Prevalence of Vitamin D Deficiency in Patients With Hip Fracture Seen in an Orthogeriatric Service in Sunny Singapore

Abstract

Vitamin D deficiency is common in older adults in Western countries with seasonal winters, when the amount of sunlight is much reduced. There is a paucity of data on the prevalence of vitamin D deficiency in patients with hip fracture in countries such as Singapore where the climate is predominantly tropical. In this study, our aims were to ascertain the prevalence of vitamin D deficiency and risk factors associated with vitamin D deficiency in hospitalized elderly patients with hip fracture in Singapore. We prospectively studied 485 patients with hip fracture admitted to the orthopedic department over a 1-year period. Nonfragility fractures and younger patients (patients <60 years and those with high-impact injuries) were excluded. Data on patient demographics, comorbidities, functional status, and serum 25-hydroxyvitamin D3 levels were collected. Vitamin D deficiency was defined using Holick classification. Vitamin D levels were available for 412 patients. Vitamin D deficiency was present in 57.5% (n = 237). Prevalence of vitamin D insufficiency was 34.5%, with only 8% of patients having normal vitamin D levels. Univariate analyses showed Malay race and functional factors (being housebound, requiring bathing and dressing assistance) to be associated with vitamin D deficiency. However, only ethnicity and housebound patients were significant in the multivariate model. Vitamin D deficiency and insufficiency are common in patients with hip fracture in Singapore. Vitamin D deficiency was associated with being housebound and those of Malay ethnicity. Clothing habits resulting in reduced sunlight exposure may increase the risk of vitamin D deficiency.