Associations of 25-Hydroxyvitamin D Status and Supplementation with Adverse Outcomes in Geriatric Rehabilitation Inpatients: RESORT

Objectives: Geriatric rehabilitation inpatients are at a higher risk of 25-hydroxyvitamin D (25(OH)D) deficiency due to poor nutrition and low sunlight exposure. This study aimed to evaluate the prevalence of 25-hydroxyvitamin (25(OH)D) deficiency and supplementation and to investigate their association with adverse health outcomes in geriatric rehabilitation inpatients.Design: Prospective, observational and longitudinal study.Setting and Participants: Geriatric rehabilitation inpatients admitted to geriatric rehabilitation wards at the Royal Melbourne Hospital (Melbourne, Australia) from 16th, October 2017 and discharged until 18th, March 2020 in the REStORing health of acutely unwell adulTs (RESORT) study were included.Methods: 25(OH)D levels measured close to rehabilitation admission were classified as sufficiency (>54 nmol/L), insufficiency (26-54 nmol/L), or deficiency (<26 nmol/L). The usage of vitamin D supplementation was extracted from medication records. Outcomes included incidence of institutionalization at three-month post-discharge, in-hospital mortality and post-discharge mortality.Results: The median age of 1328 geriatric rehabilitation inpatients was 83.9 years (IQR: 78.1-88.7, 58.6% female). 25(OH)D deficiency and insufficiency were present in 8.1% and 26.4% of inpatients, respectively; 74.2% used vitamin D supplementation. 25(OH)D deficiency was associated with higher odds of institutionalization (odds ratio (OR): 1.88, 95% confidence interval (CI): 1.14-3.11), in-hospital mortality (OR: 3.30, 95% CI: 1.54-7.07) and higher risks of one-year mortality (hazard ratio (HR): 1.77, 95% CI: 1.17-2.69) compared to 25(OH)D sufficiency but not with three-month mortality. 25(OH)D insufficiency was not associated with outcomes. Patients who did not use supplementation and had 25(OH)D insufficiency or deficiency had significantly higher in-hospital mortality compared to those who used supplementation.Conclusions: Among geriatric rehabilitation inpatients, 25(OH) D deficiency was associated with institutionalization, in-hospital mortality and one-year mortality. Attention to monitor the vitamin D status is of upmost importance during hospitalization.