Vitamin A was first identified in 1913 because of its crucial role in vision. Subsequent discovery of its many other duties show that a deficiency will cause a broad range of health problems.
Vitamin A is not a single compound but actually comprises a fat-soluble family of molecules that includes retinol, retinal, retinoic acid, and retinyl ester. The term vitamin A also includes certain plant carotenoids called provitamin
OR
OR
