Doctors say it's an open question, deserving of a closer look.
Zinc is a mineral crucial to good health. Too little of it can result in stunted growth, decreased immune functions, or even damage to the brain. Zinc is plentiful in meats, especially beef, but other foods such as cereals can offset the body's ability to absorb it. Severe zinc deficiency, common in some third world countries, is easy enough to spot. But the much more common moderate deficiency is harder to diagnose, though it can cause health problems.