Calcium and iron intakes of adolescents in Malaysia and their relationships with body mass index (BMI): findings from the Adolescent Nutrition Survey 2017

Introduction: Adolescent health is a priority considering they represent the future generation. Data from the Adolescent Nutrition Survey 2017 were analysed to determine the prevalence of micronutrient inadequacy, particularly calcium and iron, and the relationship with body mass index (BMI) among Malaysian secondary school students. Methods: This cross-sectional study included students aged 13 to 17 years old studying at public and private schools. Twenty-four hours dietary recall via face-to-face interview was conducted by trained nutritionists to obtain data on dietary intake. For nutritional status, BMI-for-age z-score (BAZ) was analysed using WHO Anthroplus software. Results: From 999 respondents, 449 were boys and 550 were girls. Overall findings indicated that both boys and girls had inadequate intakes of calcium and iron in their daily diet. Mean intakes of calcium (695.7±463.2 mg/day) and iron (23.4±21.0 mg/day) were higher among boys aged 16 to 17 years old. Mean intake of iron were higher among the older age groups. Majority of the respondents (boys: 94%; girls: 97%) did not meet the recommended nutrient intake (RNI) for calcium and more than half (boys: 50%; girl: 80%) did not achieve the RNI for iron. Current findings also found significant positive but weak correlations between calcium (r=0.112, p=0.001) and iron (r=0.084, p=0.008) intakes with BMI-for-age. Conclusion: BMI-for-age was related to calcium and iron intakes among secondary school students in Malaysia. Thus, intervention strategies should focus on early screening and nutrition education on food choices of high calcium and high iron contents, including iron supplementation programmes, if needed.