Effectiveness of Iodine Supplementation on Iodine Nutrition of Thai Pregnant Women

Abstract

Ministry of Public Health Thailand has a national policy for iodine supplementation to pregnant women that still need to be followed up. This study aimed to analyze the effectiveness of iodine supplementation in pregnant women and investigate the amount of iodine tablets and iodized salt consumption in pregnant women as well. Study areas were selected from national iodine surveillance 2010-2015 including 13 provinces with a history of sufficient iodine intake and 13 provinces with a history of inadequate iodine intake. Three hundred pregnant women in each province were collected their urine samples for iodine concentration analysis at the first visit of antenatal care before supplementation and at 36-38 weeks of gestational age.  Results found median urine iodine of 4,395 pregnant women before and after supplementation were 127.3 (74.4-198.1) and 156.7 (96.0-255.9) micrograms/liter, a difference with statistical significance (p<0.01). 57.8% of pregnant women took iodine tablets every day, 32.9% took some days and 9.2% did not take it. Reasons for not taking tablets were forgetfulness, not receiving, running out of tablets, and side effects. 83.6% used iodized salt, while 32.8% used iodized salt only. Reasons for not using iodized salt were a change in food taste, unaffordable cost, unavailability, and lacking knowledge of iodized salt. This study showed that iodine supplementation could solve iodine deficiency in pregnant women. Knowledge and increased recognition of iodine tablet intake and iodized salt consumption continuously are recommended for further actions.