Children thrive on dozens of nutrients that work together to promote growth and development. While no single nutrient or group of nutrients is any more important to a child's well-being, these five get a lot of attention whenever kids' nutrition is discussed.
Calcium: A Must-Have Nutrient for Bone Health
Calcium, the most abundant mineral in the body, maximizes bone growth and shores up the skeleton during childhood and beyond. A small but significant amount of calcium in the bloodstream is needed for a normal heartbeat, blood clotting, and muscle function. The body withdraws the calcium it needs from bones to maintain blood levels, which is partly why children need adequate calcium every day. Many kids don't get enough for their nutritional needs.
Keith-Thomas Ayoob, RD, associate professor in the department of pediatrics at Albert Einstein College of Medicine in New York, says, "American kids are suffering from a calcium crisis, and it does not bode well for their bone health -- now or in the future."
Teenage girls in particular are among those with the lowest calcium intake relative to their needs. Calcium deficiency is especially dicey during adolescence when the body forms about half the bone mass it will ever have. Consistently coming up short on calcium during these years is one of the risk factors for developing osteoporosis decades later. It's even worse for females because of their greater risk for the condition.
How much calcium is enough? According the Institute of Medicine, kids' daily calcium needs depend on age:
- Kids 1- to 3 years old need 500 milligrams.
- 4- to 8-year-olds need 800 milligrams.
- Kids 9 to 18 years old need 1,300 milligrams.
Ayoob says part of the solution to low calcium intake is offering young children and teens calcium-rich beverages and snacks rather than soft drinks, snack chips, and candy. Eight ounces of white or flavored milk, 8 ounces of yogurt, and 1.5 ounces of hard cheese each contain about 300 milligrams of calcium.
While dairy foods are excellent sources of calcium, calcium is also plentiful in plant products such as fortified orange juice and soy beverages, tofu processed with calcium sulfate, and certain breakfast cereals (check the label to be sure).
The benefits of making high-calcium foods, particularly dairy, part of your child's daily diet may extend beyond building strong bones. Sheah Rarback, RD, director of nutrition and associate professor at the Mailman Center for Child Development at the University of Miami, says, "Emerging research suggests that calcium in dairy foods as part of a balanced diet helps adults achieve and maintain a healthy weight. And the same may be true for children."
Preliminary evidence shows dairy does work for kids. One study linked higher calcium intake to lower body fat levels in children aged 2 to 8. Milk and dairy foods were the main sources of calcium in the children's diets in the study.
Vitamin D is important for the absorption of calcium to help form and maintain strong bones. Since breast milk does not contain significant amounts of vitamin D, the American Academy of Pediatrics (AAP) recommends all breastfed and partially breastfed infants receive 400 IU of vitamin D from liquid supplements each day.
Milk fortified with vitamin D is one of the few dietary sources of Vitamin D. So children over 1 should drink 32 ounces of fortified milk each day or get other sources of vitamin D. For these children, the AAP recommends 400 IU/day of vitamin D.
Protein: Essential to Growth
"Protein is part of every single body tissue," Rarback says. "That gives you an idea of how important it is to children who are, by their very nature, growing all the time."
Protein provides calories, but its amino acids are what the body really needs. Amino acids are the raw materials for building new cells and tissues and the compounds that direct bodily processes, including those involving enzymes and hormones.
Protein is found in animal and plant foods. But there is a difference. Animal foods, particularly eggs, supply the essential amino acids (EAA) that your child's body cannot make. No plant food supplies all of the amino acids, so vegans (those who eat no animal food products) must eat an array of protein-packed plant foods to get the EAA they need. Vegetarians who include dairy foods and eggs typically satisfy EAA needs as long as they eat enough.
Protein needs are highest on a pound-per-pound basis during infancy. They increase again just before adolescence as the body readies for another growth spurt. Here is a list of kids' daily protein needs based on age:
- Kids 1 to 3 years old need about 13 grams.
- 4- to 8-year-olds need 19 grams.
- 9- to 13-year-olds need 34 grams.
- The need for 14- to 18-year-olds depends on gender -- 46 grams for females and 52 grams for males.
Ayoob says, "Protein is not a problem for most kids, even those who don't eat meat or don't eat it consistently." For example, just 16 ounces of milk or yogurt or 2 ounces of meat, chicken, or seafood and an egg satisfy a 3-year-old's daily protein needs.
Fiber: Complex Yet Simple
Kids need fiber for good nutrition and healthy growth. But fiber is an oddity among carbohydrates. It's a complex carbohydrate minus the calories. Your child can't digest dietary fiber to get at the energy it provides. So what makes it so good?
"Kids need fiber for the same reasons adults do," Rarback says. "And like their elders, children get way less fiber than they need."
Rarback says studies show fiber wards off type 2 diabetes and elevated blood cholesterol levels in adults and, possibly, children. Fiber's confirmed benefits for kids include fending off constipation and promoting fullness. High-fiber foods, including whole grains, legumes, fruits, and vegetables, keep kids fuller longer, a boon in the battle of the bulge. And fiber-filled foods are rich in vitamins and minerals.
To figure fiber for kids, Rarback uses the method endorsed by the American Academy of Pediatrics, and you can too. Simply add five to your child's age to determine daily fiber needs in grams. So a 13-year-old needs about 18 grams a day.
Having a number in mind helps when you read food labels, but it's not necessary to track every gram of fiber your child eats. "Instead," Rarback says, "make whole grains, fruits, and vegetables available to your child every day. And consider adding legumes to your family's meals to get the fiber your child needs." A simple way to get a start on the daily fiber needs is to offer your child a fiber-rich breakfast such as bran cereal or shredded wheat.
Antioxidants Battle Disease
Antioxidant nutrients, including vitamins C and E, beta-carotene, and the mineral selenium, receive a lot of attention for their potential to head off chronic conditions in adults, including cancer and heart disease. While their effects are still under study, experts regard antioxidants as the "superheroes" of nutrients.
Antioxidants battle the effects of free radicals. Free radicals are by-products of normal metabolism that also form when you're exposed to air pollution, cigarette smoke, and strong sunlight. As free radicals accumulate, they can damage DNA, the genetic blueprint for cell reproduction, as well as other cell parts.
While there's little research to back up the effects of antioxidants on a child's well-being, Ayoob and Rarback agree that you can't go wrong by offering children antioxidant-rich foods, such as whole grains and produce.
Brightly colored fruits and vegetables, including blueberries and other berries, broccoli, spinach, tomatoes, sweet potatoes, cantaloupe, cherries, and carrots are among the produce offering the most antioxidants.
Iron Is a Crucial Nutrient
Your child depends on iron to grow. Red blood cells need iron to ferry oxygen to every cell in the body. Iron also plays a role in brain development and function.
"Iron is so critical to brain development that the negative effects of a daily iron deficiency on cognition may be irreversible, even when the shortfall is small," Rarback says.
According to the American Academy of Pediatrics, iron deficiency is the most common nutritional deficiency in America, affecting mostly older infants, young children, and women in their childbearing years. Small children are at risk because they grow so fast. Teenage girls and women must make up for monthly blood losses with iron-rich foods or dietary supplements. An iron deficiency can lead to anemia.
Both animal and plant foods provide iron. Animal products, such as meat, dark meat poultry, and seafood, supply heme iron, the form of iron the body absorbs the best. Plant foods, including spinach and legumes, supply nonheme iron. Nonheme iron is also the type of iron added to breads, cereals, pasta, rice, and fortified grains.
A steady supply of fortified grains can provide enough iron, even for those who don't eat meat and who should take a daily multivitamin with iron for safety's sake.
Also, "you can boost nonheme iron absorption by adding a source of vitamin C," Ayoob says. "Offer kids foods such as oranges, orange juice, tomatoes, kiwi, strawberries, or red bell pepper with each meal to make the most of nonheme iron."