Endocrine Abstracts

One of the most significant health measures implemented during the COVID-19 pandemic has been extended periods of lockdown. Vitamin D is essential for many biological functions including pregnancy and bone health and modulate the immune system. Many studies also suggested a beneficial effect of replenished stores of vitamin D (25(OH)D >50 nmol/l) against severe and long term COVID-19 and self-supplementation is recommended by the government. Here we report on the vitamin D status in a cohort of HCW during the 3^rd UK lockdown. Vitamin D metabolites 25(OH)D and 24,25(OH)₂D were measured simultaneously by LCMS and 1,25(OH)₂D was measured by immunoassay on a cohort of HCW in January 2021. Of the 83 female HCW (42.3±10.5 years; 94% white), only 45.8% were 25(OH)D replete, 36.1% were insufficient (25-49 nmol/l) and 18.1.0% were deficient (<25 nmol/l) With 54% having 25(OH)D <50 nmol/l, HCW were recommended to take D3 supplements as per NICE guidance. After 8 weeks, 25(OH)D increased significantly (+32.5 nmol/l on average, P < 0.001). Only 1.2% of HCW were still deficient and 80.7% were now replete. Concomitantly, 24,25(OH)₂D increased significantly (P < 0.001) and 1,25(OH)₂D also increased by 10.2 pmol/l on average (P = 0.003). Serum 25(OH)D concentrations are at their lowest in winter with expected prevalence of deficiency of 10% in Caucasian women. We observed a high proportion of 25(OH)D deficient HCW (18%). Pandemic restrictions in the UK have aggravated the vitamin D status of female healthcare workers which may have caused supplementary health problems including higher pregnancy risks. Stronger recommendations on vitamin D supplementation should be offered to the population and women during episodes of lockdown.