I recently read that the National Academy of Sciences has warned that taking large doses of vitamins C and E or other antioxidant supplements like selenium or beta-carotene may do more harm than good. What do you think? M. K.

Dear M.K.: While I do not claim prophetic insight I wrote the following over ten years ago: “Studies to date have focused on supplementation of single nutrients, primarily beta-carotene, vitamin E and vitamin C. While some benefits have been seen, it is entirely predictable that adverse effects will be also be encountered . . . The body’s antioxidant defense system is designed to work in concert. Supplementing only one component of the system will risk exhausting the resources in other parts of the system causing a breakdown.” This is precisely what those studies are demonstrating. Unless and until studies are undertaken looking at the effect of supplementing optimum levels of all vitamins and minerals simultaneously we will not see consistently positive results. By the way, if someone is thinking of stopping supplementation based on these headlines, the optimum levels I recommend are only half the “tolerable upper intake level” mentioned in the original Institute of Medicine report. –Dr. Peterson