A 4 year old boy recently immigrated from a resource limited region is brought to clinic for difficulty seeing at night. His mother says he frequently bumps into furniture when the lights are dim. Examination shows dry conjunctivae with foamy patches on the sclera. Deficiency of which of the following molecules is most likely responsible?
- A)Phylloquinone, a clotting factor cofactor
- B)Thiamine pyrophosphate, a dehydrogenase cofactor
- C)Tocopherol, a membrane antioxidant
- D)Calcitriol, a steroid hormone
- E)Retinal, a component of rhodopsinGABARITO
Explicação
Vitamin A deficiency causes night blindness and xerophthalmia with Bitot spots. Retinal, the aldehyde form of vitamin A, is a component of rhodopsin in rod cells and is essential for dim light vision. The ocular findings make this deficiency pattern straightfo... Ver explicação completa e trilha adaptativa →