Vitamin D supplementation worsens Alzheim... - Cure Parkinson's

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Vitamin D supplementation worsens Alzheimer's progression: Animal model and human cohort studies 2022

Bolt_Upright profile image

This is about AD, not PD: Vitamin D supplementation worsens Alzheimer's progression: Animal model and human cohort studies 2022


Vitamin D deficiency has been epidemiologically linked to Alzheimer's disease (AD) and other dementias, but no interventional studies have proved causality. Our previous work revealed that the genomic vitamin D receptor (VDR) is already converted into a non-genomic signaling pathway by forming a complex with p53 in the AD brain. Here, we extend our previous work to assess whether it is beneficial to supplement AD mice and humans with vitamin D. Intriguingly, we first observed that APP/PS1 mice fed a vitamin D-sufficient diet showed significantly lower levels of serum vitamin D, suggesting its deficiency may be a consequence not a cause of AD. Moreover, supplementation of vitamin D led to increased Aβ deposition and exacerbated AD. Mechanistically, vitamin D supplementation did not rescue the genomic VDR/RXR complex but instead enhanced the non-genomic VDR/p53 complex in AD brains. Consistently, our population-based longitudinal study also showed that dementia-free older adults (n = 14,648) taking vitamin D3 supplements for over 146 days/year were 1.8 times more likely to develop dementia than those not taking the supplements. Among those with pre-existing dementia (n = 980), those taking vitamin D3 supplements for over 146 days/year had 2.17 times the risk of mortality than those not taking the supplements. Collectively, these animal model and human cohort studies caution against prolonged use of vitamin D by AD patients."

But then this paper from 2021 says vitamin D helped in rats: Effect of Vitamin D Supplementation on the Progression of Alzheimer’s Disease in Rats: A Mechanistic Approach

I will keep digging.

28 Replies

Reading over in a FB group that it is important to take K2 with vitamin D3. Lots of people looking into this.

Good grief. Between you and p_b. we're not going to be taking anything - except what a doctor prescribes. Art - help.

kevowpd profile image
kevowpd in reply to MBAnderson

Some of us have had (and mentioned) these concerns for quite some time. Not specifically re Vitamin D, but around the notion that something is all reward and no risk simply because no "adverse events" have been noted or becuase it is generally considered safe.

Such concerns are routinely dismissed here.

MBAnderson profile image
MBAnderson in reply to kevowpd

Good point. Our problem is there are conflicting reports on almost everything.

kevowpd profile image
kevowpd in reply to MBAnderson

This will continue until PD is broken up into meaningful subtypes. At the moment it is such a mix of different biologies that the outcome of any given study is heavily dependent on who was studied, which with some exceptions, is random.

park_bear profile image
park_bear in reply to MBAnderson

The only supplement I know of that is generally contraindicated is folate.

B6 should be taken separately from levodopa, and the cheap inactive form can be toxic. Use the P5P version of B6.

The evidence in favor of supplementing vitamins D and K is compelling. From my writing here:

When Good Doctors Prescribe Bad Medicine:

What to do to prevent hip fractures? Per the previous articles in this series, take vitamins K1 & K2, plus vitamin D, and a couple of other essential nutrients.

What vitamins K and D do for you [25(OH)D is Vitamin D] :

"[A] 50 % higher risk of hip fracture was observed in subjects with both low vitamin K1 and 25(OH)D compared with subjects with high vitamin K1 and 25(OH)D (HR 1.50, 95 % CI 1.18–1.90)."

In other words, with high levels of K and D the hip fracture risk is only 67% (1/1.50) of the risk at low levels. In medspeak this is a hazard ratio of .67. Note how the data was framed as the dangers of low levels of vitamins rather than the benefits of high levels.

How about alleged improvement due to Fosamax? According to this meta analysis, the risk ratio for hip fracture, according to some published studies, was .63-.65. For the other bisphosphonates it ranged from .58-.73. Even if these numbers are accurate, you will do as well with vitamins, without the risks.


Let’s compare to Vitamin K:

"[I]ndividuals who increased their intake of [K1] or [K2] during follow-up had a lower risk of cancer (HR: 0.64 and HR: 0.41 respectively) and all-cause mortality (HR: 0.57 and HR: 0.55 respectively) than individuals who decreased or did not change their intake. Also, individuals who increased their intake of dietary [K1] had a lower risk of cardiovascular mortality risk (HR: 0.52) [confidence intervals removed for clarity]"

Increasing your vitamin K, you get a 44% reduction in all-cause mortality risk (HR 0.56) versus 10% with statins (RR .90). Likewise, with vitamin K, you get a 48% reduction in cardiovascular mortality risk (HR .52) versus 13% with statins (RR .87). All without the risking death of muscle fibers, or diabetes. Plus with K you get the reduction in hip fracture risk as well.

Why are statins and bisphosphonates even on the market? Why are doctors not checking everyone’s levels of vitmains D and K?


The original text has links supporting the foregoing claims.


Regarding the study of vitamin D and Alzheimer's, the human part of the study revealed an association, which does not prove causation. Even medical researchers who should have known better have mistaken association for causation. An example:

We have a rat study cited above that showed vitamin D improved cognitive status in an Alzheimer's model. So we have conflicting evidence. I personally am not about to quit vitamin D supplementation.

MBAnderson profile image
MBAnderson in reply to park_bear

I spent the evening looking up vitamin D literature and found all positive reports, but what gives me pause is this is the most recent study and they are quite unequivocal.

They refer only to supplementation. I wonder if their conclusion applies to natural sun light?

MBAnderson profile image
MBAnderson in reply to park_bear

Yesterday in the New England Journal of Medicine.

"VITAL Findings — A Decisive Verdict on Vitamin D Supplementation"

"...VITAL and this ancillary study show that vitamin (D) supplements do not have important health benefits in the general population of older adults, even in those with low 25-hydroxyvitamin D levels."

"Results of analyses from VITAL published in peer-reviewed journals have shown that vitamin D supplementation did not prevent cancer or cardiovascular disease, prevent falls, improve cognitive function, reduce atrial fibrillation, change body composition, reduce migraine frequency, improve stroke outcomes, decrease age-related macular degeneration, or reduce knee pain.5-8

In the ancillary study published in this issue of the Journal, LeBoff and colleagues report that, contrary to expectations, vitamin D3 did not reduce the risk of fractures over a median follow-up of 5.3 years, even in the 20% of the participants taking supplemental calcium at a dose of up to 1200 mg per day. 25-Hydroxyvitamin D is essential for the absorption of calcium in the gut and is produced by nonenzymatic skin conversion of previtamin D with activation of the prohormone by liver and renal hydroxylation."

"The fact that vitamin D had no effect on fractures should put to rest any notion of an important benefit of vitamin D alone to prevent fractures in the larger population. Adding those findings to previous reports from VITAL and other trials showing the lack of an effect for preventing numerous conditions suggests that providers should stop screening for 25-hydroxyvitamin D levels or recommending vitamin D supplements, and people should stop taking vitamin D supplements to prevent major diseases or extend life."

Wow. So we have a study showing that it worsens Alzheimer's and now a study that it does absolutely no good? I have family that have been taking large doses for years (under doctor's care).

park_bear profile image
park_bear in reply to MBAnderson

This is looking like a case of association not being causation. In the video below, Dr. Seheult addresses this issue with respect to vitamin D and Covid. Vitamin D status was associated with Covid outcomes, but vitamin D supplementation was not. He proposes that vitamin D is an indicator of sunlight exposure and that sunlight results in higher levels of melatonin. He presents research to back this up:

In studies I cited above, apparently vitamin K was doing the heavy lifting.

With all that said, I am not giving up vitamin D supplementation. Per Dr. S:

" We recently just published a video here on Medcram that showed that all autoimmune diseases reduced in incidence when vitamin D was given prospectively over a five-year period of time."

Also, it must be of some importance since evolution has varied our skin pigmentation to ensure we get vitamin D at higher latitudes.

Boy did this trip my trigger! D3 is mouse POISON. How can they possibly use a mouse model and equate it to humans?!

Check the active ingredient in D-CON bait. (WHAT IS THE ACTIVE INGREDIENT IN THE D-CON BAIT BLOCK? Cholecalciferol (Vitamin D3) is the active ingredient in d-CON baits. Humans need Vitamin D3, but mice cannot tolerate it.)

Vitamin D3 (native) should be supplemented along with Vit. K2. Vitamin D2 is the synthetic form and is not equivalent.

I've noticed a lot a fear mongering recently with D3 and suspect it is because of it's importance (efficacy) in the FLCCC protocol.

There is a long history of the relationship between neurodegenerative disorders and suboptimal Vitamin D levels.

PD and MS relationships to low Vitamin D levels is well known.

I could go on but don't need to.


I put D-con under hood of my car to get rid of a persistent rat. Bait got eaten but no dead rat. Apparently they have to eat a lot of it in multiple feedings over time.

You don't really know how much D3 is in the D-CON bait. They're in business to sell product, the more you need the greater their profit.

I had some expired liquid D3 in olive oil and put bottle caps full in strategic places - no more mice. And there was no risk for secondary poisoning to our pets. You could even make your own D3 rodent poison.

Nonetheless, these authors should not have used mice (or rats) as surrogates for Vitamin D3 research in humans. What would their results have been if they used monkeys instead?


They also studied it in humans.

"We identified 980 patients diagnosed with dementia who were and were not prescribed calcitriol in the NHIRD and followed them over a 11-year period (2000–2010) (Figure 4a). They were frequency matched for similar distributions in age, gender, and eight comorbidities (Table 2). The dementia patients prescribed a high cumulative dose of calcitriol (>146 capsules of 0.25 mcg per year) were found to have a 2.17-fold increase in risk of death, compared with those not prescribed the drug (Figure 4b and Table S6). "

This wasn't a serious or well controlled study, what was the vitamin D status for study participants?

Severely 25(OH)D deficient (<25 nmol/L) and;

Deficient (≥25 to <50 nmol/L); Compared to participants with sufficient concentrations (≥50 nmol/L).

"high cumulative dose of calcitriol (>146 capsules of 0.25 mcg per year)"

146/365= ~once every 2.5 weeks

0.25mcg Vit D3 is 1000 IU, practically nothing and certainly not enough to be preventive for dementia.

Per the study I cited: The multivariate adjusted hazard ratios for incident Alzheimer disease in participants who were severely 25(OH)D deficient and deficient compared to participants with sufficient concentrations were 2.22 (95% CI: 1.02–4.83) and 1.69 (95% CI: 1.06–2.69). In multivariate adjusted penalized smoothing spline plots, the risk of all-cause dementia and Alzheimer disease markedly increased below a threshold of 50 nmol/L.

Our results confirm that vitamin D deficiency is associated with a substantially increased risk of all-cause dementia and Alzheimer disease.

25(OH)D @ 50 nmol/L is "sufficient" - optimal is the upper end of the range between 50-100 nmol/L.

It's challenging to know how much vit D you're getting from food, it's also hard to OD at 5000 IU/day. It's reasonable to get tested twice a year to know your status.

Personally, I'm erring on the side of caution and increasing my dosage, currently sitting at around 30 nmol/L. Took 100,000 IU on week one/day one, and 5000 IU daily. Then 25,000 IU once a week for 3 weeks/5000 IU daily - then retest.

At 30 nmol/L my PTH is elevated and urine calcium elevated, causing me to chronically form kidney stones. This can't continue. Wouldn't wish this on anyone.



there is an answer....get your supplements from food.....imo....hand tough...

Eat mushrooms 😋

chantrelle, turkey tail, lions mane, .......chicken of the woods, sauteed puffballs, mmmmm delish!

Solvang53 profile image
Solvang53 in reply to beehive23


beehive23 profile image
beehive23 in reply to Solvang53

amanita muscaria.....

For medications all drugs have a 'sweet spot' where too much is as bad as too little. I remember a doctor telling me that a simple way of euthanizing a dog is to feed him a full bottle of D3. At the cellular level too much D3 can cluster around the attachment sites but not actually attach. The same mechanism is used to treat allergy; If you inject massive amounts of ragweed protein the body cannot react to it because the receptors are clogged without being able to bind to the D3. D3 must attach to respiratory cell membrane receptors to trigger the release of histamine. Histamine causes the problems if allergies. That's why people take antihistamines.

Solvang53 profile image
Solvang53 in reply to kaypeeoh

I read somewhere that D3 supplements are rat poison...hee...I use the good old sun for my vit d...then again I live in a very sunny area...

Dr give hubby the 50,000 units once a month years ago when he was first deficient and it used to make him feel bad a few days later. But he now takes it in Hardys in a lower dose and is good

was this study funded by big pharma?... I am leary of all "scientific studies" in which they are

I doubt Big Pharma would fund research into a vitamin or supplement, as there’s no money in it. You can’t patent a vitamin.

agreed....that was my point...vit d bad,,,pharma pills good

As a complete aside apparently red heads can make their own vit D if not exposed to the sun enough. A neat piece of evolution.

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