Zinc in Toddlers
The 22 essential minerals can be broadly categorized into two types: major minerals and trace minerals. Relatively large quantities of potassium, calcium, magnesium and other major minerals are required for good health, whereas the body only needs small amounts of iron, copper, zinc and other trace minerals to stay healthy. Despite its low intake requirement, zinc is involved with the function of all bodily cells. Its key role in growth and development makes the nutrient especially important for children.
Nearly all physiological processes, from breathing to digesting food and producing energy, are catalyzed by enzymes. Zinc is required by the enzymes involved in more than 100 of these vital chemical reactions, including immune system function, wound repair and the cell division that fuels growth and development. Zinc gives structure to cell membranes and bodily proteins, and is necessary for proper sexual maturation. It’s also integral to a fully developed sense of taste and smell, contributes to low-light visual acuity and helps regulate appetite.
Only zinc and five other essential trace minerals have established recommended dietary allowances. Because the body doesn’t have a specified mechanism for storing zinc, it’s necessary to maintain a consistent intake to prevent deficiency. For toddlers from the ages of 1 to 3, the recommended dietary allowance for zinc is 3 milligrams per day.
Zinc is available in a wide range of foods, both of animal and plant origin. Oysters are especially high in zinc, but beef and other red meats are also rich sources. A 1.5-ounce serving of cooked beef provides about 3 milligrams of zinc. Turkey and chicken, which are easier to chew and more palatable to most toddlers than oysters or beef, are also high in zinc. Per 1.5-ounce serving, dark-meat turkey and chicken provide nearly 2 milligrams and 1 milligram, respectively. Dairy products are another good source. Yogurt and milk supply almost 2 milligrams of zinc each per 1-cup serving. Nuts, whole grains, fortified ready-to-eat cereals, lentils and dried beans and peas supply significant amounts of zinc, as well.
Zinc is generally more readily absorbed from foods of animal origin. Meat, poultry, fish and dairy products contain significant levels of cysteine and methionine, two amino acids that enhance the body’s ability to absorb zinc. Nuts, legumes and whole grains, however, are high in phytic acid, a compound that binds to zinc and reduces its rate of absorption. While these plant-based foods are still good sources of the mineral, a diet high in such foods can result in mild zinc deficiency. For this reason, vegetarian and vegan toddlers are at a higher risk of zinc deficiency than those that consume meat and dairy products. In children of any age, mild zinc deficiency can negatively affect growth, appetite, cognitive development and immune function.
Like all minerals, too much zinc can be toxic. For this reason, the body efficiently regulates its zinc levels by absorbing only what it needs from the diet. Supplements are more likely to cause toxicity, whether acute or chronic, than a zinc-rich diet. Zinc supplements are sometimes used on a short-term basis to treat children with persistent diarrhea. These supplements typically provide 20 milligrams of zinc per day, according to the National Institutes of Health. For healthy toddlers, however, the tolerable upper intake level for zinc is just 7 milligrams a day.
- Office of Dietary Supplements: Zinc
- Linus Pauling Institute at Oregon State University: Zinc
- Better Foods For Kids, 2nd Edition; Joanne Saab, R.D., et al.
- American Dietetic Association Complete Food and Nutrition Guide; Roberta Larson Duyff, M.S., R.D.
- Wellness Foods A to Z; Sheldon Margen, M.D., et al.