Bone Density, Vitamin D Nutrition, and Parathyroid Hormone Levels in Women with Dementia

Abstract

OBJECTIVE: To determine whether patients with dementia have reduced bone mass, altered vitamin D, or parathyroid hormone status. DESIGN: Survey. SETTING: University hospital outpatient department. PARTICIPANTS: Twenty women with DSM‐III‐R mild dementia living in the community were compared with 40 cognitively normal community‐dwelling women, matched for age, who had been recruited as part of studies in elderly twins. MEASUREMENTS: Bone density at the lumbar spine and neck of femur by dual‐energy X‐ray absorptiometry, intact serum PTH, and 25‐hydroxyvitamin D levels. MAIN RESULTS: There was no significant difference in bone density between the subjects with mild dementia and the age‐ and sex‐matched controls. The intact PTH (mean ± SD) in the demented subjects was 4.9 ± 2.1 pmol/L compared with 2.9 ± 1.7 pmol/L in the twin controls (P < .01). The mean 25‐hydroxyvitamin D in the demented subjects was 61 ± 33 nmol/L, whereas it was 90 ± 38 nmol/L in the twin controls (P < .01). CONCLUSIONS: We conclude that there were no significant differences in the bone density of community‐dwelling women with mild dementia compared with normals. However, there were significant differences in parathyroid hormone and vitamin D levels between the two groups, suggesting that there is a high prevalence of subclinical hypovitaminosis D in demented women in the community.