The hazard of megadoses

Several common nutrients may be toxic when you scarf them down in megadose servings (amounts several times larger than the RDAs). Not only are large doses of vitamin A linked to birth defects, but they may also cause symptoms similar to a brain tumor. Niacin megadoses may cause liver damage. Megadoses of vitamin B6 may cause (temporary) damage to nerves in arms, legs, fingers, and toes. All these effects are more likely to occur with supplements. Pills slip down easily, but regardless of how hungry you are, you probably won’t eat enough food to reach toxic levels of nutrients. The best statement about the role of supplements in good nutrition may be a paraphrase of Abraham Lincoln’s famous remark about politicians and voters:
“You may fool all the people some of the time; you can even fool some of the people all the time; but you can’t fool all of the people all the time.” If Honest Abe were with us now and were a sensible nutritionist rather than President, he might amend his words: “Supplements are valuable for all people some of the time and for some people all the time, but they’re probably not necessary for all people all the time.”