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Most US preschoolers consume too much sodium

September 4, 2013

79% of children aged 1–3 years and 87% of those aged 4–5 years exceed the recommended upper intake level of potassium, reports a new US study.

To investigate the intake of sodium and potassium during the establishment of dietary patterns before entry to school, intake data were analyzed among 3 groups of participants: 699 infants aged 7–11 months, 2882 children aged 1–3 years and 1389 children aged 4–5 years (1). Based on the data from a large US intake survey (NHANES 2003–2010), the analysis showed that 79 percent of children aged 1–3 years and 87 per-cent of those aged 4–5 years exceeded their Tolerable Upper Intake Levels (ULs) for sodium; among non-Hispanic black children, the estimates were 84 percent and 97 percent, respectively. However, in terms of reaching adequate intake for potassium, 97 percent of infants’ potassium needs were met, but only 5 percent of children aged 1–3 years, and 0.4 percent aged 4–5 years met their adequate intakes. Breastfed infants and children consumed, on average, less sodium than those who were not breastfed.


The researchers commented that excess sodium and inadequate potassium intake are related to hyper-tension, a major risk factor for cardiovascular diseases, the leading causes of death in the United States (2). Evidence from human studies, including randomized controlled trials and meta-analyses (3), indicate a pos-itive dose-response relation between dietary sodium intake and blood pressure, particularly among certain population subgroups, such as non-Hispanic blacks (4). Results from the NHANES 2003–2008 indicated that US children aged 8–18 years consume about the same average amount of sodium per day as adults (3400 mg) and higher sodium intake was associated with higher systolic pressure, particularly among children who were overweight or obese (5). Given that high blood pressure tends to persist with age, early sodium and potassium intake in line with recommendations might help prevent development of later hypertension (6). The finding that breastfed infants consume less sodium than do those who are not breastfeeding merits further investigation.


In 2005, the Institute of Medicine (IOM) established the Dietary Reference Intakes, including Tolerable Upper Intake Levels (ULs) for sodium (2300 mg/d) for adults aged 19–50 years on the basis of a dose-response relation between sodium and hypertension. ULs for children were extrapolated from adult ULs on the basis of averages of median age-specific energy intakes. No UL was set for infants, nor was a UL set for potassium.

References

1. Tian N. et al. Sodium and potassium intakes among US infants and preschool children, 2003–2010. Am J Clin Nutr. Published online August 2013.

2. Roger V. L. et al. Heart disease and stroke statistics - 2012 update: a report from the American Heart Association. Circulation. 2012; 125:e2–220.

3. Cutler J. A. O. E. and Roccela E. J. Dietary salt reduction. In: Whelton P. K. H. J. and Louis G. T., eds. Lifestyle modification for the prevention and treatment of hypertension. New York, NY: Marcel Dekker, 2003:139–159.

4. Weinberger M. H. Salt sensitivity of blood pressure in humans. Hypertension.v 1996; 27:481–490.

5. Yang Q. et al. Sodium intake and blood pressure among US children and adolescents. Pediatrics. 2012; 130:611–619.

6. Tekol Y. Maternal and infantile dietary salt exposure may cause hypertension later in life. Birth Defects Res B Dev Reprod Toxicol. 2008; 83:77–79.