupt bone metabolism. These findings support early supplementation trials to determine if insufficiency is causal in progression to severe disease, and investigation of longer-term bone health outcomes.
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