Parkinson’s Disease Linked to Vitamin D Deficiency

Mahlon R. DeLong, MD
Department of Neurology, Emory University School of Medicine
NIEHS Grant U54ES012068

Fifty–five percent of Parkinson’s disease (PD) patients are insufficient in vitamin D, according to new research findings from an NIEHS-supported study at the Emory University School of Medicine. The number of Parkinson’s patients with vitamin D deficiency was higher than either healthy elderly people in the control group or Alzheimer’s disease patients. This finding adds to the evidence that low vitamin D levels are associated with Parkinson’s disease.

Most Americans get sufficient amounts of vitamin D through exposure to sunlight or by dietary supplements. Vitamin D fortified milk or cereals are a minor source of the vitamin and few foods, such as fatty fish like salmon or tuna, contain substantial amounts of vitamin D. However, the body’s ability to produce vitamin D in response to sun exposure decreases with age making elderly people more at risk for vitamin D deficiency.

Currently it is unclear whether there is a cause and effect relationship between vitamin D and Parkinson’s. The connection could be partly related to the decreased mobility of Parkinson’s patients, which may result in less sun exposure, or that there is a direct link between vitamin D insufficiency and the onset or progression of the disease.

Previous studies have shown that the region of the brain, the subtantia nigra, that produces dopamine and that is most affected by Parkinson’s disease, has high levels of vitamin D receptors, suggesting that vitamin D may be important for the normal function of these cells. Emory doctors are conducting additional research to investigate whether vitamin D insufficiency is a cause or a result of having Parkinson’s. A follow-up study is administering standard or larger doses of vitamin D to Parkinson’s patients to determine if the vitamin supplementation will reduce the severity of their condition.

Citation: Evatt ML, Delong MR, Khazai N, Rosen A, Triche S, Tangpricha V. Prevalence of vitamin D insufficiency in patients with Parkinson disease and Alzheimer disease. Arch Neurol. 2008 Oct;65(10):1348-52.