Iodine in commercial edible iodized salts and assessment of iodine exposure in Sri Lanka

Abstract

BackgroundIodine is an essential micronutrient used by the thyroid gland in the production of thyroid hormones. Both excessive and insufficient iodine intakes can cause thyroid diseases thus harmful to the human body. Inadequate iodine intake by human body causes Iodine Deficiency Disorders (IDD) and hypothyroidism. Excessive iodine intake causes Iodine Induced Hyperthyroidism (IIH). Universal Salt Iodization (USI) is the most effective way of preventing IDD. This study determined the concentrations of iodine species in commercial edible salt products, the stability of iodine at different conditions and iodine exposure at the consumer level.MethodsThe iodine contents of six commercial edible iodized salts were determined qualitatively and quantitatively for both iodide and iodate. Thereafter, the first three products of highest iodine contents, the stability of iodide at exposed to air and heat was measured after 24 hours. Risk assessment of exposure was done at four levels considering the WHO estimation.ResultsResults revealed that all of the salt products have excess iodine that is above the fortification level of 15–30 mg kg−1 level in Sri Lanka. Iodide stability was reduced at the average percentages of 13.1, 10.7 and 11.3. The iodate loss percentages were 0, 5.7 and 0 at open air. The iodide loss percentages at the temperature of 50 °C were 4.6, 7.8 and 8.6 while at 100 °C, loss percentages were 11.1, 11.4 and 15.9 for the same salt products. The iodine exposure at lower consumption during cooking ranged 244.4–432.2 μg/day while 325.9–576.3 μg/day for medium consumption, 407.4–720.4 μg/day for moderate high salt consumptions and 488.8–864.4 μg/day for high salt consumptions. As a total 95.8 % cases can cause IIH and only 4.1 % of them can provide optimal iodine nutrition in a population. Iodine exposure without cooking ranged 305.5–540.3 μg/day for low salt consumption, 407.4–720.4 μg/day for medium consumption and 509.2–900.5 μg/day for moderate high consumption and 611.1–1080.6 μg/day for high salt consumptions.ConclusionsAll of the incidents (100 %) of consumption without cooking at the household level can cause excessive iodine intake and IIH in a population.

The Selection of the Optimal Impregnation Conditions of Vegetable Matrices with Iodine

“…It was found that the total iodine content after drying the samples was most strongly correlated with the degree of hydration (r = 0.903) and the temperature of the impregnated samples (r = 0.99). This is also confirmed by previous studies [ 30 , 56 , 59 , 60 ]. The lowest stability of iodine was shown for samples impregnated at 4 °C.…”

“…Impregnation time was also a factor affecting iodine content (r = 0.765). However, the significance of this factor depended on the degree of hydration and even more on the impregnation temperature [ 30 , 55 , 60 , 62 , 65 ]. The use of 1:4 hydration and impregnation temperature of 4 °C yielded total iodine ranging from 78 to 97%.…”

Electrochemical investigation and amperometry determination iodate based on ionic liquid/polyoxotungstate/P-doped electrochemically reduced graphene oxide multi-component nanocomposite modified glassy carbon electrode

“…The content of iodate in the solution was determined by the iodometric titration method as a standard method according to the procedure given in the previous literature. 92 The measurements were performed using the standard addition method, by SWV in the potential range from 0 to −1.0 V, scan rate 50 mV s −1 .…”

“…The content of iodate in the solution was determined by the iodometric titration method as a standard method according to the procedure given in the previous literature. 92 The measurements were performed using the standard addition method, by SWV in the potential range from 0 to À1.0 V, scan rate 50 mV s À1 . The standard solutions of iodate were injected into the real samples to check the recovery percent of added iodate (found value/intrinsic value).…”

Iodine Nutrition: Iodine content in iodized salt in Sri Lanka and the effect of temperature and storage conditions on the stability

“…The iodide content was measured using an iodide combination electrode [23]. Salt (2 g) was dissolved in 10 ml of distilled water.…”