Does Low Vitamin D Status Increase the Risk of Cognitive Decline?
Mild cognitive impairment, the cognitive pathology somewhere between normal aging and dementia, is a feared beginning of a downward path for the aging population. Alzheimer's disease and dementia are two diseases that can be unbearable for both the individual and their loved ones.
Progressive memory loss and cognitive decline can affect the family in many ways; the family can become the caregivers and must support the person affected with many different daily tasks of living. The family may also experience emotional distress and lower quality of living. (Photo via Unsplash)
Cognitive decline, like most diseases, is believed to be caused by a combination of genetics and the environment. Thankfully, there are many preventative measures people can take to reduce risk, such as eating a healthy diet, exercising regularly, continuing to challenge your brain and maintaining optimal vitamin D levels. A very recent meta-analysis of twenty-six studies concluded low vitamin D is a clear risk factor for developing dementia.
Increasingly, people are looking for ways to prevent the cognitive decline that comes with getting older. Vitamin D not only helps regulate gene expression but it simultaneously targets several factors leading to neurodegeneration via immune, antioxidant and anti-ischemic actions, and the regulation of neurotrophic factors, acetylcholine neurotransmitter and even the clearance of beta amyloid. Thus, vitamin D has pervasive effects on both the peripheral and central nervous system. Therefore a mechanism exists to explain how vitamin D deficiency may be involved in a host of neurological diseases such as Alzheimer's, multiple sclerosis, dementia, autism and a dozen others.
New Research on Vitamin D and Cognition
A new study looked at the correlation between vitamin D levels and cognition. In this case, cognition was measured using the Montreal Cognitive Assessment (MoCA). MoCA scores can be anywhere from 0-30 and <25 is considered mild cognitive impairment. Researchers in this study hypothesized that low serum vitamin D levels would be associated with low MoCA scores and they assessed cardiorespiratory fitness (CRF) to confirm it plays a role as well.
The sample consisted of 4,358 patients (n=1193 women, n=1963 men) >55 years of age from the Cooper Clinic in Dallas, Texas. The patients filled out a medical history and received a physical exam and serum blood draw.
What Did the Researchers Find?
The researchers evaluated the participants vitamin D levels at baseline and assessed memory and executive function using the MoCA scores. Serum vitamin D levels below 30 ng/mL were considered low.
The researchers also assessed the participant's physical fitness by measuring CRF, which was defined as the duration of a maximal treadmill exercise test.
The findings suggested a significant association between low levels of vitamin D and low MoCA scores (p < 0.03). Specifically, there was a 26% increased risk of having low MoCA scores with even a moderately low 25(OH)D (<25 ng/mL). In addition, CRF contributed to a reduced chance of having a low MoCA score but, surprisingly, this finding did not reach statistical significance.
This study suggests that testing and supplementation of vitamin D may help prevent cognitive decline with age. Furthermore, adding in aerobic exercise can only help support both physical and mental health among aging individuals.
This study adds to the mounting research on the topic. For example, a randomized controlled trial in the journal of Experimental Gerontology concluded that “visuospatial memory was enhanced with higher doses of vitamin D supplementation.” Another study concluded, “Here for the first time we have demonstrated that a low vitamin D status increased the risk of MCI as well as dementia in this prospective study with a community-based cohort of the elderly.” To read more about this topic, check out our previous blogs here.
Vitamin D Council Recommendations
The Vitamin D Council suggests adults supplement with 5,000-10,000 IU vitamin D3 daily when they are unable to receive safe and sensible sun exposure to try to prevent dementia. Higher doses, such as that used in a randomized controlled trial, showed vitamin D may even help improve cognition. To date, only animal studies have found vitamin D may help established dementia but clinical trials are underway in humans.
A high-quality brand we suggest is BioTech Pharmacal for all your vitamin D supplement needs (use code “VDCBiotech20” for 20% off your order). The Vitamin D Council began recommending BioTech 15 years ago after we thoroughly evaluated their products for the 3 Ps, potency, purity and price. Biotech also sells a range of other high quality inexpensive supplements that may be useful in dementia such as curcumin, resveratrol and omega-3 fatty acids.