Vitamin A Causing Alzheimer's

[ddjd]

Not my words but found this in another RP group page;

https://www.karger.com/Article/Pdf/110927

"Chronic consumption of pre-formed vitamin A may be the cause of Alzheimer's. Here is the mechanism: Vitamin A is normally transported in the body by retinol binding protein. Excess consumption of vitamin A (I'm talking amounts even smaller than the government recommendations) leads to free circulating vitamin A which is unbound to retinol binding protein. It is this free vitamin A which is toxic.

Vitamin A is a very unsaturated molecule, even more unsaturated than polyunsatured fats. Unsaturated molecules have double carbon-carbon bonds which are extremely electron rich. Two things can happen here. 1. The electron rich vitamin A donates an electron to O2. This creates superoxide, a radical species, which then goes on to create hydrogen peroxide and peroxynitrite which kill cells. 2. Heavy metals such as iron, aluminum, and copper can accept electrons from the electron rich vitamin A and then donate them to O2 to cause the same cascade. This splits the vitamin A molecule (much like polyunsaturated fats) into toxic lipid peroxide species which cause even more damage. This kills neurons in the brain, particularly in the hippocampus which is responsible for emotion and memory. It has been shown that those people who have Alzheimer's have lower levels of retinol binding protein, making vitamin A even more toxic.

Also, overdosing on vitamin A seems to suppress the production of retinol binding protein in a weird feedback loop that makes the toxicity exponentially worse the more you take. It is possible that we correctly diagnose the neurological issues seen in acute hypervitaminosis A as toxicity and incorrectly diagnose them as a degenerative condition in people who chronically ingest much smaller amounts. The same damage may be occurring but over a much longer timescale. Many foods are fortified with this stuff and it might be wise to rethink this strategy.
I will NEVER consume pre-formed vitamin A in any amount ever again whether it be from food (dairy, eggs, liver, chicken thighs) or supplements. It is much safer to get it from fruits and veggies because the body uses the beta carotene in them to make vitamin A but it only makes as much as it needs. It is impossible to overdose that way."


https://www.karger.com/Article/Pdf/110927

 

[Orion]

Great find, thanks.

 

[Braveheart]

yes, great info...thank you!

 

[FredSonoma]

So this is saying beta carotene is safer than the Vitamin A from liver?

 

[Makrosky]

 

[Ella]

Retinol in milk comes with its own RBP making it safe. The same is true if you eat liver. However, heavy metals like cadmium knock retinol off its RBP protein resulting in the deleterious rxns described in that paper. So you don't want to be a smoker and eating foods that are high in retinol.

It would seem that eating plenty of fruits and vegetables as the safest route. However, being hypothyroid makes the conversion of betacarotene to retinol inefficient. Chris Masterjohn says he has SNPs that makes him a poor converter, which is why he supplements CLO and eats liver.

It would be nice to have a reliable easy test for retinol.

 

[FredSonoma]

Retinol in milk comes with its own RBP making it safe. The same is true if you eat liver. However, heavy metals like cadmium knock retinol off its RBP protein resulting in the deleterious rxns described in that paper. So you don't want to be a smoker and eating foods that are high in retinol.

It would seem that eating plenty of fruits and vegetables as the safest route. However, being hypothyroid makes the conversion of betacarotene to retinol inefficient. Chris Masterjohn says he has SNPs that makes him a poor converter, which is why he supplements CLO and eats liver.

It would be nice to have a reliable easy test for retinol.

does smoking increase cadmium in the body?

 

[Ella]

@FredSonoma Yes it does. We have known this for a very long time.

 

[Amazoniac]

The acute and chronic toxic effects of vitamin A
"esterification process may exist to prevent large increases in retinol and retinoic acid, both of which are known to be potentially toxic forms of vitamin A. Myhre et al (27) performed a meta-analysis, from which they concluded that the ingestion of large amounts of vitamin A as liver or oil-based supplements caused an increase in retinol, retinoic acid, and related retinoids, but not as great an increase as that resulting from the ingestion of comparable doses in water-miscible and emulsified forms. A postprandial increase in serum retinol concentration may be blunted when vitamin A is ingested with either food or ample dietary fat, whereas a significant amount of free (unesterified) retinol may circulate when vitamin A is consumed without dietary fatty acids, which leads to excessive production of retinoic acid (28)."

@Zeus

 

[FredSonoma]

@FredSonoma Yes it does. We have known this for a very long time.

Oh interesting didn't know that, thanks

 

[Ella]

So this is saying beta carotene is safer than the Vitamin A from liver?

Supplementation with betacarotone and retinol has been shown in some studies that it increases cancer rates especially in the lungs of smokers. So the fact that cadmium is high in smokers compared to non-smokers is of interest.

Antioxidants and Cancer Prevention

 

[haidut]

@Zeus

Excessive vitamin A can suppress the thyroid and that can lead to brain issues, but I have yet to see an intervention trial, animal or human, that found neurological issues from retinol or its esters. I posted a few threads that PUFA metabolic byproducts are involved in AD, and also that AD is simply diabetes of the brain. If large doses retinol can be shown to worsen insulin sensitivity then there could be a link but again, all the data so far on vitamin A and AD have been epidemiological.

 

[Amazoniac]

Excessive vitamin A can suppress the thyroid and that can lead to brain issues, but I have yet to see an intervention trial, animal or human, that found neurological issues from retinol or its esters. I posted a few threads that PUFA metabolic byproducts are involved in AD, and also that AD is simply diabetes of the brain. If large doses retinol can be shown to worsen insulin sensitivity then there could be a link but again, all the data so far on vitamin A and AD have been epidemiological.

But what do you think about the different forms having different effects from that quote?

 

[Such_Saturation]

Yeah those 5mg of an unsaturated molecule are sure to wreak havoc oh but make sure you take your GRAMS a day of 6 DOUBLE BONDS krill oil, gotta keep your brain well fed

 

[raypeatclips]

To the people saying great info/great find etc, What are you referring to? Can you see more than the first page of the study? Because that first page doesn't say anything at all, let alone something that would cause me to alter my diet or supplementation habits. Genuine question.

Has the person that said that quote at the start read the full study, or just the first page?

This just doesn't feel correct at all, I don't buy it. From a completely not scientific standpoint, vitamin A, really? Out of all the poisonous chemicals and metals linked to alzheimers disease, vitamin A is the cause? How many people do you know that take vitamin A supplements, or eat liver? Maybe it's different for you guys in the USA that have vitamin A added to milk. The study says 1 out of 2 Americans will have alzheimers by 85, I would be surprised if 50% of the population is eating vitamin A to any sort of extent.

 

[FredSonoma]

Supplementation with betacarotone and retinol has been shown in some studies that it increases cancer rates especially in the lungs of smokers. So the fact that cadmium is high in smokers compared to non-smokers is of interest.

Antioxidants and Cancer Prevention

Oh wow that's crazy, never would have thought that. If this is the real mechanism, some way of getting rid of cadmium would help offset this right? Like say sweating out in a sauna?

 

[Constatine]

So this is saying beta carotene is safer than the Vitamin A from liver?

To the best of my knowledge carotene is much more dangerous than retinol.

 

[TeslaFan]

I think this should be investigated in the light of vitamin E deficiency. Vitamin E guards against potential vitamin A toxicity, and in general against oxidation of unsaturated compounds.

 

[ddjd]

I think this should be investigated in the light of vitamin E deficiency. Vitamin E guards against potential vitamin A toxicity, and in general against oxidation of unsaturated compounds.

unfortunately myself and several others on this forum find it very hard to find a good quality vit e. ive been using health naturas one and it causes all kinds of anxiety, tachycardia etc

 

[ddjd]

Excessive vitamin A can suppress the thyroid and that can lead to brain issues, but I have yet to see an intervention trial, animal or human, that found neurological issues from retinol or its esters. I posted a few threads that PUFA metabolic byproducts are involved in AD, and also that AD is simply diabetes of the brain. If large doses retinol can be shown to worsen insulin sensitivity then there could be a link but again, all the data so far on vitamin A and AD have been epidemiological.

apparantly taking taurine with Vitamin A can stop the toxicity symptomns. have you heard anything like this before haidut?