Presentation by : Omar Dary Place: World Nutrition – 2012 Rio de Janeiro, Brazil 29-April-2012 Monitoring Salt and Iodine Intakes is a Critical Issue to Adjust Salt Fortification Programs

Abt Associates | pg 2 OD Content 1.The Dietary Reference Intakes (DRI) of iodine 2.The misinterpretation of the 100 µg/L cut-off point for urinary iodine to assess appropriate iodine intake 3.Advantage of estimating the 24-h iodine excretion 4.Estimating efficacious and safe iodine intakes for the whole population 5.Transforming those intakes in iodine contents in salt 6.Conclusions

Abt Associates | pg 3 OD Iodine Dietary Reference Intakes (µg/day) Figure modified from Institute of Medicine, the Academies of Science, USA Iodine: µg/d 1500 mg/d Nasalt: 3.7 g/d Values are for children 6-9 years old

Abt Associates | pg 4 OD Median Urinary Iodine Concentration in 6-12 y old children in Germany Source: Johner et al. Br J Nutr Authorizing food industry to use iodized salt

Abt Associates | pg 5 OD Iodine and sodium intakes in 6-12 y old children in Germany (Medians) Parameter UIC (µg/L)11098 UIE (µg/d)8684 Iodine Intake (µg/d) *10199 % < EAR17 %16 % Source: Johner et al. Br J Nutr * Assuming that 85% of iodine and 90% sodium intakes are excreted in urine Parameter U-Na-Excretion (g/L) U-NaCl-Excretion (g/d) Salt Intake (g/d) * References: EAR iodine = µg/d; UL salt = g/d

Abt Associates | pg 6 OD Sources: USA-NHANES; UIC – , except non-pregnant and pregnant women , Caldwell et al. Thyroid 2011; 21: 419; body weight , McDowell et al., Anthropometric reference data for children and adults; National Health Statistics Report 2008; 10. UIE (ug I/d) estimated by multiplying the reported UIC (ug I/L) for the calculated urinary volume of each age- and gender group, based on body weight: Urinary volume (L/d) = L/h.kg x 24 h/d x wt (kg) – from IOM/ Academies of Sciences of the USA: Dietary Reference Intakes for iodine and other nutrients. National Academy Press UIC and estimated UIE in the USA

Abt Associates | pg 7 OD Ensuring iodine efficacy for everyone: “adjusted” EAR VariableCh 9-13M 19-30F Pregnant Women Lactating women EAR (µg I/d) Energy (kcal/d) µg I /100 kcal Conclusions: The groups at the highest risk of iodine inadequacy are the pregnant and lactating women. For protecting the whole population the adult females should have an iodine intake 1.87 times higher than their corresponding EAR value of iodine: 95 x 1.87 = 178  180 µg/d. Reference to F years old

Abt Associates | pg 8 OD Ensuring iodine safety for everyone: “adjusted” UL VariableCh 1-3Ch 9-13M 19-30F Pregnant women UL (µg I/d) Energy (kcal/d) µg I/ 100 kcal Reference to F years old Conclusion: The groups at the highest risk of receiving excessive amounts of iodine are the children 1-3 years old. For protecting the whole population the adult females should have an iodine intake 0.41 times lower than their corresponding UL value of iodine: 1,100 x 0.41 = 451  500 µg/d.

Abt Associates | pg 9 OD Potential of “fortifiable” salt (hypothetical) Salt sourcesChinaJapanUSA Diet 10 %30 %50 % Processed foods 12 %60 %35 % Discretionary salt (cooking + table) 78 %10 %15 % Proportion of fortifiable salt 90 %70 %50 % Conclusion: Both discretionary salt and processed foods should be iodized; depending only on discretionary salt would be insufficient for developed countries and countries in epidemiological and economic transition. Based on data from Elliot and Brown, “Salt intakes around the world”. WHO, Diet salt is assumed from fish, meat, poultry, milk, cheese, ham, margarine and tomatoes.

Abt Associates | pg 10 OD Estimating efficacious and safe iodine contents in “fortifiable” salt Country Salt intake (g/d)* “Fortifiable” salt (g/d)** Average iodine content (mg I/kg) *** P-10P-90P-10P-90 EfficaciousSafe PRC-South USA ¶ Japan PRC-North * Using the adult females as the reference groups, and as the “average” population group. Data from Elliot and Brown, “Salt intakes around the world”. WHO, ** Proportions of “fortifiable” salt in prior table. *** Efficacious: “adjusted” EAR at P-10; Safe: “adjusted” UL at P-90. And, assuming that the only source of iodine is the salt. ¶ If one assumes that USA received 50% iodine through the diet (milk mainly), then the iodine content in salt could be reduce by half; i.e. around 40 mg I/kg.

Abt Associates | pg 11 OD Conclusions 1.UIC (µg/L) is an unreliable indicator to estimate iodine intake; it is preferable using UIE (µg/d) 2.Intake of iodine from salt and sodium are directly correlated with the energy intake of each person 3.Estimation of daily excretion of both iodine and sodium (NaCl) is needed to design efficacious and safe iodization programs 4.Both processed foods and discretional salt should be iodized in a content that is proportional to the sodium intake from these sources in each population