Some people here say it’s toxic and we should avoid it at all costs. But I also come across people saying it benefits them. Clever people... I’m confused! Is it something we should be avoiding, or taking?
And then, how much? - The uncomfortable answer to that is: we are all different with different bio-chemical individuality. So no real hard and fast answer.
One reason for taking preformed retinol over beta-carotene would be that it has been found in a study of females that up to 50% of them can't convert beat-carotene into active vitamin A. Additionally calculated from food intake questionares in the US, half its population doesn't reach the RDA for vitamin A (which includes the precursor beta-carotene with the wrong assumption it would always convert).
Lastly, traditional societies alledgedly got multiples of preformed vitamin a from their diet. Just think of the offal most of us nowadays never eat. Some of them:
I think Pamoji's advice is good: if you're truly concerned about your VitA level, do testing and experimentation to optimize. I think that if you're not facing noticeable health problems from VitA deficiency, just follow a healthy diet and not bother with supplements. The same for other nutrients: if you're actually missing something due to dietary restrictions, use supplements, but otherwise they're probably not worth the money or potential risks.
I think that most of the marketing claims of "supplement x will boost your health!" are based on some questionable studies that show a barely measurable difference, if you view the data just the right way.
The way I feel about vitamin A (and I don't know enough about it to be honest) is that if we're eating vitamin A rich foods in a balanced diet and there's no malabsorption issue, then supplementing it could possibly be inadvisable. Perhaps with the exception of a multi-vitamin/mineral tablet once a day if not enough food containing it has been eaten.
Because it's a stored vitamin (in the liver I believe??), too much can be toxic I think. But that's all I know.
Personally I went very slowly repleting my serum retinol levels. Took me about 7 years untill I crossed above 20.000 IU of supplemented preformed vitamin A per day. With that my infrequent psoriasis outbreaks ceased forever since.
Now after 12 years in average with 16.000 IU/d I've reached upper normal of serum levels, and therefore decreased the daily vitamin A dose again. Never experienced any negatives.
I wanted to take some liver capsules to improve my iron. I got scared though, because some people seem to believe (and have posted on this forum) that retinol in any amount is toxic to the body. I guess I was wondering whether there is actually any genuine scientific evidence that vitamin A is harmful (except, obviously, if overdosing). I find it hard to believe that this can be the case, especially considering that chart regarding vitamin A intake in traditional societies.
Good idea to test serum retinol though. I’ll look into that.
There are however scary reports of toxicity on the internet with 100.000 IU/d taken for only a few days. So always act reasonably. Also always consider one might be much more sensitive than anyone else. Therefore better start very low dose and increase slowly.