Vitamin D & Dementia Risk

Most people, or at least most women of a certain age, know that vitamin D is especially important to us as we get older (women of a certain age, because: increased osteoporosis risk especially for women and especially with untreated menopause, because estrogen and progesterone are also essential for healthy bone turnover*)

^{*Unless you’re a man with typical manly hormones, in which case, testosterone has you covered!}

But while vitamin D is well-known amongst our demographic to be important for bone health (and quite well-known for being relevant to immune health*, too), its effects on some other systems are not so widely understood, and that’s what we’ll talk about today.

^{*See for example: Does Vitamin D Help Against COVID? ← short answer: vitamin D does so many things for your immune system, and/but no, protecting you from COVID is not one of them. However, it may reduce the risk of long COVID, at least.}

First though, a quick vitamin D primer for anyone catching up:

• Vitamin D2 vs Vitamin D3: What You Would Benefit From Knowing
• Vit D + Calcium: Too Much Of A Good Thing? ← this also talks about safe and effective doses, and what goes wrong if you take too much
• How Taking Vitamin D Supplements Can Sabotage Your Vitamin D Levels

So, what’s this about vitamin D and dementia?

Vitamin D vs Tau protein aggregation

There are some well-known blood biomarkers of Alzheimer’s disease pathology, due to the accumulation of harmful proteins in the brain, including α-synuclein, β-amyloid (also called amyloid-β; it’s the exact same protein just written down differently), and tau protein*.

^{*…which just gets written like that instead of using a Greek letter τ, probably to avoid looking like the Greek letter τ that in mathematics denotes the ratio of the circumference to the radius of a circle (so in other words, 2π).}

We talk about this a bit here: New Alzheimer’s Test Makes Diagnoses 94.5% Accurate

Researchers (Dr. Alexa Beiser et al.) did a prospective cohort study, in which 793 adults (average age 39 at the start of the study) had vitamin D levels measured, and then the researchers scanned their brains 16±2 years later, to check on their tau and amyloid-β levels.

You might be wondering about how seriously the participants took their vitamin D levels; 34% of participants had low vitamin D, and only 5% were taking supplements.

Their results, in few words: those who had higher vitamin D levels (>30 g/mL) in midlife, later enjoyed significantly lower tau aggregation, even after adjusting for factors like age, sex, depression, and cardiovascular health.

However, there was no association between vitamin D levels in midlife and amyloid-β levels later on, so vitamin D clearly isn’t a “one thing fixes everything” solution!

Indeed, technically the study does not prove causality outright, but as usual, the researchers are asking for more funding to find out.

You can read their paper for yourself here: Association of Circulating Vitamin D in Midlife With Increased Tau-PET Burden in Dementia-Free Adults

Want to do something about that tau aggregation?

Here’s a very easy way to do it:

Spermine vs Alzheimer’s & Parkinson’s!

Take care!