Based on the analyses of previous studies, a recent research article has suggested that further investigation needs to be done into the possible direct or indirect linkages that Vitamin D deficiency has with Alzheimer's disease and vascular dementia.
William B. Grant, PhD of the Sunlight, Nutrition, and Health Research Center (SUNARC), writes that low serum levels of 25-hydroxyvitamin D [25(OH)D] have been associated with increased risk for cardiovascular diseases, diabetes mellitus, depression, dental caries, osteoporosis, and periodontal disease, all of which are either considered risk factors for dementia or have preceded incidence of dementia.
The author points out that a number of studies reported in 2008 that those with higher serum 25(OH)D levels had greatly reduced risk of incidence or death from cardiovascular diseases.
He further writes that several studies have correlated tooth loss with development of cognitive impairment and Alzheimer's disease or vascular dementia.
There are two primary ways that people lose teeth: dental caries and periodontal disease. Both conditions are linked to low vitamin D levels, with induction of human cathelicidin by 1,25-dihydroxyvitamin D being the mechanism.
Grant also underscores that fact that there is refers laboratory evidence for the role of vitamin D in neuroprotection and reducing inflammation, and ample biological evidence to suggest an important role for vitamin D in brain development and function.
He says that these supportive lines of evidence suggest that studies of incidence of dementia with respect to prediagnostic serum 25(OH)D or vitamin D supplementation are warranted.
The researcher adds that given that the elderly are generally vitamin D deficient, and since vitamin D has so many health benefits, those over the age of 60 years should consider having their serum 25(OH)D tested, looking for a level of at least 30 ng/mL but preferably over 40 ng/mL, and supplementing with 1000-2000 IU/day of vitamin D3 or increased time in the sun spring, summer, and fall if below those values.
Writing in the article, Dr. Grant states, "There are established criteria for causality in a biological system. The important criteria include strength of association, consistency of findings, determination of the dose-response relation, an understanding of the mechanisms, and experimental verification.
To date, the evidence includes observational studies supporting a beneficial role of vitamin D in reducing the risk of diseases linked to dementia such as vascular and metabolic diseases, as well as an understanding of the role of vitamin D in reducing the risk of several mechanisms that lead to dementia."
The article has been published in the Journal of Alzheimer's Disease.