Salt-reduction strategies may compromise salt iodization programs: Learnings from South Africa and Ghana

The effect of sodium restriction on iodine prophylaxis: a review

“…Conversely, 9 studies did not find a worsening in the iodine status in the setting of low sodium intake. These results were obtained in the US population [20], in Italian adults [36,39], in a post hoc analysis of a Dutch study [40], in adults and children living in Northern China [27], in Australia (especially in Native Australians) [35,37], and among South African and Ghanaian adults [34,43]. In one manuscript evaluating young women in Samoa [38], no relationship was found between urinary sodium and iodine excretion, but it has to be highlighted that in the Pacific region the level of salt consumption (iodized and non-iodized) is largely unknown, and data on iodine nutrition are sparse.…”

“…As shown in Table 1, out of the 13 papers selected, 7 were population-based studies, 3 simulation studies, 2 RCTs and 1 a cohort study. Based on the study design and the number of subjects involved, 3 population studies [20,42,43], 2 simulation studies [33,36] and one RCT [27] may be classified as high-quality studies in the present review.…”

“…Selection criteria included manuscripts concerning dietary advice/education/habit, food analysis, iodine intake, iodine excretion, iodine status, salt consumption, sodium excretion, and dietary sodium restriction/reduction. Then, a quantitative analysis was performed, and 13 papers [20,27,[33][34][35][36][37][38][39][40][41][42][43] (7 population studies [20,34,35,38,[41][42][43], 3 studies based on a simulation model [33,36,37], 2 randomized controlled trials (RCTs) [27,40], 1 cohort study [39]) presented both inclusion criteria and relevant results to be discussed considering the aim of the present review. In detail, studies involving highly selected categories such as pregnant women (at higher risk of both iodine deficiency and hypertension), and articles not dealing with iodized salt or made in countries not using it (for example, South Korea), were not considered.…”

The Role of Multiply-Fortified Table Salt and Bouillon in Food Systems Transformation

“…With the global effort to reduce salt intake to tackle rising NCD incidence, there is concern that this trend is incompatible with the utilization of salt as a fortification vehicle. Reducing salt intake could: (i) lower the effectiveness of salt fortification programs, resulting in an increased incidence of micronutrient deficiency, particularly iodine at present [ 54 , 55 ] and/or (ii) reduce the effectiveness of salt and salt-containing condiments for additional micronutrients beyond iodine [ 56 ]. Additionally, fortified salt or bouillon may be seen to have greater health benefits by a consumer (e.g., positive consumer bias toward foods with front of pack nutrient claims [ 57 ]) encouraging increased consumption and a higher intake of salt [ 58 ]; however, there is no clear evidence to support the concern that fortification leads to higher consumption of the vehicle.…”

“…The public health goals of reducing salt intake while fortifying salt to increase micronutrient intake (e.g., through salt iodization) are indeed compatible, given that the concentration of micronutrients can be adjusted as the intake of salt/bouillon is reduced (further referred to in the paper as titration) [ 54 , 59 ]. Success will require continuous monitoring of salt intake (e.g., through 24-h urinary sodium measures and dietary intake surveys) and the level of micronutrient intake (e.g., comprehensive dietary assessments to understand the contribution of iodine from fortified or other dietary sources) to enable titration of the fortificants in salt to the level required (i.e., to reduce the prevalence of inadequate micronutrient intake to the greatest extent possible while minimizing the proportion of the population with intake above the tolerable upper intake level) [ 55 , 60 ]. While there appears to be significant consensus on the compatibility of micronutrient fortification and sodium reduction initiatives [ 54 , 58 , 59 , 61 , 62 ], there are few reported examples in practice, likely due to few countries successfully reducing sodium intake [ 22 ].…”