Association of serum vitamin D with frailty in older Korean adults

Abstract

Objectives: The association between serum levels of vitamin D and frailty in older Korean adults was examined. Study design: Cross-sectional study. Older people living in the community across 10 study centers throughout South Korea. The baseline data (2016–2017) of 2872 participants aged 70–84 years in the Korean Frailty and Aging Cohort Study were evaluated. Main outcome measures: Serum vitamin D level was assessed with an electro-chemiluminescence immunoassay. Frailty was defined using Fried's frailty index. A multinomial logistic regression analysis was used to examine the association between serum levels of vitamin D and frailty. Results: The percentages of those with serum vitamin D levels of <25 nmol/L, 25−49 nmol/L, 50−74 nmol/L, and ≥75 nmol/L were 4.1 %, 37.0 %, 37.8 %, and 21.0 %, respectively. The prevalence of frailty was 9.7 %. Those with lower serum vitamin D levels, compared with ≥75 nmol/L, tended to have higher odds of being frail than being non-frail (OR: 1.58, 95 % CI: 1.05–2.39 for 50−74 nmol/L; OR: 1.49, 95 % CI: 0.98–2.26 for 25−49 nmol/L; OR: 1.37, 95 % CI: 0.65–2.88 for <25 nmol/L). Among the components of frailty, low grip strength was significantly associated with lower serum levels of vitamin D. Conclusions: Low serum levels of vitamin D are associated with an increased likelihood of frailty in community-dwelling older adults, suggesting a potentially protective role of vitamin D against frailty. © 2020 Elsevier B.V.