Philip J. Goscienski, M.D.
October 2010
The torrent of research on vitamin D continues to yield positive and negative results. Positive findings confirm that this nutrient is far more important than we had thought. On the negative side, great numbers of people lack sufficient amounts of vitamin D and suffer needlessly from conditions that are easily treated with this safe and inexpensive supplement.
Finland is a nation whose long winter leaves its population unable to form vitamin D from sunlight during much of the year. In a study that included more than 3,000 men and women over a 29-year period, Finns with the highest levels of vitamin D were 67 percent less likely to develop Parkinson's disease than their countrymen with the lowest levels. Considering that as a whole, the Finnish population tends to have levels of vitamin D that are about half of what is recommended, the impact of vitamin D insufficiency may be greater than the study suggests. What is a high level in Finland may be only a moderate level in Florida.
In 2009 French researchers concluded that there was no clear link between levels of vitamin D and cognitive performance among the elderly but less than a year later they reported that among older women, low levels of the vitamin were indeed associated with impaired thinking.
The evidence that a low level of vitamin D is linked to Alzheimer's disease is not conclusive but it is suggestive. We know that genetic factors influence its development. Obesity and diabetes contribute to dementia in about half of Alzheimer's patients because they distort blood vessels that nourish brain tissue. With such a mix of causative factors in a population that is rapidly becoming older, fatter and diabetic, it won't be easy to sort out what role nutrients such as vitamin D might play.
Parkinson's disease, Alzheimer's disease and senile dementia already tax our medical resources. More than one-half of octogenarians suffer from at least one of these conditions. If the recommended daily intake of vitamin D is increased to at least 1,000 units per day, as many experts strongly suggest, we may eventually make a small dent in the incidence of these lifestyle-destroying conditions.
Natural sunlight is the best source of vitamin D but too many of us cover up, use sunblockers or view the outdoors from behind glass. Vitamin D supplements are safe and inexpensive and they are the best choice for almost everyone.
Philip J. Goscienski, M.D. is the author of Health Secrets of the Stone Age, Better Life Publishers 2005. Contact him at drphil@stoneagedoc.com.