I am apprehensive about the conclusions reached by Meyers, Maloley, and Weeks1 in their article on the safety of antioxidant vitamins, particularly with respect to vitamin A, which they state is safe in dosages of up to 100 000 IU/d. They begin their argument with the estimation that 40% of the US population is consuming supplements and toxic reactions are rare. However, consuming supplements is not the same as taking megadoses of vitamins, which is what they ultimately condone. Prudence still dictates that if one is going to use supplements at all (the efficacy of which remains to be demonstrated), products providing nutrients in the range of the recommended dietary allowances2 remain the wisest choice. The generous, if not exorbitant, levels suggested to be safe by these authors cannot be supported.
The authors provide a very thorough description of acute and chronic toxic reactions to vitamin A. In
Schulz LO. Comments on the Safety of Antioxidant Vitamin Supplementation. Arch Intern Med. 1997;157(15):1776-1777. doi:10.1001/archinte.1997.00440360222037