Vitamin A Upper Limit

Ron J

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Oct 5, 2016
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I read that excessive vitamin A interferes with the thyroid and that it weakens bones; does anyone know the safe upper limit that can be consumed daily?
 

sladerunner69

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Nope. I don't think ayone knows the exact limit. I would strongly advicse to look for a supplement that is low in unsaturated fats and not amde from fish oil or soybean oil because I think that could be the culprit in your concerns.
 

Pointless

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Ray Peat has said that excess vitamin A can block thyroid. The optimum dose seems to be variable depending on metabolic rate. 4 oz of liver a week is a good start unless dealing with some kind of condition. I take 90,000 Iu/day for acne and I have orange calluses but no other side effects.
 

Travis

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I wouldn't worry about it. Everyone that is not eating junk-food gets plenty of Vitamin A.

Vitamin A seems to control collagen synthesis, and can build-up in the body. I would recommend doing some serious research before taking it. People have died from eating Polar Bear Liver!

A 2-year-old boy had signs and symptoms of chronic hypervitaminosis A. A course of increasing severity led to eventual death. A younger brother later had similar clinical features. Chicken liver spread containing up to 420 IU/g vitamin A was the likely source of intoxication.
Severe hypervitaminosis A in siblings: Evidence of variable tolerance to retinol intake
 
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Ron J

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Sladerunner: Mine has safflower oil from Carlson brand. I thought it may not be enough to cause any negative effects. I also eat liver daily.

Pointless: When I added 15,000 IU from supplement, in addition to some liver daily(probably 21,000 iu), I noticed a reduction in dandruff, but the negative effects on bones are a concern.

Travis: Thanks. I also read that the toxicity is dependent on other vitamins, such as vitamin D. I've been taking 4000 IU daily of vitamin D and I use the Light Year2(2 bulb) UVB lamp about 4 feet away, for 10 minutes(5 front, 5 back) daily. I think I may be doing too much. I used to supplement more before in addition to the lamp.
 
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Braveheart

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I wouldn't worry about it. Everyone that is not eating junk-food gets plenty of Vitamin A.

Vitamin A seems to control collagen synthesis, and can build-up in the body. I would recommend doing some serious research before taking it. People have died from eating Polar Bear Liver!


Severe hypervitaminosis A in siblings: Evidence of variable tolerance to retinol intake
please keep posted on
I wouldn't worry about it. Everyone that is not eating junk-food gets plenty of Vitamin A.



Vitamin A seems to control collagen synthesis, and can build-up in the body. I would recommend doing some serious research before taking it. People have died from eating Polar Bear Liver!


Severe hypervitaminosis A in siblings: Evidence of variable tolerance to retinol intake
Anymore research on A?
 

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