Evaluation of Iodine Content in Table Salt Consumed in Democratic Republic of Congo

Abstract

Background DR Congo has adopted universal salt iodization to reduce disorders due to iodine deficiency. Since 1994, only iodized salt can be imported, but there is currently no routine monitoring of the iodine content of distributed salt. It is therefore unclear if iodine deficiency remains a health problem, particularly in pregnant women. Objective To evaluate the iodine content of salt in households of pregnant women in Lubumbashi. Methods We conducted a survey of the iodine content of salt consumed by 375 women presenting at prenatal consultations in three socially different areas of Lubumbashi: urban, semiurban, and rural. The women were questioned about where they purchased salt, how it was packaged, and how they stored the salt, and each woman provided a sample of salt for determination of its iodine content by the iodometric method. Results Most women (84.3%) bought salt in the public markets, mainly in bulk (93.6%); 80.0% stored salt in plastic boxes. The median iodine content was 27.5 ppm (IQR, 16.0–38.1) in urban areas, 19.0 ppm (IQR, 7.4–31.7) in semiurban areas, and 20.1 ppm (IQR, 5.3–31.7) in rural areas. The iodine content was less than 15 ppm (minimum threshold) in 36.3% of samples, including 13.9% without any detectable iodine. The iodine content was above 40 ppm (maximum limit) in 18.9% of samples. Only 44.8% of salt samples had adequate iodine content. Conclusions The population of Lubumbashi remains at risk for hypothyroidism and hyperthyroidism. An effective and regular system for the control of iodine content in distributed salt is needed in DR Congo.