There are three essential requirements to developing strong healthy bones: adequate calcium, adequate vitamin D, and regular exercise. Failure to meet any of these requirements will compromise bone strength. Since it is estimated that 80-90% of our bone mineral density is deposited in the first 18 years of life, it is essential that all children and especially adolescents consistently meet these requirements.
Calcium: The recommended intake for children increases with age.
Ages 1-3 years 700mg/day
Ages 4-8 years 1000mg/day
Ages 9-18 years 1300mg/day
This calcium requirement can be met in many ways but the easiest way is through breat milk or formula in infancy and through milk products in childhood and adolescence. Dairy foods like milk, yogurt, and cheese are among the best natural sources of calcium. The percentage of fat in milk and other dairy foods does not affect the calcium content. However, if your chid can’t or won’t eat dairy, calcium can also be found in tofu; edamame (soybeans); leafy greens like kale, spinach, or chard; broccoli; certain beans and nuts; and calcium-fortified orange juice. Food companies even add it to cereals and breads.
Tums tablets provide anywhere from 200-1000mg of calcium per tablet and ideally should be taken after meals. Viactiv calcium chews provide 500mg per square.
Vitamin D: Infants require 400 IU of vitamin D per day from birth in order to adequately utilize the calcium in their die, and that requirement increases to 600 IU daily. Formula is supplemented with vitamin D but breastfed infants should receive a supplement from birth. If your baby is formula-fed and taking less than 32 ounces daily, you also should ask your health care provider about giving your baby a vitamin D supplement. Some individuals require even more vitamin D, e.g. premature and dark-complexioned infants.
We produce vitamin D from sun exposure but do not get adequate sun exposure in New England during the late fall, winter, and early spring months. To produce adequate Vitamin D from sun exposure, an infant wearing a diaper requires 30 minutes of exposure per week and an older child requires 2 hours per week with no hat. Since sunscreen, even with very low SPF, blocks nearly all vitamin production, and is recommended to protect skin from sun damage and prevent skin cancer, most vitamin D will be obtained through supplementation as above, or through foods that are rich in vitamin D, such as fatty fish, fish oils, or fortified foods such as dairy or cereal.
Exercise: The final essential requirement for building strong bones is regular exercise. All children should receive at least 1 hour of activity per day – and more is even better. Sports are great but so is brisk walking, running around playing or jumping rope. A variety of activities is also important to prevent overuse injuries.
As a corollary, screen time – meaning TV, videos, video games, and phone/tablets – should be limited to not more than 1 hour per day. (An exception to this limit is that time required for homework.)
By ensuring that our children receive the recommended amounts of calcium and Vitamin D and regular intense activity throughout their growing years, they will develop strong healthy bones with a reduced risk of fractures throughout their life.
Adapted from Pediatric Associates of Hampton & Portsmouth ‘Healthy Bones” handout, 2010
Additional resources: KidsHealth Parent Handout on Vitamin D and Calcium
