Specific into the cat's metabolism is the inability to convert carotenoids to vitamin A; incapability to synthesise ample vitamin D; incapacity to synthesise niacin from tryptophan, incapacity to synthesise cysteine, citrulline, and methionine; and an intolerance to glutamic acid.[15] This unique recipe derives the bulk of its protein from beef, https://www.petskyonline.com/reptile-supplies/