Sunlight exposure ameliorates osteoporosis and hypovitaminosis in Parkinson's disease. - GreenMedInfo Summary
Amelioration of osteoporosis and hypovitaminosis D by sunlight exposure in Parkinson's disease.
Parkinsonism Relat Disord. 2011 Jan;17(1):22-6. Epub 2010 Nov 2. PMID: 21050796
Department of Neurology, Mitate Hospital, 3237 Yugeta, Tagawa 826-0041, Japan. firstname.lastname@example.org
A high incidence of fractures, particularly of the hip, represents an important problem in patients with Parkinson's disease (PD), who are prone to falls and have osteoporosis. We previously showed that 25-hydroxyvitamin D (25-OHD) deficiency due to sunlight deprivation with compensatory hyperparathyroidism causes reduced bone mineral density (BMD) in elderly patients with PD. The present study was undertaken to address the possibility that sunlight exposure may maintain BMD and reduce the incidence of hip fracture in elderly patients with PD. In a prospective study, PD patients were assigned to regular sunlight exposure (n=162) or usual lifestyle (n=162), and followed for 2 years. BMD of the second metacarpal bone was measured using a computed X-ray densitometer. Incidence of hip fracture in the two patient groups during the 2 year follow-up period was assessed. At baseline, patients of both groups showed vitamin D deficiency due to sunlight deprivation with compensatory hyperparathyroidism. The exposed group patients were exposed to sunlight (3231 min/year). BMD increased by 3.8% in the sunlight-exposed group and decreased by 2.6% in the usual lifestyle group (p<.0001). Serum 25-OHD level increased from 27 nmol/L to 52 nmol/L in the sunlight-exposed group. Eleven patients sustained hip fracture in the normal lifestyle group, and 3 fractures occurred among the sunlight-exposed group (p=.03; odds ratio=2.4). Sunlight exposure can increase the BMD of vitamin D deficient bone by increasing 25-OHD concentration and leads to the prevention of hip fracture.