The effect of prescribing vitamin D analogues and serum vitamin D status on both contracting COVID‐19 and clinical outcomes in kidney dialysis patients'

Vitamin D plays a role in innate immune system activation, and deficiency increases susceptibility to respiratory infections and disease severity including COVID-19. We determined whether vitamin D levels and medications were associated with contracting COVID-19, and disease severity defined by hospitalisation and dialysis patient mortality.We reviewed serum vitamin D levels, and prescription of cholecalciferol and alfacalcidol along with corresponding medical records of adult dialysis patients from a United Kingdom tertiary centre between March 2020 and May 2021. COVID-19 infection was determined by polymerase chain reaction (PCR) results.362 (35%) of 1035 dialysis patients tested PCR positive for COVID-19. COVID-19 positive patients had lower native median vitamin D (65 (39-95) versus 74 (40.5-101) nmol/L (p = .009) despite greater prescription of cholecalciferol (median 20 000 (20000-20 000) versus 20 000 (0-20 000) IU/week), p < .001, but lower prescription of alfacalcidol 0 (0-3.0) versus 2.0 (0.-5.0) ug/week, p < .001. On multivariate logistic regression COVID-19 infection was associated with haemodialysis versus peritoneal dialysis (p < .001), cholecalciferol dose (p < .001) and negatively with alfacalcidol (p < .001). However, serum vitamin D levels and alfacalcidol dosages were not significantly different for those requiring hospitalisation compared to those managed at home, although those who died were prescribed lower alfacalcidol dosages.Dialysis patients who contracted COVID-19 had lower levels of native vitamin D prior to COVID-19 and were prescribed lower dosages of alfacalcidol. However, there was no association between vitamin D status and disease severity. This retrospective observational analysis supports a potential role for vitamin D and susceptibility to COVID-19 infection in dialysis patients.