Every day is an omnivore’s dilemma as we’re forced to consult encyclopedias, ask doctors and experts and guess what will keep us healthy in the coming years. One thing is certain: supplements aren’t going to cut it. Registered dietitian Susan Levin, director of nutrition education for the Physicians Committee for Responsible Medicine, Washington D.C., says it’s always a good idea to speak to your doctor before you switch to a supplement, no matter how harmless it may seem.