Vitamin D status: a U-shaped relationship for SARS-CoV-2 seropositivity in UK healthcare workers

• Published in: BMJ open respiratory research Vol. 9; no. 1; p. e001258
• Main Authors: Lugg, Sebastian T, Mackay, William R, Faniyi, Aduragbemi A, Faustini, Sian E, Webster, Craig, Duffy, Joanne E, Hewison, Martin, Shields, Adrian M, Parekh, Dhruv, Richter, Alex G, Scott, Aaron, Thickett, David R
• Format: Journal Article
• Language: English
• Published: England British Thoracic Society 01.09.2022; BMJ Publishing Group LTD; BMJ Publishing Group
• Subjects: Age; Binding sites; Body mass index; Chromatography; Comorbidity; Coronaviruses; COVID-19; COVID-19 - epidemiology; Demographics; Ethnicity; Female; Health Personnel; Humans; Immune system; Infections; Male; Mass spectrometry; Medical personnel; Minority & ethnic groups; Mortality; Pandemics; Respiratory Infection; SARS-CoV-2; Scientific imaging; Severe acute respiratory syndrome coronavirus 2; State Medicine; United Kingdom - epidemiology; viral infection; Vitamin D; Vitamin D Deficiency - epidemiology; United Kingdom; United Kingdom > UK; COVID-19; viral infection; respiratory infection
• DOI: 10.1136/bmjresp-2022-001258
• ISSN: 2052-4439

BackgroundThere is increasing evidence that vitamin D (VD) deficiency may increase individuals’ risk of COVID-19 infection and susceptibility. We aimed to determine the relationship between VD deficiency and sufficiency and COVID-19 seropositivity within healthcare workers.MethodsThe study included an observational cohort of healthcare workers who isolated due to COVID-19 symptoms from 12 May to 22 May 2020, from the University Hospitals Birmingham National Health Service Foundation Trust. Data collected included SARS-CoV-2 seroconversion status, serum 25(OH)D3 levels, age, body mass index (BMI), sex, ethnicity, job role and comorbidities. Participants were grouped into four VD categories: (1) Severe VD deficiency (VD<30 nmol/L); (2) VD deficiency (30 nmol/L ≤VD<50 nmol/L); (3) VD insufficiency (50 nmol/L ≤VD<75 nmol/L); (4) VD sufficiency (VD≥75 nmol/L).ResultsWhen VD levels were compared against COVID-19 seropositivity rate, a U-shaped curve was identified. This trend repeated when participants were split into subgroups of age, sex, ethnicity, BMI and comorbidity status. Significant difference was identified in the COVID-19 seropositivity rate between VD groups in the total population and between groups of men and women; black, Asian and minority ethnic (BAME) group; BMI<30 (kg/m2); 0 and +1 comorbidities; the majority of which were differences when the severely VD deficient category were compared with the other groups. A larger proportion of those within the BAME group (vs white ethnicity) were severely VD deficient (p<0.00001). A larger proportion of the 0 comorbidity subgroup were VD deficient in comparison to the 1+ comorbidity subgroup (p=0.046).ConclusionsOur study has shown a U-shaped relationship for COVID-19 seropositivity in UK healthcare workers. Further investigation is required to determine whether high VD levels can have a detrimental effect on susceptibility to COVID-19 infection. Future randomised clinical trials of VD supplementation could potentially identify ‘optimal’ VD levels, allowing for targeted therapeutic treatment for those at risk.