Hypovitaminosis D:: high prevalence in ambulatory-attended elderly people from Barcelona, Spain.: Associated factors

BACKGROUND: Hypovitaminosis D is a frequent finding in the elderly of northern countries. In Spain because of high sun irradiation it has been traditionally considered that hypovitaminosis D is not a frequent problem. In this study we have evaluated the prevalence of hypovitaminosis D in the elderly and the associated factors. SUBJECTS AND METHODS: All individuals older than 65 years attending a primary care unit (november 1995 - march 1996) and without any disease modifying vitamin D status were included. The following data were recorded: age, gender, height, weight, white and red cell counts, glycaemia, serum ions, albuminemia, plasma creatinine, creatinine clearance, urinary creatinine and calcium, parathyroid hormone (PTHi), calcidiol and calcitriol. Sun exposure and fish ingestion was also determined by questionnaire. RESULTS: 127 individuals were evaluated (age: (X) over bar [SD] 74.8 [6.4] years; 47 men, 37.0%). Forty-four subjetcs (34.6%; CI 95%: 26.3-42.9%) had calcidiol levels less than or equal to 10 ng/ml, 15 (11.8%; CI 95%: 6.2-17.4%) low values of calcidiol, and 13 (10.2%; CI 95%: 4.9-15.5%) high PTHi values. Subjects with hypovitaminosis D (calcidiol levels less than or equal to 10 ng/ml) were mainly women, older, short stature, had a lower values of body surface, albuminemia, phosphatemia, creatinine clearence, sun exposure and fish intake and higher PTHi levels. In the logistic regression model, hypovitaminosis D was positively associated with age and negatively with sun exposure, albuminemia, height and phosphoremia. CONCLUSIONS: Hypovitaminosis D is a very frequent finding in Spanish elderly people. Its presence is independently associated with age (positively) and sun exposure, serum albumin, height and phosphoremia (negatively).