New studies show low vitamin D levels may link to cognitive decline.
Think of the health benefits of vitamin D, and you’ll probably think of bone strength. In recent years, however, the evidence that vitamin D affects more than just bones has mounted; cardiovascular disease, cancers, stroke, depression, and metabolic disorders have all been linked to low vitamin D levels. A new review adds cognitive decline and dementia to that list.
Vitamin D insufficiency has been associated with a variety of clinical disorders and chronic diseases, including impaired balance, decreased muscle strength, mood and cognitive dysfunction, autoimmune disorders such as multiple sclerosis and diabetes (types 1 and 2), and certain forms of cancer.
This goes way beyond preventing rickets! It even goes beyond vitamin D as an immune stimulator.
The authors of a new review assessed 37 studies that evaluated vitamin D concentrations and cognitive function. The studies included various populations and age groups, but most included both men and women over 65 years of age. As part of the review, the authors conducted two meta-analyses: one to compare the mean vitamin D concentration between participants with Alzheimer’s disease (AD) and controls and one to compare mean mental status scores between participants with low vitamin D levels and those with higher levels.
The authors report that participants with Alzheimer’s had significantly lower vitamin D concentrations and that mental status scores were higher among participants with higher vitamin D levels. Many factors affect vitamin D concentrations: skin pigmentation, age, genetics, sun exposure, geographic location of the participants, and time of year. Also, cognitive decline and aging may affect vitamin D levels through dietary and behavioral changes. In the brain, vitamin D has protective functions by regulating genes, directing nerve growth factor, controlling neurotransmitters, and clearing amyloid plaques (a hallmark of Alzheimer’s).
A British study, presented at the Alzheimer’s Association’s International Conference in Honolulu (July 2010) showed that older men and women with low levels of vitamin D are nearly four times as likely to have problems with their memory, attention and logic.
A related report, also published July 2010 by some of the same researchers, in the Archives of Internal Medicine had similar results. It reported that older men and women with low levels of vitamin D don’t do as well on tests of reasoning, learning and memory as those with higher levels.
Participants completed interviews about their health history, had medical examinations, provided blood samples and took tests measuring thinking skills at the start of the study and again after three years and six years.
The analysis reveals that compared with participants who had sufficient vitamin D levels, those who were severely deficient experienced a substantial decline in thinking and in executive function—the ability to organize thoughts, make decisions and plan ahead.
Currently, in the United States, 15 mcg of vitamin D daily is recommended for most children and adults. Vitamin D is available in few foods and supplements are available. A fat soluble vitamin, vitamin D is relatively safe, even at high doses, but muscle pain and gastrointestinal upset can result from supplementation. There is no conclusive amount of vitamin D that protects brain heath.
The review, published in the journal Neurology, does not provide new information regarding brain health and vitamin D, but it does provide a comprehensive collection of evidence that vitamin D is, at the very least, associated with a healthy brain. Interventional studies are needed to determine just how much vitamin D guarantees a better brain.
And in case you are wondering: the authors say that the link between vitamin D deficiency and cognitive decline persisted even after adjusting for diet, health and other factors!
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Better get some Multivitamin for men and start taking it, before you forget why you should!