NEW YORK, Mar 28: Depending on their genes, some Parkinson’s patients may be able to slow their deterioration by taking vitamin D supplements, according to a small study from Japan. Researchers randomly assigned 114 people with Parkinson’s disease to take either vitamin D or a placebo every day for a year and found the neurologic condition didn’t progress as much in those who took the supplements, compared to those who took placebos. But that was only true for people with certain versions of a gene for the vitamin D receptor. (agencies)