As people age, their bones may become very weak and fragile — a condition called osteoporosis. It often develops unnoticed over many years, with no symptoms or discomfort until a bone breaks.
Fortunately, there are many things that people at all stages of life can do to build strong, healthy bones. Childhood and adolescence are especially important times for building bones and developing habits that support good bone health for life.
Bones grow in size during childhood, gaining mass and strength. The amount of bone mass you obtain while you are young determines your skeletal health for the rest of your life. The more bone mass you have after adolescence, the more protection you have against losing bone mass later.
Calcium and Nutrition
Good nutrition is vital for normal growth. Like all tissues, bone needs a balanced diet, enough calories, and appropriate nutrients, such as calcium. But not everyone follows a diet that is best for bone health. For example, the Institute of Medicine recommends a calcium intake for children ages 9 to 18 years of 1,300 mg/day (1,000 mg/day for children ages 4 to 8 years). Many children, however, have diets that do not meet this recommendation.
Calcium is the most important nutrient for reaching peak bone mass. It prevents and treats osteoporosis. Calcium is not made in the body — it must be absorbed from the foods we eat. To effectively absorb calcium from food, our bodies need Vitamin D.
Vitamin D can come from diet or exposure to sunlight. Before the development of fortified milk, lack of dietary Vitamin D caused rickets—a softening of the bones. Although rare in Western societies today, some children still develop rickets.
Most infants and young children in the United States get enough Vitamin D from fortified milk, but adolescents typically do not consume as many dairy products, and few foods contain substantial levels of the vitamin. Although exposure to sunlight can help our bodies make Vitamin D, it is not a practical or safe way for children to obtain the vitamin. To reduce the risk for skin cancer, it is important for children to wear sunscreen when playing outdoors. Because sunscreen blocks the absorption of Vitamin D, even children who spend a great deal of time outdoors may not meet their Vitamin D needs.
In addition, dieting and fasting to be thin may also harm nutrition and bone health. As a result, many children — especially adolescents — may not get adequate levels of Vitamin D. For children and teens to safely get the Vitamin D their bodies need, it may be helpful to take Vitamin D supplements. Talk to your doctor about whether Vitamin D supplements are needed.
Sports and exercise are healthy activities for people of all ages. Weight-bearing exercise during the teen years is essential to reach maximum bone strength. Examples of weight-bearing exercise include walking and running, as well as team sports like soccer and basketball.
Occasionally, a female athlete who focuses on being thin or lightweight may eat too little or exercise too much. Young women who exercise excessively can lose enough weight to cause hormonal changes that stop menstrual periods (amenorrhea). This loss of estrogen can cause bone loss at a time when young women should be adding to their peak bone mass. It is important to see a doctor if there have been any menstrual cycle changes or interruptions.
Several groups of children and adolescents are at greater risk for poor bone health, including:
- Premature infants and infants with low birth weight who have lower than expected bone mass in the first few months of life.
- Children who take medications, such as steroids, to treat respiratory diseases like asthma.
- Children who have cystic fibrosis, celiac disease, and inflammatory bowel disease. These conditions make it difficult for the body to absorb nutrients appropriately.
- Adolescent girls who have minimal, delayed, or irregular menstrual cycles because of strenuous athletic training, emotional stress, or low body weight.
- Children with cerebral palsy and other conditions that place limits on physical activity, especially those who take chronic medications for seizure control.
- Children and adolescents who lead inactive, sedentary lifestyles.
Childhood obesity may also play a role in reducing bone density, but more research is needed to separate the roles of other factors including diet, race, ethnicity, lifestyle, and sun exposure.
Research is currently being done on ways to maximize peak bone mass in children but, for now, parents and children alike can benefit from the following suggestions:
- Make sure you get enough calcium and Vitamin D throughout your life.
- Exercise regularly and choose weight-bearing activities like walking and running.
- Eat a healthy diet and lead a healthy lifestyle.
- Do not smoke. Cigarette smoking often starts in childhood and has a harmful effect on reaching peak bone mass.
Source: Recommended Dietary Allowance for calcium from the Food and Nutrition Board (FNB) at the Institute of Medicine of the National Academies (formerly National Academy of Sciences).
Reviewed by members of POSNA (Pediatric Orthopaedic Society of North America)
The American Academy of Orthopaedic Surgeons
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