Increasing dietary calcium intake of children and their parents: a randomised controlled trial

OBJECTIVE: Approximately 25 % of Canadian children aged 4-8 years fail to meet the recommended dietary allowance (RDA) of calcium (Ca). Young children's food choices are primarily determined by their parents. No interventions have directly targeted parents as a medium through which to increase children's Ca consumption. This study compared the effectiveness of a Ca-specific intervention targeted towards parents, with generic dietary advice on the Ca consumption of children aged 4-10 years. DESIGN: A parallel two-arm randomised controlled trial was conducted. SETTING: The study was conducted across Canada. Both conditions received information on the RDA of Ca and an index of intake requirements. Material sent to the intervention condition included behavioural strategies to increase dietary Ca consumption, information on the benefits of dietary Ca intake and messages addressing perceived barriers to the consumption of Ca-rich foods. PARTICIPANTS: A total of 239 parents (93 % mothers) of children aged 4-10 years who consumed less than the RDA of Ca were randomly assigned in a 1:1 allocation ratio. RESULTS: There was a significant increase in total Ca intake and Ca from dairy for children at weeks 8, 34 and 52 (P ≤ 0·001) in both conditions. Parental Ca intake and amount spent on dairy products did not significantly increase following the intervention. CONCLUSIONS: Provision of daily Ca requirements with regular reminders could impact parents' delivery of Ca-rich foods to their children. This finding is important for public health messaging as it suggests that parents are a potent medium through which to promote Ca intake in children.