Vitamin D deficiency in older adults and its associated factors: a cross-sectional analysis of the Mexican Health and Aging Study.

Vitamin D deficiency was common in older adults from a country with adequate sun exposure. The variables associated with this deficiency provide insight into the next steps needed to characterize older adults with this deficiency and to treat it accordingly.

PURPOSE: The aim of this study was to describe the prevalence of and factors associated with vitamin D deficiency among Mexican older adults.

METHODS: This was a secondary analysis of the last wave of the Mexican Health and Aging Study. Vitamin D levels along with other biomarkers were obtained from a sub-sample of Mexican adults older than 60 years. Prevalence was described by sex and age group, and a multivariate analysis was performed to test the factors associated with this condition.

RESULTS: Data from 1088 adults over the age of 60 years were analyzed. The mean serum vitamin D level was 23.1 ± 8.1 ng/mL and was significantly higher among men than women (25.6 ± 0.6 and 22.8 ± 0.5 ng/mL, respectively; p < 0.001). In total, 37.3% (n = 406) presented with vitamin D deficiency, 65% of whom were women. Low 25-(OH)-vitamin D levels were associated with female sex (OR 1.74, 95% CI 1.59-2.42), current smoking (OR 2.21, 95% CI 1.47-3.39), education (OR 1.1, 95% CI 1.06-1.13), physical activity (OR 1.74, 95% CI 1.31-2.23), and high levels of glycated hemoglobin (OR 1.16, 95% CI 1.07-1.25).

CONCLUSIONS: Vitamin D deficiency was highly prevalent in Mexican older adults and was associated with a number of factors, indicating the multifactorial causality of this deficiency.