Dietary salt intake assessed by 24 h urinary sodium excretion in Australian schoolchildren aged 5–13 years

Abstract

AbstractObjectiveTo measure total daily salt intake using 24 h urinary Na excretion within a sample of Victorian schoolchildren aged 5–13 years and to assess discretionary salt use habits of children and parents.DesignCross-sectional study.SettingCompleted within a convenience sample of independent primary schools (n9) located in Victoria, Australia.SubjectsTwo hundred and sixty children completed a 24 h urine collection over a school (34 %) or non-school day (66 %). Samples deemed incomplete (n18), an over-collection (n1) or that were incorrectly processed at the laboratory (n3) were excluded.ResultsThe sample comprised 120 boys and 118 girls with a mean age of 9·8 (sd1·7) years. The average 24 h urinary Na excretion (n238) was 103 (sd43) mmol/24 h (salt equivalent 6·0 (sd2·5) g/d). Daily Na excretion did not differ by sex; boys 105 (sd46) mmol/24 h (salt equivalent 6·1 (sd2·7) g/d) and girls 100 (sd41) mmol/24 h (salt equivalent 5·9 (sd2·4) g/d;P= 0·38). Sixty-nine per cent of children (n164) exceeded the recommended daily Upper Limit for Na. Reported discretionary salt use was common: two-thirds of parents reported adding salt during cooking and almost half of children reported adding salt at the table.ConclusionsThe majority of children had salt intakes exceeding the recommended daily Upper Limit. Strategies to lower salt intake in children are urgently required, and should include product reformulation of lower-sodium food products combined with interventions targeting discretionary salt use within the home.