November 2006: Calcium Intake in Adolescents

According to Merriam-Webster’s Medical dictionary, osteoporosis, one of the most preventable diseases, results from “a decreased bone mass with decreased density and enlargement of bone spaces producing porosity and brittleness”. Using dietary interventions, such as consuming calcium rich foods and exercising can lower one’s risk of developing osteoporosis later on in life. However, even with a great variety of foods that contain calcium, including calcium-fortified foods, calcium consumption in the US is still below the recommendations. Researchers are working tirelessly to find the reasons why calcium consumption is so low in order to provide solutions. Most recently, a greater push to promote calcium has shifted from older adults to adolescents. Currently, the American Academy of Pediatrics recommends between 1200-1500 mg/d of calcium for pre-adolescents and adolescents. Adolescents is the prime time to build peak bone mass. Furthermore, it is the optimal time to instill life-long healthy habits of consuming calcium in order to prevent diseases or disorders like osteoporosis.

Many studies have concluded that calcium consumption is below the Adequate Intake (AI) of calcium (1300mg/d) for youth this age. Researchers are trying to determine the causes for calcium intake to be below the recommended level. For example, one study looked at the consumption of calcium, dairy, and milk compared to that of socioenvironmental, personal, and behavioral factors. Whereas another study examined the consumption of calcium from non-dairy diets using data from the 2001-2002 National Health and Nutrition Examination Survey. By learning about the causes of sub-par calcium intakes, researchers and nutrition educators can provide solutions to the public, especially when diseases like osteoporosis can be highly prevented.

The first study researched the intake of calcium, dairy, and milk in adolescents attending either middle school or high school in Minneapolos/St. Paul, MN. In this study, they looked at socioenvironmental, personal, and behavioral factors in relationship to dietary intake of calcium, dairy, and milk. Socioevnironmental factors included, but not limited to, social support for health eating, parental presence at meal, family socioeconomic status, and milk served at meals. Personal factors such as demographics, self-efficacy to make healthy food choices, taste preference for milk, and lactose intolerance were some of the variables analyzed. Behavioral factors looked at breakfast, lunch, and dinner intake, fast-food intake, soft drink intake, unhealthful weight control behaviors, and sports involvement. Larson et al concluded that adolescents were not consuming adequate amounts of calcium, dairy, or milk as a result of several of these variables. Further recommendations were made in the study to increase the consumption of calcium, dairy, and milk for this particular age group. (Larson N, Story M, Wall M, Neumark-Sztainer D. Calcium and Dairy Intakes of Adolescents Are Associated with Their Home Everonment, Taste Preferences, Personal Health Beliefs, and Meal Patters. J Am Diet Assoc. 2006;106:1816-1824. Accessible at www.adajournal.org)

The second study analyzed the patterns of calcium consumption in a non-dairy diet from adolescents aged 9-18. Data was taken from the 2001-2002 National Health and Nutrition Examination Survey (NHANES). NHANES surveyors used a 24-hour recall to determine the diet composition of the participants. Using the 24-hour recall data of non-dairy consuming adolescents, the authors used linear programming models to determine maximal calcium intake. The study found that without dairy foods, adolescents will find great difficulty in meeting the adequate intake (AI) for calcium. Further recommendations were made to increase calcium intake by including other factors which increase the bioavailability of calcium and utilization of calcium. (Gao X, Wilde P, Lichtenstein A, Tucker K. Meeting Adequate Intake for Dietary Calcium without Dairy Foods in Adolescents Aged 9 to 18 years (National Health and Nutrition Examination Survey 2001-2002).J Am Diet Assoc. 2006; 106: 1759-1765. Accessible at www.adajournal.org )