Casey says, “Hi, Chris, in week 24 you mentioned that some people cannot convert beta-carotene into vitamin A at all. How do you recommend testing for that and treating?”
Chris: If you recall, I talked about one of the signs of this being if someone drinks a lot of carrot juice, the palms of their hands turn kind of orange. That’s one of the ways that you can detect it, but actually this is genetically mediated, so you can do 23andMe and you can look at a few genes. It’s kind of hard to do this. Maybe I’ll put them in a chat box and I’ll give you a link to an article which describes it pretty well. These are the genes you want to look at—rs12934922 and rs7501331. If you look at those two genes, you can determine if you have decreased beta-carotene conversion into retinol, and as with most other genetic polymorphisms, the genes don’t tell the full story, but if you’re homozygous for both of those variants that lead to decreased beta-carotene conversion, it’s going to be pretty likely that you’re going to have some issues with that. I’m going to post that article link there.
https://www.geneticlifehacks.com/beta-carotene-conversion-to-vitamin-a/