For 10 points, name this vitamin that is found in carrots and is important in preventing night blindness.
A metabolite of this vitamin has a 13-cis form that is used to treat acne. A sign of a deficiency of this vitamin is a buildup of keratin plaques known as Bitot spots. Deficiencies of this vitamin include keratomalacia [ker-ah-to- mah-LAY-she-eh], which causes ulcers, and xerophthalmia [zeer-op-THAL-mee-uh]. The absorption of a photon causes this vitamin's namesake aldehyde to isomerize from its 11-cis form to its all-trans form. Along with D, E, and K, this vitamin is fat-soluble. Sometimes known as retinol, this vitamin can be derived from beta-carotene. For 10 points, name this vitamin that is found in carrots and is important in preventing night blindness.
A metabolite of this vitamin has a 13-cis form that is used to treat acne.
Vitamin {A} [accept {retinol} before mentioned]