Objectives: To calculate the prevalence of hypovitaminosis D in subjects aged 85 years old and to study the relationship between some common geriatric evaluation scales and vitamin D status.
Design: Prospective cohort study.
Setting: A community-based study.
Participants: 312 subjects aged 85 years old.
Measurements: Geriatric assessment was based on comorbidity, functional status according to the Barthel Index (BI) and Lawton Index (LI), cognitive status measured by the Spanish version of the Mini-Mental State Examination (MEC), nutritional risk according to the Mini Nutritional Assessment (MNA), and gait using the Tinetti Gait Scale. Serum 25(OH)D concentrations were used to assess vitamin D status. Hypovitaminosis D was considered as < 25 ng/ml and deficiency < 11 ng/ml.
Results: Mean serum 25(OH)D level was 28 ± 30 ng/ml. The prevalence of hypovitaminosis D was 52.5% (38.1% insufficiency and 14.4% deficiency). Men had higher levels than women (32.2 ± 44 vs. 25.2 ± 25 ng/ml; p=0.04). The bivariate analyses identified an association between MNA scores and hypovitaminosis D, and showed that females ande participants with poor BI, Tinetti and MNA scores were associated with deficiency. Logistic regression analysis confirmed a significant association between poor MNA scores and both hypovitaminosis D (p < 0.04, OR 1.066, 95% CI 1.002-1.135) and vitamin D deficiency (p < 0.0001, OR 1.192, 95% CI 1.099-1.293).
Conclusions: More than half the population aged 85 years has a vitamin D deficit and 14.4% show a deficiency. A lower score on the MNA scale is associated with a greater likelihood of having lower vitamin D serum values.