Dietary calcium intake was found to have a significant positive association with total bone mineral density (BMD) in adolescents, according to results from a cross-sectional study published in Endocrine Connections.
Adequate calcium intake during adolescence is critical for bone health in adulthood, but the optimal calcium intake to maintain skeletal growth remains unclear. In addition, the influence of dietary calcium intake on BMD is not yet fully understood.
To establish whether self-reported dietary calcium intake has an effect on BMD, data from 10,092 US children and adolescents from the National Health and Nutritional Examination Survey (NHANES) database were analyzed. Overall, 57.14% of the individuals in the study cohort were male, 61.47% were white, 14.57% were black, and 11.36% were Mexican American. Individuals aged 8 to 19 years with complete dietary calcium intake and total BMD data were included.
Dietary calcium intake was assessed with an in-person 24-hour dietary recall session. Proxy-assisted interviews were conducted for children ≤11 years of age. Total BMD was measured by dual-energy x-ray absorptiometry scans, and physical activity and calcium supplement use for the 30 days before the in-person interview were self-reported. Serum calcium was measured for all individuals.
Among the 5 quintiles of dietary calcium intake, age, body mass index, income poverty ratio, serum calcium level, total BMD, sex, race/ethnicity, physical activity, and calcium supplement use were all significantly different (P <.0001). After controlling for potential confounding factors, a significant positive association between dietary calcium intake and total BMD was observed. The strongest association was observed in white individuals aged 12 to 15 years, in Mexican Americans aged 8 to 11 or 16 to 19 years, and in other races aged 16 to 19 years. The observed trend was significant in all groups except individuals of other races aged 8 to 11 years.
Inflection points were found in the following groups: children aged 12 to 15 years, females, and black individuals. For these groups, total BMD decreased when the dietary calcium intake was more than 2.6 to 2.8 g/d.
These findings indicate that dietary calcium intake positively correlates with total BMD, and that race/ethnicity, sex, and age affect optimal calcium supplement intake. A large proportion of children and adolescents in the United States may attain greater bone mineral density if they increase their dietary calcium intake within safe limits.
Limitations to the study included its observational nature and reliance on individual recall and self-reporting. Further examination of the effect of higher dietary calcium intake on total BMD in female adolescents, black adolescents, and adolescents aged 12 to 15 years is warranted.
Pan K, Zhang C, Yao X, Zhu Z. Association between dietary calcium intake and BMD in children and adolescents. Endocr Connect. 2020;(9):194-200.