Vitamin A vs. Beta Carotene

[SludgeMunkey]

In reading up on various dietary supplements, I see a bit of information that confuses me.

Quite a few manufactures have dumped Vitamin A to prevent toxicity issues in animals and replaced it with beta carotene.

While I understand vitamin A toxicity fairly well, I do not quite understand the connection with beta carotene.

Since the beta carotene is metabolized into vitamin A, isn't there still a chance of vitamin A overdose by proxy? Or is there a difference in absorption of the metabolites resulting from beta carotene?

I am not sure if I am reading a marketing ploy or facts based on valid research.

Any input or suggested reading would be greatly appreciated!

 

[Darkmaverick]

Hi Johnny,

From my understanding, vitamin A is a big umbrella category comprising of various forms of retinol, retinol palmitate or acetate, as well as other forms of retinoid compounds - alpha and beta carotenes, cryptoxanthine etc. Some carotenoids can be converted more effectively into retinol but not others.

The rate of conversion and type of compound formed also differs. There is often competitive assimilation. The absorption rate of provitamin-A carotenoids such as beta-carotene is about half that compared to pure retinol forms.

The production of retinol from provitamins are regulated by the amount of retinol already available in the body. Thus, it is 'safer' to supplement with a provitamin rather than the vitamin itself. The absorption of provitamins also depends greatly on the amount of lipids ingested with the provitamin; lipids increase the uptake of the provitamin.

Not sure if this is the info you needed.

Cheers.

 

[SludgeMunkey]

That is exactly the clarity I was looking for.
thank you!

 

[Lugubris]

Just thought I might add that Vitamin A (retinoic acid form) can block the absorption of Vitamin D. Beta carotene is not effected by this though, which may be a contributing factor to the manufacturers switching. However, products with vitamin D should not be used for most salamanders and newts, they are designed for reptiles, dart frogs, and other high light species which need UV light and/or Vitamin D supplements for proper health. From the research I have done, most salamanders and newts synthesize vitamin D a different way.

Feeding your animals food gut loaded with vegetables high in beta carotene (carrots, romaine lettuce ect...) is always better than artificial supplementation.