Vitamins and supplements can be an important part of your overall plan for a healthy life. But they can be dangerous in certain situations. Before we had pharmaceuticals as we know them a variety of natural substances were used to treat illnesses. Then people knew about dosages, interactions and which ones to use for what conditions. Today we can walk into any number of stores and purchase these substances, none of which are regulated by the FDA. If you are on medication for any condition, you should consult your physician before adding supplements. If you take supplements and you schedule a doctor's visit or are having surgery these should be listed as medicines that you take. There can be serious reactions between your supplements and your prescribed medications. Supplements are wonderful things when used properly, so consult your doctor and be safe.