vitamin a or retinol molecule. skeletal formula.

retinol vitamin molecule formula acid acne atomic atoms betacarotene broccoli c20h30o carotene carotenoid carrot chemical chemistry cod composition compound deficiency drawing drug eye flat hypervitaminosis icon isotretinoin line liver medical medicine molecular oil palmitate provitamin retina retinal retinoic retinoid retinyl science skeletal structure supplement supplementation vitamine