In a study published in September 2015 in JAMA Neurology, researchers demonstrated a signiﬁcant association between vitamin D insufﬁciency and cognitive decline that is speciﬁcally seen in Alzheimer’s disease and dementia.
The results reinforce the importance of identifying vitamin D insufﬁciency among the elderly. Here, low vitamin D levels were associated with signiﬁcantly faster rates of decline in memory and executive function performance.
This study included approximately 400 men and women participating in research at the Alzheimer’s Disease Centre in Sacramento, Calif. The participants had a mean age of 76 and were either cognitively normal, had mild cognitive impairment, or had dementia.
At the start of the study, the participants’ serum vitamin D levels were measured and the results showed that vitamin D deﬁciency and insufﬁciency were prevalent among all participants. Twenty-six percent were found to be deﬁcient while thirty-ﬁve percent were insufﬁcient.
At the 5 year follow-up, vitamin D deﬁcient participants experienced cognitive decline at rates 2-3 times faster than those with sufﬁcient vitamin D levels. The researchers expected to see cognitive decline in individuals with low vitamin D status; however, they did not expect how profoundly vitamin D impacts cognition. There is enough evidence to recommend that health care providers should discuss daily vitamin D supplementation with their elderly patients.
Vitamin D deﬁciency is a common problem that is associated with many health consequences, yet this deﬁciency could easily be addressed. Sun exposure is the ideal source of vitamin D, but for most of us, sunlight itself is not enough; our bodies require us to obtain vitamin D from other sources. Some racial and ethnic groups are at greater risk of low vitamin D because the higher concentration of melanin that makes their skin darker also inhibits vitamin D synthesis. Many people avoid the sun or cover up with protective clothing due to the dangers of overexposure. In addition, most of us spend a great deal of time inside under ﬂuorescent lights and away from natural light. Also, depending on the particular time of year and what latitude you live at, you may not be able to get adequate vitamin D from the sun. In some locations this can be most of the year.
Compliments of Functional Medicine University, www.functionalmedicineuniversity.com
Michael Jurgelewicz, DC, DACBN, DCBCN. www.functionalmedicineuniversity.com.
Charles DeCarli, MD et al. Vitamin D Status and Rates of Cognitive Decline in a Multiethnic Cohort of Older Adults. JAMA Neurology, September 2015 DOI: 10.1001/jamaneurol.2015.2115