In reference to :

I'm also not sure, however, if they meant carotenes, which are often
 misleadingly labeled as vitamin A, or pure vitamin A (retinol)

I think they meant carotenes from carrots, etc.

I'm trying to de-congest my liver using Chinese Bitters, and gold coin
grass, and was advised by Julia Chang that I should eat mostly cooked, warm
foods, and never or rarely raw and especially cold foods.
I steam vegetables in a steamer, and save the liquid which I add to slow
cooker chicken and beef stews. I think this is a fairly good way to retain
nutrients.

She's also recommended that I not eat bananas, tomatoes, or citrus fruits,
because according to her and Chinese medicine, they weaken the spleen.

Joe R.