New research shows that taking high does of vitamins often provide no health benefit, and can even cause harm. "...We've looked for the active ingredient in these vitamins to find out what is working and have been unable to find anything," said Dr. David Katz, Good Morning America medical correspondent. Dr. Katz warned viewers of the potential dangers associated with megadoses of popular vitamins such as vitamin E (heart failure), vitamin A (hip fracture), and vitamin C, which can interfere with other medical treatments such as chemotherapy.

Patients appear to judge physicians based on bedside manner, rather than technical knowledge and skills, according to a new survey of 2 large U.S. medical centers. Patients agreed that the qualities that defined an "ideal" doctor were honesty, compassion, and respectfulness. Describing their worst experiences, patients cited providers' arrogance, dismissive attitude, and "callousness" in discussing their condition.

The use of attention deficit disorder medication rose nearly 19% among adults ages 20-to-44 in 2005, while falling 5% in children under the age of 10, according to a report reviewing U.S. drug safety from Medco Health Solutions. Some critics say ADHD drugs are over-prescribed, especially among children. The medications have faced growing scrutiny in recent months following a recommendation by an FDA advisory panel calling for a black box warning on ADHD drugs in February.

Numerous studies have shown that grapefruit juice interferes with the effectiveness of many widely used medicines. Now researchers at London Health Sciences Center in Ontario have discovered why: grapefruit juice blocks an enzyme in the intestines that metabolizes many drugs and toxins into substances that are less potent or more easily excreted or both. This increases the potency of the drug by letting more of it enter the bloodstream. Grapefruit interacts with this enzyme only in the intestines, not in the liver or other places where it is found; therefore the effect is seen only with medicines taken orally.