8 replies to this topic

[Mind]

Vitamin A?

[PWAIN]

Are we talking carotenoids here? Not interested in actual Vitamin A, just a good selection of carotenoids.Which one would be included?

[pamojja]

Conversely, I'm more interested in some preformed retinol, since a large percentage can't convert carotenes sufficiently.

[Mind]

I see the conditional statements here. That is good. We can discuss the form of Vitamin A in the "Forms" area when I get it up and running. In Vimmortal 1.0 it was 69% DV and it was retinol and mixed caretenoids. I would suggest this route again.

[hbar]

Retinol and mixed carotenoids would be my vote as well.

[MrHappy]

Ditto.

[Mind]

Over here it was mentioned that all supplemental carotenoids have been linked with increased cancer. Has anyone else read of this? Does anyone know of some recent publications in regards to this? Most vegetarians get an order of magnitude more than RDA of vitamin A/carotenoids in their daily diet, yet I don't think they have an increased rate of cancer.

[e Volution]

Conversely, I'm more interested in some preformed retinol, since a large percentage can't convert carotenes sufficiently.

+1

[niner]

Over here it was mentioned that all supplemental carotenoids have been linked with increased cancer. Has anyone else read of this? Does anyone know of some recent publications in regards to this? Most vegetarians get an order of magnitude more than RDA of vitamin A/carotenoids in their daily diet, yet I don't think they have an increased rate of cancer.

The cancer links are mostly connected with supplemental carotenoids, as opposed to dietary. That may be due to unnatural amounts, to different chemical forms, to matrix effects, or some combination of the above. However, looking at what I think were primarily dietary sources, or a mix of diet and supplements, were the following: a recent paper looked at ~4000 men, and linked serum levels of lycopene (yeah, you heard that right) to higher odds of prostate cancer, while serum levels of vitamin A and alpha carotene were associated with lower odds. Another paper linked lutein, zeaxanthin, and beta cryptoxanthin to higher levels of non-melanoma skin cancer. A possible confounder in the prostate case could be higher risk men who were trying to increase their lycopene levels due to the relatively long-held belief that lycopene was protective in prostate cancer. Or maybe they were really raising their risk. 4000 guys is a big study. It's complicated. As for the skin cancer case, lutein is also photoprotective and cosmetically improves skin. I feel like this area is unsettled, and would prefer to err on the side of lower doses, at least. I'd like to see some retinol/retinyl esters, and a small amount of mixed carotenoids.