Hypovitaminosis D associated to low sun exposure in the population over 64 years old

BACKGROUND AND OBJECTIVE: To identify the factors related to hypovitaminosis D in the population over 64 years of age without known risk factors of hypovitaminosis D. SUBJECTS AND METHOD: It was a cross-sectional population study in individuals over 64 year-old attending basic healthcare areas in our hospital's area of reference. A survey was conducted to assess various items (functional capacity, exposure to sun, walks, eating habits). Blood samples taken from each participant were analyzed. RESULTS: A total of 239 individuals -mean age (standard deviation): 72 (5.4) years- were evaluated. 95% of the participants scored > 90 on the Barthel index. Mean serum 25-hydroxyvitamin D3 -25(OH)D3- concentration was 17 (7.5) ng/ml and intact parathormone was 60 (26 pg/ml). The prevalence of hypovitaminosis D was 87%, including 70.3% with insufficiency (25(OH)D 3 between 11 and 25 ng/ml) and 16.7% with deficiency (25(OH)D 3 ≤ 10 ng/ml). The intake of vitamin D and calcium were below recommended levels. The principal source of vitamin D was oily fish. Participants with deficiency scored lower on the Barthel index, had a higher mean age, lived in flats, had less exposure to sun, and used to walk less in sun-hours. Higher levels of alkaline phosphatase and intact parathormone were found in participants with deficiency. The variables independently and significantly associated with vitamin D deficiency were a Barthel score ≤ 90, scant exposure to sun and living in a flat. CONCLUSIONS: There is a high prevalence of hypovitaminosis D in the population aged over 64 years in our area, which is associated with lower functional capacity, scant exposure to sun and living in flats.