Best Sources of Zinc

zinc

What can high-zinc foods do for you?

Help balance blood sugar Stabilize your metabolic rate Prevent a weakened immune system Support an optimal sense of smell and taste What events can indicate a need for more high-zinc foods?

Impaired sense of taste or smell Lack of appetite Depression Growth failure in children Frequent colds and infections

Calf's liver is an excellent source of zinc while very good sources of zinc include crimini mushrooms, shiitake mushrooms, venison, and spinach. World's Healthiest Foods rich in
zinc

For serving size for specific foods, see Nutrient Rating Chart below at the bottom of this page. Description

What is zinc?

Zinc is a micromineral needed in the diet on a daily basis, but only in very small amounts (50 milligrams or less). The other microminerals that all humans must get from food are arsenic, boron, cobalt, copper, chromium, fluorine, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc.

The first research studies to demonstrate the zinc's important in the diet focused on the issue of growth. When foods did not supply sufficient amounts of zinc, young men in Iran and Egypt were found to have impaired overall growth as well as impaired sexual maturation. These initial studies on zinc reflected some of the key functions served by this mineral, including regulation of genetic activity and balance of carbohydrate metabolism and blood sugar. How it Functions

What is the function of zinc?

Regulating genetic activities

Zinc is an important regulator of many genetic activities. The cells of our body each have a special compartment called the nucleus, and inside the nucleus are approximately 100,000 genes. These genes provide instructions for the cell, and the cell has to decide which instructions to read. Zinc is essential for reading genetic instructions, and when diets do not contain foods rich in zinc, instructions get misread, or not read at all. (In biochemistry terms, the gene-reading process that requires zinc is called gene transcription.) Supporting blood sugar balance and metabolic rate

Insulin, a hormone made by the pancreas, is often required to move sugar from our bloodstream into our cells. The response of our cells to insulin is called insulin response. When the foods in our diet do not provide us with enough zinc, insulin response decreases, and our blood sugar becomes more difficult to stabilize. Metabolic rate - the rate at which we create and use up energy - also depends on zinc for its regulation. When zinc is deficient in the diet, metabolic rate drops (along with hormonal output by our thyroid gland). Supporting smell and taste sensitivity

Gustin is a small protein that is directly involved in our sense of taste. Zinc mus be linked to gustin in order for our sense of taste to function properly. Because of this relationship between zinc and taste, and because taste and smell are so closely linked in human physiology, impaired sense of taste and smell are common symptoms of zinc deficiency. Supporting immune function

Many types of immune cells appear to depend upon zinc for optimal function. Particularly in children, researchers have studied the effects of zinc deficiency (and zinc supplementation) on immune response and number of white blood cells, including specific studies on T lymphocytes, macrophages, and B cells (all types of white blood cells). In these studies, zinc deficiency has been shown to compromise white blood cells numbers and immune response, while zinc supplementation has been shown to restore conditions to normal. Deficiency Symptoms

What are deficiency symptoms for zinc?

Because of the link between zinc and the taste-related protein called gustin, impaired sense of taste and/or smell are common symptoms of zinc deficiency. Depression, lack of appetite, growth failure in children, and frequent colds and infections can also be symptomatic of insufficient dietary zinc. Toxicity Symptoms

What are toxicity symptoms for zinc?

Zinc toxicity has been reported in the research literature, and in 2000 the National Academy of Sciences set a tolerable upper limit (UI) of 40 milligrams for daily intake of zinc. (This limit applies to all individuals age 19 and over.) A metallic, bitter taste in the mouth can be indicative of zinc toxicity, as can stomach pain, nausea, vomiting, cramps, and diarrhea mixed with blood. Impact of Cooking, Storage and Processing

How do cooking, storage, or processing affect zinc?

Like most minerals, zinc is present in many different forms in food, and can vary greatly in its response to cooking and processing. In some foods, where a greater percent of zinc is found in water-soluble form and contact with water is great, high losses of zinc can occur.

For example, when navy beans are cooked, 50% of the original zinc is lost. The processing of wheat is another example of the susceptibility of zinc to substantial loss. In 60% extraction wheat flour - the kind that is used to make over 90% of all breads, baked goods, and pastas sold in the U.S., almost 75% of the original zinc is lost. Factors that Affect Function

What factors might contribute to a deficiency of zinc?

In addition to dietary deficiency, problems in the digestive tract can contribute to zinc deficiency. These problems include irritable and inflammatory bowel disorders, as well as insufficient output by the pancreas that prevents proper digestion of food.

Protein deficiency, and deficiency of one particular part of protein - the amino acid cysteine - can also contribute to zinc deficiency by preventing synthesis of transport and storage molecules that are used to shuttle and store zinc in the body.

Loss of zinc through chronic diarrhea or profuse sweating (as might occur with heavy physical labor or athletic training) can also contribute to deficiency of this mineral. Nutrient Interactions

How do other nutrients interact with zinc?

A Tolerable Upper Limit (UL) for zinc of 40 milligrams per day was set by the National Academy of Sciences in 2000 for all adults 19 years and older. The establishment of this limit was largely related to the ability of zinc - particularly supplemental zinc - to impair the status of other nutrients.

The most important of these nutrients are copper and calcium. Even at moderate doses of 18-20 milligrams that can easily be obtained from food, zinc can compromise the body's supply of copper unless foods rich in copper are also included in the diet. When few foods high in calcium are included in the diet, high levels of zinc intake (usually obtained from supplements) can also decrease absorption of calcium from the intestine into the body.

Although zinc is associated with these potential detrimental effects on copper and calcium, it is also supportive of other nutrients. The best studied of these nutrients in vitamin A. Without zinc, vitamin A cannot be effectively transported around the body, and cannot efficiently be mobilized when it is needed. Health Conditions

What health conditions require special emphasis on zinc?

Zinc may play a role in the prevention and/or treatment of the following health conditions:

Acne Alcoholism Alopecia Alzheimer's disease Anorexia nervosa Atopic dermatitis Benign prostatic hypertrophy Cervical dysplasia Common cold Crohn's disease Diabetes Epilepsy Graves' disease Herpes simplex HIV/AIDS Infertility (male) Inflammatory bowel diseases Influenza Macular degeneration Osteoarthritis PMS Psoriasis Rheumatoid arthritis Seborrheic dermatitis Senile cataracts Food Sources

What foods provide zinc?

Calf's liver is an excellent source of zinc. Crimini mushrooms, shiitake mushrooms, spinach, and venison are very good sources of zinc.

Good sources include asparagus, chard, scallops, lamb, beef, maple syrup, shrimp, green peas, yogurt, oats, pumpkin seeds, sesame seeds, turkey, miso, and spelt.

In order to better help you identify foods that feature a high concentration of nutrients for the calories they contain, we created a Food Rating System. This system allows us to highlight the foods that are especially rich in particular nutrients. The following chart shows the World's Healthiest Foods that are either an excellent, very good, or good source of zinc. Next to each food name, you'll find the serving size we used to calculate the food's nutrient composition, the calories contained in the serving, the amount of zinc contained in one serving size of the food, the percent Daily Value (DV%) that this amount represents, the nutrient density that we calculated for this food and nutrient, and the rating we established in our rating system. For most of our nutrient ratings, we adopted the government standards for food labeling that are found in the U.S. Food and Drug Administration's "Reference Values for Nutrition Labeling." Read more background information and details of our rating system. World's Healthiest Foods ranked as quality sources of
zincFoodServing
SizeCalsAmount
(mg)DV
(%)Nutrient
DensityWorld's
Healthiest
Foods RatingWorld's Healthiest
Foods RatingRuleDV>=75% OR
Density>=7.6 AND DV>=10%DV>=50% OR
Density>=3.4 AND DV>=5%DV>=25% OR
Density>=1.5 AND DV>=2.5%Public Health Recommendations

What are current public health recommendations for zinc?

The Recommended Dietary Allowances for zinc, set in 1999 by the Institute of Medicine at the National Academy of Sciences, are as follows: Males and females, 0-6 months: 2 milligrams Males and females, 6-12 months: 3 milligrams Males and females, 1-3 years: 3 milligrams Males and females, 4-8 years: 5 milligrams Males and females, 9-13 years: 8 milligrams Males 14 years and older: 11 milligrams Females 14-18 years: 9 milligrams Females 19 years and older: 8 milligrams Pregnant females 18 years or younger: 12 milligrams Pregnant females 19 years and older: 11 milligrams Lactating females 18 years or younger: 13 milligrams Lactating females 19 years and older: 12 milligrams

The National Academy of Sciences set a tolerable upper limit (UI) of 40 milligrams for daily intake of zinc. (This limit applies to all individuals age 19 and over.) For more details on this, see the Toxicity Symptoms section above.

References

Cerhan JR, Saag KG, Merlino LA et al. Antioxidant micronutrients and risk of rheumatoid arthritis in a cohort of older women. Am J Epidemiol. 2003 Feb 15; 157(4):345-54 2003. Chandra RK. Micronutrients and immune functions. Ann NY Acad Sci 1990;587:9-16 1990. Dunn MA, Blalock TL, Cousins RJ. Metallothionein. Proc Soc Exp Biol Med 1987;187:107-119 1987. Festa MD, Anderson HL, Dowdy RP, et al. Effect of zinc intake on copper excretion and retention in men. Am J Clin Nutr 1985;41:285-292 1985. Forbes RM, Erdman JW Jr. Bioavailability of trace mineral elements. Ann Rev Nutr 1983;2:213-231 1983. Groff JL, Gropper SS, Hunt SM. Advanced Nutrition and Human Metabolism. West Publishing Company, New York, 1995 1995. Hambridge KM, Casey CE, Krebs NF. Zinc. In: Mertz W. (Ed), Trace elements in human and animal nutrition. 5th Edition, Volume 2. Academic Press, Orlando, Florida, 1986 1986. Meiners CR, Derise NL, Lau HC, et al. (1976). The content of nine mineral elements in raw and cooked mature dry legumes. J Arg Food Chem 1976;24:1126-1130 1976. National Research Council. Recommended Dietary Allowances, 10th ed. Washington, DC: National Academy Press; 1989. 1989. Pedersen B, Eggum BO. The influence of milling on the nutritive value of flour from cereal grains. Part 2. Wheat. Qual Plant Plant Fds Hum Nutr 1983;33:51-61 1983. Prasad AS, Cavdar AO, Brewer GJ, et al. Zinc deficiency in human subjects. Alan R Liss, Inc, New York, 1983 1983. Smith JC Jr, McDaniel EG, Fan FF, et al. Zinc: a trace element in vitamin A metabolism. Science 1973;181:954 1973. Solomons NW, Cousins RJ. Zinc. In: Solomons NW and Rosenberg IH. (Eds). Absorption and malabsorption of mineral nutrients. Alan R Liss, New York, 1984 1984. Spencer H. Minerals and mineral interactions in human beings. J Am Diet Assoc 1986;86:864-867 1986. Wada L, King JC. Effect of low zinc intakes on basal metabolic rate, thyroid hormones and protein utilization in adult men. J Nutr 1986;116:1045-1053 1986. Wu FY-H, Wu C-W. Zinc in DNA replication and transcription. Ann Rev Nutr 1987;7:251-272 1987.

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