Predictors of hip fractures and mortality in long-term care homes in Saskatchewan: Does vitamin D supplementation play a role?

High rates of hip fracture (HF) in long-term care (LTC) lead to increased hospitalization and greater risk of death. Supplementation of residents with vitamin D3 (vitD) has been recommended, but may be infrequently acted upon. Using a prospective cohort design, we explored use of vitD at doses ≥800 IU for hip fractures (HF) and for mortality among permanent LTC residents in Saskatchewan between 2008 and 2012, using provincial administrative health databases (N = 23178). We used stepwise backward regression with Cox proportional hazard multivariate analysis for time to first HF or to death upon entry into LTC (excluding the first three months), the association of daily vitD (determined during the first three months), age, sex, age*sex interaction, prior HF, osteoporosis diagnosis and Charlson Comormidity Score (CCS) was determined. Users of VitD were more likely older, women and those with previous HF. For HF, no significant impact of vitD or CCS was found. Models for mortality, stratified by sex, showed in women only, that vitD use resulted in a significant inverse association with time to death [HR (0.91(0.87-0.96)]; for men it was 0.94(0.88-1.01). The impact of VitD supplementation in LTC deserves further investigation, however, the mechanisms for its effect on mortality remain unclear.