Vitamin A (Retinol) Deficiency and Excess
Vitamin A (Retinol) imbalances include syndromes of deficiency and excess.
Vitamin A Deficiency has a number of characteristic clinical findings, including night blindness (nyctalopia), bitot spots, dry scaly skin (xerosis cutis), and keratomalacia (corneal liquefaction).
Vitamin A Excess is more common than deficiency, and chronic hypervitaminosis A is characterized by dry skin, joint pain, pseudotumor cerebri, and hepatomegaly. Acute vitamin A toxicity presents with nausea/vomiting and vertigo. Crucially, vitamin A is teratogenogenic, and prescription of retinol-containing drugs should be carefully considered in sexually-active and pregnant women.
Find Vitamin A Biochemistry and other Vitamins among Pixorize's visual mnemonics for the USMLE Step 1 and NBME shelf exams.