The iodized salt programme in Bangalore, India provides adequate iodine intakes in pregnant women and more-than-adequate iodine intakes in their children

Abstract

Objective: To compare the iodine status of pregnant women and their children who were sharing all meals in Bangalore, India. Design: A cross-sectional study evaluating demographic characteristics, household salt iodine concentration and salt usage patterns, urinary iodine concentrations (UIC) in women and children, and maternal thyroid volume (ultrasound). Setting: Antenatal clinic of an urban tertiary-care hospital, which serves a low-income population. Subjects: Healthy pregnant women in all trimesters, aged 18-35 years, who had healthy children aged 3-15 years. Results: Median (range) iodine concentrations of household powdered and crystal salt were 55·9 (17·2-65·9) ppm and 18·9 (2·2-68·2) ppm, respectively. The contribution of iodine-containing supplements and multi-micronutrient powders to iodine intake in the families was negligible. Adequately iodized salt, together with small amounts of iodine in local foods, were providing adequate iodine during pregnancy: (i) the overall median (range) UIC in women was 172 (5-1024) µg/l; (ii) the median UIC was >150 µg/l in all trimesters; and (iii) thyroid size was not significantly different across trimesters. At the same time, the median (range) UIC in children was 220 (10-782) µg/l, indicating more-than-adequate iodine intake at this age. Median UIC was significantly higher in children than in their mothers (P = 0·008). Conclusions: In this selected urban population of southern India, the iodized salt programme provides adequate iodine to women throughout pregnancy, at the expense of higher iodine intake in their children. Thus we suggest that the current cut-off for median UIC in children indicating more-than-adequate intake, recommended by the WHO/UNICEF/International Council for the Control of Iodine Deficiency Disorders may, need to be reconsidered. Key words Iodine Iodized salt Urinary iodine concentration Pregnant women Children IndiaUniversal salt iodization (USI) is a mass fortification approach that is intended to cover the iodine requirements of all individuals in the population; it is estimated that 128 countries have established iodized salt programmes (1) .As USI programmes mature in many countries, greater emphasis is being placed on ensuring that USI meets the increased needs of pregnant women because of the risk of irreversible fetal brain damage due to iodine deficiency (2,3) . Another focus of mature programmes is the need for careful monitoring to avoid not only iodine deficiency but also iodine excess (1) . Median urinary iodine concentration (UIC) in school-aged children (SAC) and household access to adequately iodized salt based on national standards are routinely used as the primary indicator of the impact of USI programmes. However, the iodine requirement of SAC is disproportionately lower than that of pregnant women, which leaves only a narrow intake range to meet the needs of pregnant women without leading to more-than-adequate intake in children according to the current UIC cut-off of 200 μg/l (4) .

Adequacy of iodisation of salt at the household level and its associated factors in a rural sub-centre area of Bangalore Urban District, Karnataka, India: a cross-sectional study

“…This higher crushed salt preference was also observed in our study. 12 Limitations which can be considered in our study include observer bias in inference of MBI kit results. Some household members predominantly involved in cooking were not involved in purchase of cooking salt and hence could lead to errors in data provided.…”

Maternal nutrition and the risk of congenital malformations in the tea garden community of Assam, Northeast India

“…In their recent review, Yadav et al reported that 59.5-95% of pregnant women were consuming adequately iodized salt in India, 21 but the condition is skewed in rural and tribal communities. 22,23 While some studies indicate widespread iodine deficiency among pregnant women of India, 13,23,24 others report of adequacy. 12,25,26 While evaluating iodine adequacy among healthy women of the community, we observed an overall deficiency (117.94 mg/l).…”

Iodine Supplementation in Pregnancy and the Dilemma of Ambiguous Recommendations

“…Other investigators have reported different results, with a higher median UIC in children than in pregnant women [20,21]. In these studies from Thailand and India [20,21], the children and pregnant women shared one or more meals, but the time and location of spot urine sampling may have differed. Moreover, the pattern of supplement intake was different compared to our Danish study.…”

“…3) [16]; however, iodine supplement use was much more frequent among pregnant women than among male partners and children [16]. Other investigators have reported different results, with a higher median UIC in children than in pregnant women [20,21]. In these studies from Thailand and India [20,21], the children and pregnant women shared one or more meals, but the time and location of spot urine sampling may have differed.…”