VITAMIN D INSUFFICIENCY IN ELDERLY ADULTS LIVING IN BUENOS AIRES

Abstract

The urban population is prone to hypovitaminosis D due to the type of habitat and indoors lifestyle.

Elderly people are susceptible to hypovitaminosis D. Furthermore, low-income elderly subjects

have been identified as a target population. The aim of this study was to investigate serum levels of

25(OH)D in winter, and determinant factors in an aged population living at home, in a large

overpopulated city. We studied healthy people aged 71.5±5.4 years (113 women and 56 men) living

in the city of Buenos Aires (34° S) at the end of winter. Exposure to sunlight, habitat, type of

clothing worn in summer, vitamin D-rich food (D-food) intake and socioeconomic status were

assessed by specific questionnaires.We measured serum calcium, parathormone, markers of bone

turnover and 25OHD. Mean circulating 25(OH)D levels were 17.9±0.64 ng/ml. Only 51% of

subjects received sunlight exposure; 63% consumed vitamin D-rich foods. 25(OH)D levels were

higher in men and in subjects with more than 3.5 hr/week of sun exposure,who ate vitamin D-rich

foods three times/week or more, lived in a house, and those who wore light clothes during the

summer. A multivariate linear regression model showed that sex, sunlight exposure and vitamin D-

rich food intake are predictors of 25(OH)D serum levels. Subjects with low income received less

time of sunlight exposure per week, had poor intake of D- food, and an increased level of

parathormone and bone turnover rate. Serum levels of 25(OH)D were similar in the three

socioeconomic classes, but high-income subjects show a trend toward better vitamin D status.