Individuals with Parkinson's disease appear more likely to be vitamin D deficient than healthy adults of the same age or patients with Alzheimer's disease, according to a report in the October issue of Archives of Neurology, one of the JAMA/Archives journals.
"Vitamin D is important for maintaining many physiologic functions, and vitamin D deficiency is associated with increased risk of disease," according to background information in the article. "Patients with chronic neurodegenerative diseases frequently have many risk factors for vitamin D insufficiency," including advancing age, obesity, avoidance of sun exposure, residence in northerly latitudes and having darker skin.
Marian L. Evatt, M.D., M.S., and colleagues at the Emory University School of Medicine, Atlanta, compared vitamin D levels of 100 patients with Parkinson's disease to vitamin D levels of 97 Alzheimer's disease patients and 99 healthy individuals matched for age, sex, race, genotype and geographic location.
"Significantly more patients with Parkinson's disease (55 percent) had insufficient vitamin D than did controls (36 percent) or patients with Alzheimer's disease (41 percent)," the authors write. The average vitamin D concentration in the group with Parkinson's disease was considerably lower than the Alzheimer's disease and healthy groups (31.9 nanograms per milliliter vs. 34.8 nanograms per milliliter and 37 nanograms per milliliter, respectively).
"These findings support the previously suggested need for further studies to assess what contribution a low 25(OH)D [a measure of blood vitamin D levels] concentration adds to the risk of developing Parkinson's disease (vs. other neurodegenerative disorders) and to determine whether correction of vitamin D insufficiency and deficiency will improve motor or non-motor symptoms in Parkinson's disease," the authors conclude.
"Finally, the finding of a high incidence of vitamin D deficiency in the Parkinson's disease and other cohorts highlights the importance of routinely checking the level of 25(OH)D, particularly in elderly patients, since deficiency is strongly correlated with a higher incidence of osteoporosis, falls and hip fractures and has been associated with a higher incidence of several forms of cancer and autoimmune disorders."