Children's Bone Health and Calcium: Other FAQs

There are common questions that we can answer about all health topics, such as "What is it?" and "How many people are affected." Answers to these questions are found under Condition Information. Each health topic frequently has specific questions that pertain only to that topic. We have answered those in this section. 

• What is peak bone mass?
• What if kids do not like milk or are lactose intolerant?
• How is vitamin D related to healthy bones?
• What can I do to increase my child's calcium intake?

What is peak bone mass?

Peak bone mass is the amount of bone a person has in his or her late adolescence or early adult years. The body builds most bone by age 18 years in girls and by age 20 years in boys.¹ In other words, by their late teens or early 20s, most people's bones are as dense and strong as they will ever be. Maximizing peak bone mass as a teen reduces the risk for osteoporosis (thin, weak bones that break easily) later in life.

What if kids do not like milk or are lactose intolerant?

Milk and dairy products are good sources of calcium, which is critical to building bone mass to support physical activity and reduce the risk of fractures. But some people may have lactose intolerance. Lactose is the sugar found in milk and dairy foods. When lactose is not digested, it may cause an upset stomach, bloating, diarrhea, and gas.

Lactose intolerance is not common in young children. It is less of a problem if milk or dairy foods are taken with meals. Talk to your pediatrician if you think your child might have trouble digesting milk and dairy foods.

For additional information, check out the Lactose Intolerance topic or visit the What if Milk is a Problem for my Kids? section of the Milk Matters website.

How is vitamin D related to healthy bones?

Vitamin D is important for building strong bones because it helps the body absorb the calcium in milk and other foods. Children who do not get enough vitamin D can develop rickets, a condition in which the bones become soft, thin, and brittle.

In a large health survey, 9% of U.S. children, teens, and young adults ages 1 to 21 years had vitamin D levels low enough to put them at risk for rickets. Among teenagers, 61% were severely deficient in vitamin D. Children who did not drink milk frequently were at higher risk for vitamin D deficiency.¹

Sunlight stimulates the body to make vitamin D in the skin. However, when spending time outdoors, children should wear protective clothing and use sunscreen to prevent sunburn, which can lead to skin cancer later in life.² (For more information about sun safety, visit the American Academy of Pediatrics website.)

Few foods contain vitamin D naturally. Most of the vitamin D in our diets comes from foods that have been fortified with it, such as milk, orange juice, yogurt, and certain breakfast cereals.

The following chart lists selected food sources ranked by the approximate amount of vitamin D they contain in a standard portion:

Adapted from: Office of Dietary Supplements, National Institutes of Health. (2011). Dietary supplement fact sheet: Vitamin D. Retrieved April 21, 2012, from http://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/

As with calcium, children and teens need different amounts of vitamin D in their diets depending on their age:³

The American Academy of Pediatrics recommends that breastfed infants receive a vitamin D supplement of 400 IU per day beginning a few days after birth and continuing throughout childhood.⁴ This is because breast milk, while considered best for babies for many other reasons, is not a good source of vitamin D. Infants who are fully or partially fed formula but drink less than 32 ounces of vitamin D-fortified formula a day also need the daily 400 IU vitamin D supplement.⁵

What can I do to increase my child's calcium intake?

Put calcium on the table at every meal. Be a good example for your children, and drink milk in front of them. Include low-fat milk in every meal and include other calcium-rich and calcium-fortified choices over the course of the entire day. The Milk Matters website offers tools for parents to help increase their child's calcium intake. Resources include meal and snack ideas along with printable materials and:

• Information about bone health
• Tips and suggestions for calcium-rich foods
• Strategies for increasing calcium consumption

1. National Institutes of Health. (2010, February). Keeping bones strong and healthy: Let's talk about osteoporosis. NIH News in Health. Retrieved May 8, 2012, from http://newsinhealth.nih.gov/2010/February/feature1.htm [top]
2. Kumar, J., Muntner, P., Kaskel, F. J., Hailpern, S. M., & Melamed, M. L. (2009). Prevalence and associations of 25-hydroxyvitamin D deficiency in US children: NHANES 2001–2004. Pediatrics, 124(3), e362–370. [top]
3. Wagner, C. L., & Greer, F. R. (2008). Prevention of rickets and vitamin D deficiency in infants, children, and adolescents. Pediatrics, 122(5), 1142–1152. [top]
4. Institute of Medicine. (2010, November). Dietary reference intakes for calcium and vitamin D. Report brief. Retrieved April 21, 2012, from http://www.iom.edu/Reports/2010/Dietary-Reference-Intakes-for-Calcium-and-Vitamin-D.aspx [top]
5. Centers for Disease Control and Prevention. (2009). Breastfeeding: Vitamin D supplementation. Retrieved May 8, 2012, from http://www.cdc.gov/breastfeeding/recommendations/vitamin_D.htm [top]
6. American Academy of Pediatrics. (2012). Vitamin D and your baby. Retrieved May 22, 2012, from http://www.healthychildren.org/English/healthy-living/nutrition/Pages/Vitamin-D-And-Your-Baby.aspx?nfstatus=401 [top]