Dr. Al Sears wrote in a newsletter that “Synthetic, lab-created, vitamin A can build up to toxic levels and damage your liver. They’re sold as retinyl palmitate and they’re made by combining an ester of retinol with synthesized palmitic acid.” Is he correct that retinyl palmitate-containing supplements should be avoided?

This is not a highly toxic material but will be less useful in the body, as is true of all synthetic or semi-synthetic substances intended to be a replacement for some nutritional substance in actual foodstuffs. There are people with liver problems for whom too high an intake of this form of vitamin A would, in fact, be problematical. So it is safer to obtain vitamin A from actual food, especially meat, hens eggs, and so on.