Most of us know vitamin D as the sunshine vitamin. It can be synthesized in the skin upon exposure to UVB rays from the sun, or obtained through dietary means. While vitamin D undoubtedly plays a role in maintaining strong bones, scientists have recently found a potential link between dementia like Alzheimer’s disease and getting less than the recommended amount of vitamin D. While the mechanisms are still unfolding, two studies in particular suggest why the “sunshine vitamin” could also be dubbed the “memory vitamin”.
A study conducted by researchers at the University of California, Davis found that among individuals with an average age of 76, those who had less than sufficient blood levels of vitamin D experienced cognitive decline at a rate that was two to three times as fast as those who had sufficient vitamin D levels.¹ Another study found that those who were vitamin D deficient had a 51% higher risk of developing dementia, and those with severe deficiencies had a 122% higher risk.²
Vitamin D is incredibly important for our health, yet deficiency is a prevalent public health concern. If you’ve read our previous post, you’ll know that the amount of vitamin D we can synthesize upon sun exposure depends on our age and skin type. The elderly and those with darker skin synthesize less vitamin D than those who are younger and those with lighter skin. This amount also depends on location and time of year.
Different groups of people need different amounts of vitamin D to stay healthy. For instance, both males and females between the ages of 19 and 50 years old should consume 600 IU or 15 micrograms per day. Fish like tuna and sockeye salmon are dietary sources of vitamin D, but even those with well-balanced diets can have difficulty consuming the recommended amount of this important nutrient each day. This is why vitamin D supplementation is recommended by many health professionals.
While the evidence is not absolutely concrete, vitamin D deficiency seems to play a role in the development of Alzheimer’s disease. If you choose to expose your skin to the sun to obtain vitamin D, use QSun to make sure you’re doing so safely. The QSun device will tell you how long you can stay in the sun before developing a sunburn.
- UC Davis Health System. (2015). Low vitamin D among the elderly is associated with significant decline in cognition, dementia. Retrieved January 5, 2017, from http://www.ucdmc.ucdavis.edu/alzheimers/news/news_vitamin_D.html.
- Littlejohns, T. J., Henley, W. E., Lang, I. A., Annweiler, C., Beauchet, O., Chaves, P. H. M., Fried, L., Kestenbaum, B. R., Kuller, L. H., Langa, K. M., Lopez, O. L., Kos, K., Soni, M. and Llewellyn, D. J. (2014). Vitamin D and the risk of dementia and Alzheimer disease. Neurology, 83(10): 920–928. Retrieved January 5, 2017, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4153851/.