Vitamin D has been all the rage for a few years. Ironically, despite the fact that everyone knows that our bodies create vitamin D in response to sunlight and most of us experience mood changes during the darker months, the high likelihood of a link had not been researched.

A study was just published correcting this blatant neglect and it was a very well designed interventional trial to boot. Over 900 elderly women and men were evaluated for evidence of depression and tested for their vitamin D blood level. They were followed for 6 years. At the end of the study women who had low vitamin D levels at the beginning of the study were twice as likely to develop depression. Low vitamin D males were 1.6 times as likely to become depressed.

Multiple Sclerosis has long been linked to vitamin D, with deficiency likely to make people susceptible and supplementation as an effective treatment. The association between vitamin D and MS is clearly important.

Other recent studies have confirmed links between vitamin D levels and various neurologic diseases, including Alzheimer’s. Sceptic that I am, some of those studies do not prove causation to me. I want to know that blood levels were low before the onset of any symptoms because people who are not well, especially if “not well” includes limitations to their mobility or thinking, will tend to go outside less than other people. Consequently they will have relatively lower vitamin D blood levels.

One recent study of Parkinson’s Disease and vitamin D does, fairly well at least, satisfy my skepticism. Finnish scientists analyzed blood of 3,000 individuals sampled between 1978 and 1980. After 30 years they found that individuals with the lowest levels of vitamin D were three times more likely to have developed Parkinson’s compared to those with the highest levels. As the number those developing Parkinson’s was small and the study was not one where vitamin D was given to healthy people to see whether Parkinson’s was prevented by the intervention with vitamin D, there are still some flaws but not enough to discount the findings. As we have often observed links between various environmental toxins and Parkinson’s and vitamin D helps our bodies clear such toxins, a causative connection is certainly possible. Also, as vitamin D has so very many biological effects, it is certainly possible that it might influence the rate of Parkinson’s and other neurologic disease by other means.

As is perfectly obvious at this point, everyone excepting a very few with a couple of rare disease, should make certain that she/he has good levels of vitamin D . In my opinion that means 50 ng/ml or above.


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Michael Carlston, MD is an internationally recognized authority in the integration of conventional and complementary medicine in clinical practice, as well as medical education, research and organizational consulting. Practicing in Santa Rosa, California, Dr. Carlston was voted “Best General Physician In Sonoma County, California” by readers of the Sonoma County Independent newspaper and also named one of the outstanding physicians in the Bay Area by San Francisco Focus Magazine. With 30+ years in private practice, his expertise is in nutrition, homeopathy and sports medicine.

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