单选题 .  According to one definition, the word "supplement" means "something added to complete a thing, to extend or strengthen the whole."
    Supplements can be very beneficial but you must be careful because, like any drug, all supplements pose potential risks. Before you start taking any, check with your doctor first.
    A supplement may be natural but that doesn't mean taking it is completely without risk. Many, if not all, supplements have the potential to interact with prescription or over-the-counter drugs, cause harmful side effects if taken inappropriately, or even make existing medical conditions worse. That's why it's critical that you tell your health care providers about any supplements you take. In a University of Michigan study one-third of the patients taking supplements were using ones that could interact with their heart medications. Be especially cautious if you're taking blood-thinning medication like aspirin, Coumadin (warfarin), or Plavix (clopidogrel); many supplements, such as ginkgo biloba (银杏), ginseng (人参), garlic, vitamine, fish oil, and coenzyme (辅酶) Q10, also have blood-thinning properties, and the combined effect could lead to dangerous bleeding.
    Also, the label may say "natural" but that doesn't mean the supplements are any safer than medicinal drugs. They still include chemicals that have an effect on your body; that's why they work. So don't exceed the recommended dose, and don't take any supplement longer than advised. If you are pregnant or nursing, be doubly sure to check with your doctor before taking any supplements.
    In the next few years you're bound to hear more and more about natural alternatives for lowering cholesterol and protecting the heart. But before you jump on any bandwagons (花车), take heed: No supplement is a substitute for the lifestyle changes, particularly good eating habits. The fact is that scientists will probably never be able to duplicate (复制) the complex effects and myriad health benefits of foods like fruits, vegetables, and whole grains with a pill. And of course, lowering your cholesterol with supplements while eating steak and ice cream with abandon, or taking hawthorn (山楂) or CoQ10 to lower your blood pressure while doing nothing to relieve the stress caused by your nerve-racking job, won't do your heart or your arteries (动脉) much good in the end.1.  According to the passage, which one belongs to supplements? ______