Sources of carotenes:
(1) fruits and vegetables containing carotenes (mangoes, apricots, carrots, oranges, green vegetables)
(2) beta-carotene dietary supplements
(3) vitamin A supplements
Risk factors:
(1) diabetes mellitus
(2) hypothyroidism
(3) familial disorder
Clinical findings:
(1) There is a yellowish coloration to the skin.
(2) The color is most intense behind the ears, in the nasolabial folds, and on the palms and soles.
(3) The sclera are white.
Vitamin A intoxication does not take place unless the person is taking excessive vitamin A. A patient has only limited conversion of beta-carotene to retinol.
Laboratory findings:
(1) elevated serum carotene level
(2) normal serum total bilirubin (unless concurrent cholestasis)
Differential diagnosis:
(1) jaundice (the sclera are yellow and serum total bilirubin increased).
