<prompt> Which of the following combinations of biologically active molecules does vitamin A consist of?Retinol, retinal and retinoic acidRetinol, retinal and tetrahydrofolateRetinol, Iconjugase and retinoic acidPABA, retinal and retinaldehyde  <response>: The term retinoids is often used to include the natural and synthetic forms of vitamin A Retinol, retinal and retinoic acid are regarded as vitamers of vitamin A. beta-Carotene provitamin A: This is found in plant foods ref Satyanarayana 4th ed page 119 