Taking vitamin D is an important part of any nutritional supplement regimen. Regular doses of the vitamin keep bones healthy, muscles moving smoothly and osteoporosis at bay. Now, though, scientists are saying that people who are just beginning to experience Parkinson’s disease may have insufficient levels of vitamin D.

A study published in the Archives of Neurology found that between 70 percent of early Parkinson’s patients have a vitamin D insufficiency, which is defined as a level below 30 nanograms of the vitamin per milliliter (ng/mL) of blood.

A full-blown deficiency is described by the National Institutes of Health as a level below 15 mg/mL of blood, a state that more than a quarter of the study’s cohort was suffering from.

More than 150 participants were evaluated for their blood-serum vitamin levels. After a period of months, the rates of insufficiency and deficiency dropped to 51 percent and 7 percent, respectively.

The team said that they did not expect vitamin D levels to rise in patients with Parkinson’s. They added that vitamin D insufficiency may be a precursor to, but not a permanent symptom of, the disorder.

Elderly Americans may reduce their risk of developing osteoporosis by taking a daily supplement containing vitamin D and calcium.