33.5.93 - nutrition

A patient with keratinized goosebump-like skin and a keratinized cornea (Bitot's spots) has trouble seeing in the dark. The biochemical deficiency most likely related to loss of vision in the dark is in the

a. absorption of zinc.
b. absorption of alpha-tocopherol.
c. generation of 25-hydroxy-vitamin-D3.
d. gamma-carboxylation of glutamate residues.
e. generation of all-trans retinal.