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Vitamin A

16/10/2021 09:20

Bence Gal Szabo

Vitamin A

Why the supplementation of vitamin A is important and dangerous at the same time, and can it be optimized?

Vitamin A (retinol) contained in our body can originate from two sources:
- carotenoids (mainly alfa and beta carotene) contained in our food (mainly in vegetables) are transformed into retinol by the organism.
- Food of animal origin already contain vitamin A (retinol)

Both deficiency and surplus of vitamin A are harmful. Its surplus causes a relative deficiency of vitamin d3 on the receptor level, and so it is harmful (due to which D3 reduces its toxicity). On the other hand, the body transforms carotenoids into retinol only in the required quantity, so no overdosing is possible in this case (although a research test found the supplementation of both vitamin A and beta-carotene harmful; taking them increased the risk of lung cancer for smokers. But in that research synthetic beta carotene was used, and carotenoids are never present in food only in form of beta carotene, there is always at least alfa carotene present, too, so it is not lifelike, and the same problem exists, as in case of another test, where the supplementation of vitamin E was found harmful... it turned out that vitamin E was only present there as alfa-tocopherol, although gamma-tocopherol, for example, is much more efficient in many ways, and tocopherols are always present together in food, so taking vitamin E as only alfa tocopherol is harmful, even if it comes from natural sources, as it distorts the natural tocopherol ratios of the tissue. We take something that is good, but by doing so we reduce something that is even better - so the net impact is negative.)

Getting back to vitamin A... If taken in form of mixed carotenes, there is no risk, you can’t take too much of it, because the body produces only as much retinol as it requires. In form of retinol, however, it can easily overdose. So it would seem obvious that we should take it a form of mixed carotenoids... But without zinc, we cannot transform it in a necessary manner. Well, let’s take zinc, as well, no problem. All right, but some people - for genetic reasons - are not able to produce from carotenoids a sufficient quantity of retinol, even in case of ingesting the appropriate quantity of zinc. To them, vitamin A is important also in form of retinol!

The liver is practically the only food with relevant vitamin A (retinol) content. 100g liver contains approximately 20 thousand NE vitamin A (between 10 and 80 thousand NE). Our body requires 2 to 8 thousand NE retinol on daily basis. Both lower and higher quantity is harmful. This means that eating liver at least once a week will eliminate the risk of vitamin A deficiency, but eating liver 2 to 3 times a week plus taking 5000 NE retinol per day (e.g. with multivitamin) could be too much... would be optimal for those not eating liver.

Because of the above Multivitamin and Prenatal Multivitamin contain 5000 NE so-called vitamin A equivalent, half of which, 2500 NE comes from mixed carotenoids, from RSPO-qualified (i.e. orangutan-friendly) carotenoids extracted from red palm fruit (mainly alfa, beta and gamma carotenoids, but also other carotenoids and lycopene, although it is not indicated, because it is not transformed into vitamin A by the organism). The other half (2500 NE) comes from retinol. This way those, who do not eat liver, and are unable to transform carotenoids contained in vegetables into retinol, either, still get a sufficient quantity of retinol, while the +2500 NE retinol per day would not be too much for those who eat much liver. The zinc content of the product is abundantly enough to maximize the conversion of retinol from carotenoids, where this is the bottleneck.

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