Revisiting vitamin D status and supplementation for in-patients with intellectual and developmental disability in the North of England, UK

Aims and method To re-evaluate vitamin D testing and supplementation among in-patients with intellectual and developmental disability (IDD) and examine any correlates with physical health conditions, including COVID-19. Records of all in-patients between January 2019 and July 2020 ( n = 78) were examined for 25-hydroxyvitamin D (25(OH)D) level, ward area, supplementation status, test seasonality, medication and health status. Results The mean 25(OH)D level for supplemented (800 IU/day) patients was 75 nmol/L (s.d. = 20), compared with 40 nmol/L (s.d. = 19) in the non-supplemented group ( P < 0.001). Thirty-eight percent of those who were in-patients during the first wave of the COVID-19 pandemic developed symptoms, but the small sample size could not establish vitamin D levels as a predictor of outcome. Clinical implications Vitamin D (800 IU/day) supplementation is effective but the adequacy of the nationally recommended dose of 400 IU/day is unclear. Links to COVID-19 merit further research.