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 north ern countries. In Spain because of high sun irradiation it has been traditi onally 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 prima ry care unit (november 1995 - march 1996) and without any disease modifying vitamin D status were included. The following data were recorded: age, gen der, height, weight, white and red cell counts, glycaemia, serum ions, albu minemia, plasma creatinine, creatinine clearance, urinary creatinine and ca lcium, parathyroid hormone (PTHi), calcidiol and calcitriol. Sun exposure a nd fish ingestion was also determined by questionnaire. RESULTS: 127 indivi duals 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 le ss than or equal to 10 ng/ml, 15 (11.8%; CI 95%: 6.2-17.4%) low values of c alcidiol, 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 m ainly women, older, short stature, had a lower values of body surface, albu minemia, phosphatemia, creatinine clearence, sun exposure and fish intake a nd higher PTHi levels. In the logistic regression model, hypovitaminosis D was positively associated with age and negatively with sun exposure, albumi nemia, height and phosphoremia. CONCLUSIONS: Hypovitaminosis D is a very frequent finding in Spanish elderl y people. Its presence is independently associated with age (positively) an d sun exposure, serum albumin, height and phosphoremia (negatively).