The University of Maryland Medical Center advises 8 to 11 mg of zinc as the recommended daily allowance for adults. The U.S. National Library of Medicine explains zinc is necessary for the body's immune system, cell division and growth, sense of smell and taste, wound healing and carbohydrate breakdown. While serious deficiencies are rare, low levels can be found in alcoholics, people with anorexia or malabsorption syndromes, and people on restricted diets. Deficiency is more common over the age of 75. Deficiency symptoms include weight loss, hair loss, night blindness, depression and skin problems.
Fish and Shellfish
The University of Maryland Medical Center says one of the richest sources of zinc is oysters. A 100 g serving of oysters--a little over 3.5 oz.--contains 16.62 mg of zinc. Lobster contains 5.67 mg, while crab contains 3.54 to 4.27, depending on the kind of crab. Shrimp, clams, scallops, catfish and squid also contain zinc, but not in the quantity found in oysters.
Meat and Cheese
High-protein foods contain the highest amounts of zinc, so animal sources contain more than plant sources. According to the U.S. National Library of Medicine, beef, pork, lamb, poultry and cheese are good sources of zinc. With the exception of oysters, meat and many cheeses contain more zinc than fish and shellfish. Some cuts of meat contain more zinc than others. For example, the dark meat of chicken contains more zinc than the light.
Plant Sources
According to the U.S. National Library of Medicine, vegetables and fruit have lower levels of zinc than meat, fish and cheese. Also, zinc from plant sources is not as easily absorbed as zinc from animal sources. As a result, people who follow vegetarian or vegan diets may have deficient zinc levels.
The University of Maryland lists plant sources of zinc as legumes, such as lima beans, black-eyed peas, soybeans, pinto beans and peanuts; whole grains; miso; tofu; tahini; cooked greens; green beans; brewer's yeast; mushrooms; and pumpkin and sunflower seeds. Because zinc from plant sources is not as plentiful or easily absorbed, vegetarians may need to consume more to meet daily requirements. Supplements are also an option; most multivitamins contain zinc.
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