Q. I take 50 milligrams of elemental zinc daily, but it looks like you should take only 40 milligrams per day?
A. Junaidah B. Barnett, PhD, a scientist in Tufts’ HNRCA Nutritional Immunology Laboratory who has studied zinc, replies: “The Upper Limit (UL) of the essential mineral zinc intake for adults is 40 milligrams per day. This includes intake from dietary, fortified and supplementary sources. We should get most of our nutrients from food. Good food sources of zinc include seafoods (such as oysters and crabs), beef and poultry. Good plant sources of zinc such as whole grains, beans, nuts and seeds add valuable fiber, protective antioxidants and phytonutrients, among many other benefits, to the diet. Those plant foods, however, contain phytate, which binds minerals such as zinc to form complexes that are not completely broken down during digestion, decreasing their bioavailability. “It is important to note that phytate compounds found in rich plant sources of zinc have been shown to have antioxidant properties that offer protection against cancer, cardiovascular disease and diabetes. Limitin