The prevalence of Vitamin D deficiency and effects of ultraviolet light on Vitamin D levels in elderly Turkish population

Vitamin D deficiency is commonly found in the elderly and is associated with osteoporosis and hip fractures. In this study, Vitamin D status of 138 female and 87 male subjects living in old age homes (OAH) and 171 female and 24 male subjects living in own homes (OH) from Central Anatolia were assessed. A questionnaire was applied to collect information about wearing features and degree of sunlight exposure and benefiting from ultraviolet index calculated (BFUI). We have found Vitamin D deficiency in 33.4% among our subjects. Also, 40.1% of subjects living in OAH (54.1% of females and 18.4% of males) and 24.4% of subjects living in OH (27.9% of females and 4.2% of males) were Vitamin D deficient. Vitamin D deficiency was significantly higher in subjects living in OAH than subjects living in OH (P=0.001) and also higher in females than males (40.7% versus 15.3%, P<0.001). Subjects with Vitamin D deficiency were older (P<0.001), BFUI was lower (P<0.001) and parathyroid hormone (PTH) was higher (P<0.001) than those having normal level of 25(OH)D. There was a significant negative correlation between 25(OH)D levels and age (P<0.001, r=−0.248), PTH and 25(OH)D (P=0.004, r=−0.146), and positive correlation between 25(OH)D and BFUI (P<0.001, r=0.340). Vitamin D deficiency is very common in Turkish elderly subjects especially living in OAH and there is a significant low exposure to sunlight among them. Simply by asking clothing habits and exposure to sunlight, we can able to identify risk of Vitamin D insufficiency in elderly subjects.