system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
The oxidation of retinol produces:-
assistant
The correct answer is  Retinal (vitamin A aldehyde): 
This is an aldehyde form obtained by the oxidation of retinol. 
Retinal and retinol are interconvertible.
Key Concept:
Oxidation of retinol produces retinal
Oxidation of retinal produces retinoic acid.
Ref : Textbook of Biochemistry, Satyanarayana