Testing Iodine Content of Salt:Kit and Home Based Methods Ms Cadi Parveen Banu Institute of Nutrition and Food Science, University of Dhaka
Salt Iodization Program in BangladeshBackground• During the period 1962-1964, the first National Nutrition Survey was carried out in Bangladesh ( the then East Pakistan) identified prevalence of hyper endemic goiter .• The second nutrition survey was organized in rural areas of Bangladesh in 1975-76.Both the survey reported that average prevalence of goiter was found to be 28.9% and 13.8% in 1962-64 and 1975-76 respectively
• The first National Goiter Prevalence study of Bangladesh was conducted in 1981 by the Institute of Public Health Nutrition (IPHN).• During survey, only goiter was assessed; no data on cretinism or other consequences were collected.• The survey revealed, a wide prevalence of goiter to varying degree all over the country with an average national prevalence rate of 10.51% and some areas of high endemicity of goiter (e.g. Jamalpur, Rangpur).
Law for Universal Salt Iodization• In 1989 Government of Bangladesh passed a law making it mandatory the universal iodization of all edible salt.
IDD Situation of Bangladesh According to National Survey,1993
• A by-law was passed in 1994 only then substantial improvement was made in the infrastructure of universal salt iodization (USI).
Universal Salt iodization• For the assessment of iodine content of salt USI survey was conducted in 1996 and 1999• During the period of 1996-99, the percentage of adequately iodized salt at HH level (≥15 ppm) was maintained at 54 to 55%.• At the factory level 4.8% salt had adequate iodine (45-50 ppm).
IDD Situation of Bangladesh According to National Survey,1999
IDD SURVEY,2004-5• The overall prevalence of iodine deficiency was 33.8% and 38.6% among the children and women respectively.• High Prevalence of IDD among the children and women was observed in some selective areas.
Methods for Testing Iodine in Salt• Qualitative Home based Testing Kit• Quantitative Titration
Principle• Iodine is added in the form of KIO3 to iodize the salt in Bangladesh.• Iodine can be set free from KIO3 in iodized salt by addition of acid.• The liberated iodine forms violet color complex with starch.
Home based method: testing iodine• Take one tea spoon of household salt• Mix with 5 grains of cooked rice• Then add a few drops of lemon juice• Salt will turn purple if it contains iodine• There will be no color change if it does not
Testing Kit: Developed by IFST, BCSIR• A leveled spoonful of salt is taken in a marked transparent plastic container• A small amount of working solution (bottle 2) is added to the salt in the container• The container is swirled till the salt dissolves• Then more working solution will be added to bring the volume up to the mark of the container and mix thoroughly.
• About 10-15 ml of salt solution will be taken in a cup.• A piece of paper strip will be dipped in the salt solution.• Allow to develop the violet color (7-10 sec)• Comparing the developed color with the supplied colored chart.• Read out the amount of iodine in salt.