Vitamin D deficiency linked to neurodegenerative disease.

We know you are likely to be very familiar with vitamin D, a naturally occurring hormone produced by the body in response to sunlight. Among its numerous health attributes, including support of our bone health, vitamin D also has been found to affect key cells of the immune system. And now we are learning too that this basic nutrient in which many of us are often deficient can result in neurodegenerative disease and cognitive issues.

What contributes to deficiencies? Certainly our indoor lifestyles (in front of our many devices), use of sunscreen that while it protects us from the harmful effects of the sun also blocks out absorption of vitamin D from natural light, and diets that make it difficult if not impossible to get even the minimum recommended daily allowance all contribute to deficiency.

Vitamin D and our immune systems.

Some recent and very timely news to note: researchers in Dublin have reported on their findings from a study that shows an increased risk of COVID-19 with concurrent deficiency of vitamin D.  The authors write "There are considerable experimental data showing that vitamin D is important in regulating and suppressing the inflammatory cytokine response of respiratory epithelial cells and macrophages to various pathogens including respiratory viruses.”1  

This doesn’t come as a surprise to us as there is already clear evidence that deficiency of vitamin D is associated in every autoimmune disease including multiple sclerosis and not only is a risk factor for developing this disease, but also may affect its progression. Low vitamin D blood levels are correlated with an increased number of brain lesions and signs of a more active disease state in people with multiple sclerosis.2

The links between vitamin D, dementia and neurodegenerative disease.

Vitamin D deficiency can be related to increased onset of dementia, as vitamin D plays a role in preventing oxidation and inflammation in the body.

According to one meta-analysis conducted last year that reviewed 11 studies on a total of 21,784 participants, there does appear to be a connection between vitamin D deficiency and increased risk of developing dementia and Alzheimer's.3  In another review published in the Journal of Alzheimer's Disease, vitamin D concentrations were found to be "significantly lower" in individuals with Alzheimer's disease and other forms of cognitive impairment.4

As to why vitamin D deficiency might increase one's risk of certain neurodegenerative diseases, it seems that adequate vitamin D levels are associated with a reduction in amyloid beta and phosphorylated tau, two brain proteins that are hallmarks of Alzheimer's. However, more research needs to be done to further solidify the link between vitamin D deficiency and dementia and the mechanisms that drive it. We also infer that since vitamin D is an important regulator of immune health, and given the fact that every neurodegenerative disease is immune-mediated in our environmentally toxic world, it would make sense that a vitamin D deficiency may contribute to neurological disease initiation.

And even more neurological significance to note.

According to related information as well from the Mayo Clinic
-Cognitive health. Early research suggests that vitamin D might play a role in cognitive health. In one small study of adults aged 60 years and older being treated for dementia, researchers found that taking a vitamin D supplement helped improve cognitive function.
-Multiple sclerosis. Research suggests that long-term vitamin D supplementation reduces the risk of multiple sclerosis.

In addition to potentially playing a protective role against age-related brain disorders, vitamin D could help with daily brain functioning. For starters, it might help ease “brain fog,” which describes the decreased ability to remember and think clearly and since vitamin D receptors often appear in the same area of the brain that is responsible for the formation of new memories we can infer too that this nutrient will help in creating these new memories.

We know there is clearly a rising tide of brain disease and dementia. The World Health Organization (WHO) predicts that by 2050, one-fifth of the world’s population will be older than 60 years, with roughly 115 million individuals affected by dementia. These numbers do not account for the additional 16% to 20% of elderly individuals who are estimated to experience mild cognitive impairment, which can begin years before clinical presentation. While we cannot say that every instance of disease can benefit from vitamin D supplementation, we do have enough information now about the benefits to know that it does help support our overall healthy nutritional needs.

How to make sure you have enough vitamin D.

First, make sure your healthcare practitioner regularly checks your vitamin D levels; in our practice we want to see levels between 60 and 80 ng/mL (your physician may have different reference ranges so please consult them for guidance specific to your health needs). Also, you want to make sure you don’t overdo the dose – there are risks albeit rare to high dose vitamin D when blood levels rise above 150 ng/mL. Since the vitamin is stored in body fat and released into the bloodstream slowly, the toxic effects may last for several months even after you stop taking a too-large dosage. Again, this is why it’s best to let your physician be your guide!

But especially in these challenging times, almost all of us just need more vitamin D than we can possibly get from eating the right foods or being outdoors. We typically recommend patients take 5,000 IU of vitamin D3 + K2 (more about this below) once a day; during periods of extreme stress, an infection or MS relapse, we may recommend a higher dose, but for only a short burst of time.

Why D3 + K2 and not just plain vitamin D3?

First, D3 is more effective at improving our vitamin D levels than other forms of this supplement such as plain D or D2. And a growing body of research shows that when it comes to bone health, ensuring optimal intake of vitamin K is a critical piece of the puzzle. New research is focusing on the synergistic relationship between vitamin K (specifically, vitamin K2) and vitamin D3, especially in terms of bone strength and cardiovascular health. A group of naturally occurring and structurally similar, fat-soluble vitamins, vitamin K is essential for the proper utilization of calcium. Through its activation of the protein osteocalcin, vitamin K helps to bind newly absorbed calcium to the mineral matrix in bone. In addition, vitamin K has been found to help maintain bone mineral density by decreasing the activity of osteoclasts, a cell that breaks down the bone matrix. Therefore, vitamin K and vitamin D not only share similar qualities, but they also act in synergy within the body. Ideally, take your supplement with a meal containing some fat to increase its absorption.

It really is difficult if not impossible to get our vitamin D requirement from nutritional sources so talk to your doctor and don’t forget your D3 + K2 - your brain, bones and immune system are counting on it!!  

In health and hope,
Dr. Suzanne Gazda

References:

1 Trinity College Dublin. (2020, May 12). Vitamin D determines severity in COVID-19 so government advice needs to change, experts urge: Researchers point to changes in government advice in Wales, England and Scotland. ScienceDaily. Retrieved July 20, 2020 from www.sciencedaily.com/releases/2020/05/200512134426.htm

2 Louise Saul, Iris Mair, Alasdair Ivens, Pamela Brown, Kay Samuel, John D. M. Campbell, Daniel Y. Soong, Nadine Kamenjarin, Richard J. Mellanby. 1,25-Dihydroxyvitamin D3 Restrains CD4 T Cell Priming Ability of CD11c Dendritic Cells by Upregulating Expression of CD31. Frontiers in Immunology, 2019; 10 DOI: 10.3389/fimmu.2019.00600

3 Chai, B., Gao, F., Wu, R., Dong, T., Gu, C., Lin, Q., & Zhang, Y. (2019). Vitamin D deficiency as a risk factor for dementia and Alzheimer's disease: an updated meta-analysis. BMC neurology, 19(1), 284. https://doi.org/10.1186/s12883-019-1500-6
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6854782/

4 T.J. Littlejohns ; K. Kos ; W.E. Henley ; E. Kuźma ; D.J. Llewellyn (2015): Vitamin D and Dementia. The Journal of Prevention of Alzheimer’s Disease (JPAD). http://dx.doi.org/10.14283/jpad.2015.68
http://www.jpreventionalzheimer.com/1232-vitamin-d-and-dementia.html

5 Mayo Clinic, vitamin D:
https://www.mayoclinic.org/drugs-supplements-vitamin-d/art-20363792

Additional reading:

Rhodes, J.M., Subramanian, S., Laird, E. and Kenny, R.A. (2020), Editorial: low population mortality from COVID‐19 in countries south of latitude 35 degrees North supports vitamin D as a factor determining severity. Aliment Pharmacol Ther, 51: 1434-1437. doi:10.1111/apt.15777
https://onlinelibrary.wiley.com/doi/full/10.1111/apt.15777

Update in Vitamin D in Multiple Sclerosis.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4727614/

Vitamin D and Multiple Sclerosis: A Comprehensive Review
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5990512/

Vitamin D toxicity: A Clinical Perspective.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6158375/