Regular readers of this column are already well aware of the preventive effects of Vitamin D with respect to falls in the elderly, certain cancers, and cardiovascular disease. (My new book, “A Cancer Prevention Guide for the Human Race,†which is scheduled to be published in August, 2010, contains an exciting and comprehensive update on the role of Vitamin D in cancer prevention.) Now, a newly published research study, which appears in the current issue of the Archives of Internal Medicine, has linked low Vitamin D levels in the blood with an increased risk of cognitive decline and dementia in adults over the age of 65.
A total of 858 adults at or over the age of 65 participated in this prospective public health study, which was conducted over a period of 7 years. All of these study volunteers underwent extensive evaluation of their cognitive function, using validated, standardized tests, when they entered into the study. All patients also underwent testing of their blood for Vitamin D levels. This extensive evaluation and testing was then repeated every 3 years during the course of this important clinical research study.
The results of this study indicated that patient volunteers with low Vitamin D levels in the blood (less than 25 nmol/liter), when compared with volunteers with normal blood levels of Vitamin D (75 nmol/liter, or higher), experienced significant declines in their intellectual function over the course of this study. Indeed, the patient volunteers with decreased Vitamin D levels in their blood were as much as 60 percent more likely to experience progressive cognitive decline or dementia over the relatively brief duration of this study, when compared with the patients who had normal levels of Vitamin D in their blood!
The results of this study are very similar to the findings of a similar study, which has just been published in the journal Neurology. In this particular study, an inadequate level of Vitamin D in the blood of elderly men and women was associated with a significantly increased risk of cognitive decline and dementia from all causes, including Alzheimer’s disease and stroke. Moreover, abnormalities of the brain, as detected by MRI scans, were also more commonly observed in patients who were deficient in Vitamin D.
Vitamin D deficiency is very common in older men and women. An estimated 80 percent of people over the age of 65 have inadequate levels of Vitamin D in their blood, while as many as 45 percent of older men and women also have severe Vitamin D deficiency.
The results of these two studies strongly suggest that adequate levels of Vitamin D in the blood may be associated with a significantly reduced risk of aging-associated cognitive decline and dementia in older men and women, in addition to improving muscle strength, decreasing the risk of certain cancers, and decreasing the risk of cardiovascular disease.
Not everyone should take large doses of Vitamin D, however, as the unmonitored use of this potent hormone-like vitamin can cause dangerous elevations in the level of calcium in the blood, as well as calcifications in the soft tissues of the body, kidney failure, pancreatitis, and gastrointestinal ulcers. (Prior to starting Vitamin D supplements, you should certainly discuss the risks and benefits of Vitamin D supplementation with your physician.)
To learn more about the critical role of Vitamin D and the risk of cancer, look for the publication of my new landmark book, “A Cancer Prevention Guide for the Human Race,†in the August of this year.
