All of the following statements concerning vitamin A are correct EXCEPT
A) in humans, retinol, retinal and retinoic acid are completely interconvertible
B) the intestinal mucosa can convert beta-carotene to retinol
C) retinol is transported by a specific plasma protein
D) a cis isomer of retinal is involved in the visual process
E) the liver is the main storage site for retinol and retinol esters

Question

Quizplus · Accepted Answer

Retinol, retinal, and retinoic acid can be interconverted in vivo, but the conversion is not complete. A small amount of the intermediate metabolites may be lost due to metabolic processes.

All of the Following Statements Concerning Vitamin a Are Correct