Summary

Previous work has pointed to an association between the risk of Parkinson's disease and lowered levels of vitamin D. In a new study, patients with Parkinson's disease are found to be more likely to have a vitamin D deficiency than those with Alzheimer's disease and healthy controls. Therefore, vitamin D levels ought to be checked among older people in case low levels indicate a risk of Parkinson's disease, as well as other health problems. Also, further work is needed to see why low vitamin D increases the risk of Parkinson's disease.

Introduction

Vitamin D is important for health, with deficiency being linked to various forms of cancer, osteoporosis, and heart disease. As well as in various neurodegenerative disorders. Vitamin D deficiency is quite widespread in the population, especially among the elderly and those who are chronically ill. The receptor molecules for this vitamin are widely distributed in the brain, so an adequate level might well be important for brain health. Previous research has concentrated on the role of vitamin D insuffiency in osteoporosis. In the current report, levels of vitamin D in two neurodegenerative disorders - Parkinson's disease and Alzheimer's disease - are compared.

What was done

Researchers from Emory University School of Medicine, Atlanta, USA, compared vitamin D levels among 100 patients with Parkinson's disease with vitamin D levels in 97 patients who had Alzheimer's disease and 99 healthy controls.

What was found

More patients with Parkinson's disease had insufficient vitamin D compared to those with Alzheimer's disease and the healthy controls. The figures were: 55 percent, 41 percent and 36 percent. And average vitamin D concentrations were lower among the Parkinson's group.

What this study means

We already know that patients with a neurodegenerative disease are at risk of vitamin D insufficiency, because of age, obesity, avoidance of the sun. Therefore, the lowered levels of vitamin D in the Parkinson's group compared with the controls were perhaps not unexpected. But the lowered levels of vitamin D in the Parkinson's group compared with the Alzheimer's group are surprising. It may be that the longer duration of Parkinson's disease and its associated mobility problems mean that these patients have lower sun exposure and are more likely to have vitamin D deficiency than those with Alzheimer's disease. The study is not able to show, however, whether vitamin D deficiency is a risk factor for developing Parkinson's disease, or is just a result of having it. Further research is needed, in case increasing vitamin D intake could be a way of avoiding Parkinson's disease. In the meantime, checking older patients for vitamin D deficiency could be a good way of protecting their health status.