By Michael Ormsbee, PhD, Florida State University
Edited by Kate Findley and proofread by Angela Shoemaker, Wondrium Daily
Although the nutritional needs for children are similar to adults in most ways, you should be aware of some areas where extra attention is required. Professor Ormsbee discusses nutrients and elements of particular importance for children: calcium, iron, and water intake.
Nutrient Needs for Children: Calcium
The first nutrient you should focus on when it comes to raising healthy children is calcium. Calcium is required for proper bone growth and strength. The total intake along with vitamin D and exercise lay the foundation for bone strength into adulthood.
In fact, some geriatric conditions are caused by lack of physical activity, lack of calcium, and lack of vitamin D as a child and as a young adult. These conditions include osteopenia, which is low bone mineral density, and osteoporosis, which is very low bone density or highly porous and brittle bones.
Both osteopenia and osteoporosis are often considered pediatric diseases with geriatric consequences. This means that how you treat your bones as a child will have an impact on your health when you become older.
Check out the current Dietary Reference Intakes (DRIs) for specific recommendations. Dairy foods provide about 75% of the calcium in North America, but foods like fortified orange juice and cereals as well as spinach contain calcium, too. Supplements can be used if calcium-containing foods can’t be added to the diet.
Importance of Iron
The other major micronutrient to consider for children is iron. Iron is actually one of the most common nutrient deficiencies worldwide.
Iron helps transport both oxygen and carbon dioxide throughout the body. When children and adolescents do not get enough iron in their diets, iron-deficiency is likely.
Iron-deficiency anemia might occur if you have a low level of red blood cell production. Low levels of iron, in general, can lead to fatigue, brittle hair and nails, pale skin, and poor growth.
An early study from the Department of Pediatrics at Baystate Medical Center found that about 45% of female teenage endurance athletes and about 15% of male teenage endurance athletes were iron deficient following an 11-week competitive season. For active people, the lack of ability to transport oxygen in the blood is not healthy and will reduce performance. These findings are specific to this study, but other studies support the overall conclusions.
During the teenage years, girls need 15 to 18 milligrams (mg) of iron per day, and boys need 11 mg. Teen girls need more because of the loss of iron that occurs with menses.
Spinach, most beans, steak, and fortified cereals can all easily provide enough iron. One caveat is that iron toxicity can occur anywhere around 20 mg per kilograms (kg) of body weight and beyond.
While toxicity isn’t likely to occur from eating whole foods, it could happen if a child swallowed around 15-20 iron tablets in supplement form. This may sound odd, but for some children, iron supplements or multivitamins might look like candy. Thus, always be cautious with what is available to your children.
Hydration for Active Children
Outside of these nutrient issues for children, their hydration needs must also be considered—particularly if your child is very active. Young children end up with a higher core temperature and they sweat less than adolescents do, despite having more sweat glands per unit of skin area than either adolescents or adults.
Both a disadvantage and advantage for children is their large surface area per unit of body mass compared to adults. This body surface to mass ratio causes them to heat up more quickly from the environment. However, because of their high body surface to mass ratio, children also cool at a faster rate than adults.
The research is actually mixed as to whether or not children are at a disadvantage in terms of regulating their body temperature—a process called thermoregulation. One landmark study had five prepubertal girls and five college-aged women exercise at a slow pace on a treadmill for 50 minutes in three different environmental temperatures. As the temperature increased for each trial, the young girls could not tolerate exercise for quite as long as the college-aged women.
In fact, at all environmental temperatures, the girls had higher heart rates and higher temperatures than the women. This likely had to do again with the body surface area to weight ratio. Drinking water or even diluted sports drinks can help compensate for this effect—especially during vigorous exercise and spending time outside in warm weather.
Tomorrow’s article will examine the other end of the spectrum: nutrition and exercise changes that occur as we age.
Michael Ormsbee is an Associate Professor in the Department of Nutrition, Food, and Exercise Sciences and Interim Director of the Institute of Sports Sciences and Medicine in the College of Human Sciences at Florida State University. He received his MS in Exercise Physiology from South Dakota State University and his PhD in Bioenergetics from East Carolina University.
