Vitamin D and Dementia


Researchers at the University of Calgary’s Hotchkiss Brain Institute in Canada and the University of Exeter in the UK explored the relationship between vitamin D supplementation and dementia in more than 12,388 participants of the US National Alzheimer’s Coordinating Center, who had a mean age of 71 and were dementia-free when they signed up. Of the group, 37 per cent (4,637) took vitamin D supplements.

In the study, published in Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring, the team found that taking vitamin D was associated with living dementia-free for longer, and they also found 40 per cent fewer dementia diagnoses in the group who took supplements.

University of Exeter. “Taking vitamin D could help prevent dementia: Taking vitamin D supplements may help ward off dementia, according to a new, large-scale study..” ScienceDaily. http://www.sciencedaily.com/releases/2023/03/230301101511.htm (accessed March 1, 2023) — https://www.sciencedaily.com/releases/2023/03/230301101511.htm

Journal Reference:

Maryam Ghahremani, Eric E. Smith, Hung‐Yu Chen, Byron Creese, Zahra Goodarzi, Zahinoor Ismail. Vitamin D supplementation and incident dementia: Effects of sex, APOE , and baseline cognitive status. Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring, 2023; 15 (1) DOI: 10.1002/dad2.12404

More on Vitamin D and Covid-19 – 02.06.22

The records of 1,176 patients admitted between April 2020 and February 2021 to the Galilee Medical Center (GMC) with positive PCR tests were searched for vitamin D levels measured two weeks to two years prior to infection. Patients with vitamin D deficiency (less than 20 ng/mL) were 14 times more likely to have severe or critical case of COVID than those with more than 40 ng/mL. Strikingly, mortality among patients with sufficient vitamin D levels was 2.3%, in contrast to 25.6% in the vitamin D deficient group.

Bar-Ilan University. “Pre-infection deficiency of vitamin D is associated with increased disease severity and mortality among hospitalized COVID-19 patients: Study affirms that sufficient vitamin D levels may positively influence the outcome of infection.” ScienceDaily. http://www.sciencedaily.com/releases/2022/02/220203161135.htm (accessed February 6, 2022).

Links to a few older posts on the same topic.

Vitamin D Treatment and Covid-19 Related Outcomes – Hospital del Mar, Barcelona, Spain

Does Vitamin D Deficiency Raise COVID-19 Risk? – JAMA

Vitamin D Deficiency Is Inversely Associated with COVID-19 Incidence and Disease Severity in Chinese People

More on Vitamin D and Covid-19 Vitamin D and Mortality Risk in People With CVD

Vitamin D Treatment and Covid-19 Related Outcomes – Hospital del Mar, Barcelona, Spain

In patients hospitalized with COVID-19, calcifediol treatment at the time of hospitalization significantly reduced ICU admission and mortality.

Nogués, Xavier and Ovejero, Diana and Quesada-Gomez, J. M. and Bouillon, Roger and Arenas, Dolores and Pascual, Julio and Villar-Garcia, Judith and Rial, Abora and Gimenez-Argente, Carme and Cos, ML. and Rodriguez-Morera, Jaime and Campodarve, Isabel and Guerri-Fernandez, Robert and Pineda-Moncusí, Marta and García-Giralt, Natalia, Calcifediol Treatment and COVID-19-Related Outcomes. Available at SSRN: https://ssrn.com/abstract=3771318 or http://dx.doi.org/10.2139/ssrn.3771318

Preprints are early stage research papers that have not been peer-reviewed. I am not a medical doctor nor a scientist and any comments I have on this topic should not be considered a peer review or medical advice.

Take Vitamin D supplements. Let the experts debate this until the end of time. See Does Vitamin D Deficiency Raise COVID-19 Risk? – JAMA. And as the debate rages, take your vitamins.

Does Vitamin D Deficiency Raise COVID-19 Risk? – JAMA

Despite Fauci’s recommendation and claims by many supplement sellers, conclusions about vitamin D blood levels’ connection to a host of diseases, including infections, cannot be determined because of mixed or sparse evidence, according to a recent report written for the US Preventive Services Task Force, which is updating its recommendation on vitamin D deficiency screening. The draft updated recommendation, like its 2014 predecessor, concludes that the evidence is insufficient to assess the benefits and harms of screening in asymptomatic adults for any reason.

Sorting Out Whether Vitamin D Deficiency Raises COVID-19 Risk — https://jamanetwork.com/journals/jama/fullarticle/2775003

The comments to this JAMA article are as educational as the article itself.

But as the debate rages on, I’ll continue to take 1000iu D3 daily. It can’t hurt.

Vitamin D Deficiency Is Inversely Associated with COVID-19 Incidence and Disease Severity in Chinese People

In the general linear model adjusted for age, sex, comorbidities, and BMI, serum 25(OH)D concentrations were significantly lower among COVID-19 patients than the 2018–2019 controls [ln transformed values of 3.32 ± 0.04 vs. 3.46 ± 0.022 ln (nmol/L), = 0.014]. Multivariable logistic regression showed that male sex (OR: 2.26; 95% CI: 1.06, 4.82), advanced age (≥65 y) (OR: 4.93; 95% CI: 1.44, 16.9), and vitamin D deficiency (<30 nmol/L) (OR: 2.72; 95% CI: 1.23, 6.01) were significantly associated with COVID-19 severity (all < 0.05).

These findings suggested that vitamin D deficiency impacts COVID-19 hospitalization and severity in the Chinese population.

Vitamin D Deficiency Is Inversely Associated with COVID-19 Incidence and Disease Severity in Chinese People — The Journal of Nutrition, Volume 151, Issue 1, January 2021, Pages 98–103, https://doi.org/10.1093/jn/nxaa332

More links are in my last post Vitamin D – What’s Your Level?

I am hoping all of my Chinese relatives read this.

Vitamin D – What’s Your Level?

“Our trends this year are dramatically different than previous years’ in that they’re far less fleeting. COVID-19 is a pandemic that sits on top of another pandemic in the United States of malnutrition and poor long-term health,” remarked Shelby Miller, MS, Natural Grocers’ Manager of Scientific Affairs and Nutrition Education. “Hence, 2021 holds broader trends that focus on improving nutrition to support our own health, as well as the health of our communities and our environment.”

While there are many things in life outside of our control, knowing our vitamin D levels is a simple step we can all take to elevate our health and the health of our families—it is something you can own as a proactive tool to be rooted in health. This unique nutrient plays a critical role in whether or not your immune system functions sufficiently and responds as needed. It is essential for lung health, supporting positive moods, brain function, and cognition, a healthy weight, a healthy pregnancy, children’s health, healthy blood sugar levels, healthy blood pressure, bone health, and muscle tone. Between 40 and 80 percent of American adults are outright deficient in vitamin D, while approximately 90 percent have sub-optimal levels. Achieving optimal levels (between 30 and 50 ng/mL) of vitamin D through supplementation is crucial to experiencing its full range of benefits. Because darker skin hampers the body’s ability to synthesize vitamin D from sunlight, supplementation is especially important for people of color. A national survey reported average serum vitamin D concentrations of 28.1 ng/mL, 21.6 ng/mL, and 16.9 ng/mL in Caucasian, Mexican American, and African American adults aged 20 years and older, respectively. Vitamin D is a nutrient all of us should be focused on, and we all need to know our levels, but this is especially important for those with darker complexions.

SOURCE Natural Grocers by Vitamin Cottage, Inc. — https://investors.naturalgrocers.com/2020-12-03-Natural-Grocers-Predicts-Top-10-Nutrition-Trends-For-2021 — Natural Grocers Predicts Top 10 Nutrition Trends For 2021 Press Release 12.03.20

I have no financial relationship with Natural Grocers nor do I shop at their stores often. We get the company’s sales brochure via Snail Mail and when I read the #1 predicted trend for 2021 was Vitamin D supplementation I had to pass it along (with proper attribution). On a personal note I started supplementing with Vitamin D around 7-8 years ago. I was satisfied with my research and figured this was an easy behavioral change. Besides, Vitamin D supplements were (and still are) cheap and widely available.

The Boss and I share the same personal physician. At my last wellness check she looked me in the eye and said,

“Tell you wife to take a Vitamin D supplement.”

True story. BTW my last level was 38 ng/mL. A few more of my posts on Vitamin D are listed below.

More on Vitamin D and Covid-19

As of this article’s writing, there are over two hundred fifty articles on PubMed about the connection between vitamin D and COVID-19. As the research studies are undergoing, evidence is mounting that adequate vitamin D levels may be a protective factor against COVID-19 infection and severity. Here’s what the research shows.

Is there a role for vitamin D in the treatment of COVID-19? — https://www.kevinmd.com/blog/2020/11/is-there-a-role-for-vitamin-d-in-the-treatment-of-covid-19.html

Yesterday I was going to post a link to an article “Over 80 percent of 200 COVID-19 patients in a hospital in Spain have vitamin D deficiency” when I realized I was unable to access or read the original study. It was late, I was tired, and I didn’t feel like crawling through PubMed to find the study. Well someone out there did the crawling for me. If you follow the link to the original article above you’ll find more links to more research on Vitamin D and Covid-19 like the following:

Evidence suggests that vitamin D supplementation could potentially be effective either in treatment or prevention of coronavirus disease 2019 (Covid‐19). Indeed, several studies and trials have begun to investigate the impact of vitamin D supplementation on patients with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection. In this review, we focus on the potential mechanisms of vitamin D in the pathogenesis of Covid‐19. We consider whether deficiency of vitamin D may be one of the underlying biological factors that could explain the excess mortality seen among non‐Caucasians. We also raise several important questions which need to be addressed to provide a clear picture of the extent to which vitamin D supplementation may benefit patients with Covid‐19, particularly those with underlying risk factors.

Vitamin D and Covid‐19: From potential therapeutic effects to unanswered questions — https://doi.org/10.1002/rmv.2159

A little over a month ago I had my annual wellness check up. The medical nerd in me jotted a list of discussion items I wanted to cover during my visit. After catching up on family and checking off the items on my list I asked my doctor if there was anything else she wanted to talk to me about.

No, your list covered all of the things I wanted to talk about except for one. Tell your wife to start taking a Vitamin D supplement.

True story.

Vitamin D and Calcium Reduce Incidence of Recurrent Vertigo (BPPV)

The multi-center study included 957 people in South Korea with benign paroxysmal positional vertigo who had undergone canalith repositioning maneuvers—head movements that shift displaced calcium carbonate crystals in the inner ear. The intervention group included patients who received 400 IU vitamin D and 500 mg calcium carbonate twice daily for 1 year when their baseline serum vitamin D level was below 20 ng/mL along with patients who had higher baseline levels and took no supplements. An observation group had no baseline testing or interventions.

The supplements significantly reduced the annual vertigo recurrence rate by 24%. There were 0.83 recurrences per 1 person-year in the intervention group compared with 1.10 in the observation group. Patients with greater vitamin D deficiencies at baseline derived the most benefit.

JAMA. 2020;324(16):1599. doi:10.1001/jama.2020.18695 — https://jamanetwork.com/journals/jama/fullarticle/2772275

BPPV = benign paroxysmal positional vertigo. The original study in Neurology and the JAMA summary both use the word “prevent” in their respective titles. I think reduce is a more apt description. Semantics aside a 24% reduction in recurrent BPPV episodes is significant.

And yet another example of nutritional deficiencies underlying another disease.

Vitamin D Hypothesis – A Role in COVID-19 Mortality Rates?

Vitamin D Levels Appear to Play Role in COVID-19 Mortality Rates

By analyzing publicly available patient data from around the globe, Backman and his team discovered a strong correlation between vitamin D levels and cytokine storm — a hyperinflammatory condition caused by an overactive immune system — as well as a correlation between vitamin D deficiency and mortality.

The research is available on medRxiv, a preprint server for health sciences.

The role of vitamin D in the prevention of coronavirus disease 2019 infection and mortality

In conclusion, we found significant crude relationships between vitamin D levels and the number COVID-19 cases and especially the mortality caused by this infection. The most vulnerable group of population for COVID-19, the aging population, is also the one that has the most deficit Vitamin D levels.

Vitamin D has already been shown to protect against acute respiratory infections and it was shown to be safe. It should be advisable to perform dedicated studies about vitamin D levels in COVID-19 patients with different degrees of disease severity.

Many years ago I approached my former personal care physician and asked to have my Vitamin D level checked.

“What the hell for?”

“I would like to know my Vitamin D blood level to see if I need to take a supplement.”

“Just get outside in the sun for around 20 minutes a day.”

“Just order the test.”

And he did.  Less than a week later Doc called me back to let me know I had Vitamin D deficiency.  I’ve been taking a daily supplement since.

Vitamin D deficiency is now recognized as a pandemic. The major cause of vitamin D deficiency is the lack of appreciation that sun exposure in moderation is the major source of vitamin D for most humans. Very few foods naturally contain vitamin D, and foods that are fortified with vitamin D are often inadequate to satisfy either a child’s or an adult’s vitamin D requirement. Vitamin D deficiency causes rickets in children and will precipitate and exacerbate osteopenia, osteoporosis, and fractures in adults. Vitamin D deficiency has been associated with increased risk of common cancers, autoimmune diseases, hypertension, and infectious diseases. A circulating level of 25-hydroxyvitamin D of >75 nmol/L, or 30 ng/mL, is required to maximize vitamin D’s beneficial effects for health. In the absence of adequate sun exposure, at least 800–1000 IU vitamin D3/d may be needed to achieve this in children and adults. Vitamin D2 may be equally effective for maintaining circulating concentrations of 25-hydroxyvitamin D when given in physiologic concentrations.

The American Journal of Clinical Nutrition, Volume 87, Issue 4, April 2008, Pages 1080S–1086S, https://doi.org/10.1093/ajcn/87.4.1080S
Published: 01 April 2008

An interesting hypothesis that needs more research.

Update 05.16.20

Journal Reference:

  1. E. Laird, J. Rhodes, R.A. Kenny. Vitamin D and Inflammation: Potential Implications for Severity of Covid-19. Irish Medical Journal, 2020; 113 (5): P81 [link]

Journal Reference:

  1. Petre Cristian Ilie, Simina Stefanescu, Lee Smith. The role of vitamin D in the prevention of coronavirus disease 2019 infection and mortality. Aging Clinical and Experimental Research, 2020; DOI: 10.1007/s40520-020-01570-8