Vitamin D and it’s relation to cognitive ability has been a long-researched and discussed idea. A topic that concerns the causes of cognitive decline, dementia, and Alzheimer's disease. Recently, a study was published in JAMA Neurology in which a significant association was shown between insufficient levels of vitamin D and cognitive decline as seen in Alzheimer's disease and dementia. It has long been believed that there is a need to identify vitamin D deficiencies. Moreover, this study now reinforces that claim. The study also states that these low vitamin D levels are directly related to significantly faster rates of decline in memory and executive function performance.
The Study
Over 400 men and women with a mean age of 76 were studied at the Alzheimer's Disease Center in Sacramento, CA. Each of the participants had a mild cognitive impairment or dementia. At the start of this study, the vitamin D levels of the participants were measured, showing that all participants had at least a deficiency or an insufficiency of vitamin D, wherein twenty-six percent of the participants were deficient in vitamin D and thirty-five percent had what are considered insufficient levels.
Five years later, a follow-up was conducted on the same participants. The vitamin D deficient participants saw cognitive decline rates 2-3 times faster than participants with sufficient vitamin D levels. While the decline was not unexpected, the rate of decline was a bit of a surprise to the researchers. These results led researchers to suggest that health care providers should recommend vitamin D supplements to all of their elderly patients.
This study also suggests that there are recommended levels of vitamin D that help decrease the risk of dementia. For instance, a threshold of 50 nmol/L was found to be an ideal threshold for prevention of dementia, and the higher the amount of vitamin D, the more likely your risk of dementia is decreased. Those who have daily exposure to sunlight are found to have threshold levels between 50 and 70 nmol/L.
The Importance of Vitamin D
It is important to understand more about Vitamin D to learn how these findings are even possible in the first place. Vitamin D is actually not a vitamin but rather a hormone. It was assigned this name in 1922 because it was the 4th vitamin to be identified (after A, B, and C). It is a group of stecosteroids which are primarily responsible for the intestine’s absorption of calcium, iron, magnesium, phosphate, and zinc. As a hormone, it is synthesized in one location of the body but affects another. As a result of all of these essential roles, those who are vitamin D deficient may risk poor bone health, anemia, arthritis, and osteoporosis, among other physical and mental health issues.
Sources of Vitamin D
Vitamin D deficiency is incredibly common, yet extremely easy to treat. One highly effective source of vitamin D is the sunlight. In the winter, some people find they have issues with their vitamin D levels due to lack of sunlight. Also, during summer, sunscreen can block production of vitamin D in the skin. Sunscreen absorbs or reflects ultraviolet light and prevents much of it from reaching the skin. Sunscreen with a sun protection factor (SPF) of 8 based on the UVB spectrum decreases vitamin D synthetic capacity by 95%, and SPF 15 decreases it by 98%. While sunlight is a excellent source of vitamin D, it still may not be enough, causing us to seek Vitamin D from other sources. Some of the other sources are nutritional supplements of vitamin D3 that can be purchased over the counter. Food sources including milk and cheese, yogurt fortified with vitamin D, cod liver oil, tuna in water, beef or chicken liver, and egg yolks.
It is important to measure your levels of vitamin D to know how aggressively to supplement vitamin D3. While toxicity from excessive Vitamin D is possible, instances are uncommon. Baza Medical uses a very precise test offered by Quest Diagnostics. Standard healthy serum levels of vitamin D by this assay are 30-100 ng/ml.
The Big Idea
This study should encourage those interested in preventing cognitive decline and dementia to have their vitamin D levels checked and take aggressive action to maintain healthy levels throughout the year. Supplementing vitamin D3 is easy and inexpensive. Strategic use of sunscreen rather than total avoidance of sunlight may also be a way to enhance vitamin D. While there are other factors that contribute to mental performance, this is a simple yet effective way to protect yourself and loved ones from the devastating effects of cognitive decline and Alzheimer's disease.
