July 2019


An estimated 1 billion people, including 35 million babies, do not consume sufficient amounts of iodine. Almost 18 million of these babies are mentally impaired as a consequence.

Nearly 2 billion people suffer from anemia, over half of which is due to iron deficiency. Anemia is a condition that can cause complications in pregnancy, low birth weight, and infant and maternal deaths.

Table salt is a universal condiment, present in the diets of nearly every population. Therefore, addition of essential micronutrients to salt is an effective way to reduce micronutrient deficiencies. Salt iodization is considered one of the most successful health interventions of the 20th century, reaching 86% of all households globally. However, ensuring sufficient levels of iodine in salt, and thus adequate iodine consumption, remains a challenge. Recently, technology to include iron in salt has been developed by Nutrition International and the University of Toronto.

Double Fortified Salt

Double Fortified Salt (DFS) contains both iodine as potassium iodate, and iron as ferrous fumarate, compounds that were found to be most suitable for this application in terms of nutrient stability and product taste. The interaction between iron and iodine is reduced or eliminated through encapsulation of the iron. Mixing is critical to ensure quality and compliance of DFS. Although iodine is typically applied to salt using a spray drying technique, which facilitates a relatively homogenous distribution in salt, encapsulated iron is added by dry mixing, which results in a heterogeneous distribution.

Preliminary studies also indicate cost-effectiveness of this intervention at scale. Production of DFS is estimated to cost US $0.18 – 0.20 per person, per year, with a benefit-to-cost ratio calculation for anemia reduction around 2.4 to 1 or better.

Measuring Iron and Iodine in DFS with iChecks

To support the implementation of DFS, BioAnalyt developed a sample preparation protocol to enable reliable measurement of the concentrations of both iron and iodine in a single salt sample. iCheck Iodine and iCheck Iron are both portable single-wavelength photometers, pre-calibrated for quantitative measurement of iodine in salt and iron in multiple food matrices, respectively. iCheck Iodine was already developed to specifically measure iodine in table salt as potassium iodate. iCheck Iron has the capability to measure intrinsic iron and added iron as ferrous fumarate, ferrous sulfate, NaFeEDTA, and ferric pyrophosphate in many food matrices.

To ensure reliable results with iCheck Iron, DFS samples require a customized sample preparation protocol. Samples should be diluted in a hydrochloric acid solution to facilitate solubilization of the ferrous fumarate. Then, samples are heated to release the iron compound from its stearin encapsulation. Download our application paper here to learn more.

As always, the BioAnalyt team is on stand-by to answer your technical questions, provide product support, or assist you with ordering iChecks and test kits. Contact us today!

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