Breast Milk Iodine and Iodine Status of Breast-Fed Infants.

Background: Breast milk is the only source of iodine for exclusively breast-fed infants. Iodine status of breast-fed infants depends on iodine in breast milk and also number of feeding in 24 hours. Iodine deficiency and iodine excess both have bad impact on infant’s health. Objective: To measure the iodine in breast milk and to evaluate iodine status of their breast-fed infants. Materials and method: This observational analytical study was carried out in the department of Biochemistry, Bangabandhu Sheikh Mujib Medical University, Dhaka with active cooperation of Kumudini Women’s Medical College Hospital, Mirzapur, Tangail involving fifty lactating mothers and their exclusively breast-fed infants. Early morning urine and breast milk samples were collected in dry and clean plastic container free from any chemical contamination. Urinary iodine was used as indicator for assessing iodine status. All statistical analyses were done by using SPSS (statistical programme for social science) 12 version software package for Windows. Results: The median (range) urinary iodine concentration of lactating mothers and their breast-fed infants were 225.25 μg/L (61.50-530.00) and 225.75 μg/L (100.50-526.00) respectively. The median (range) breast-milk iodine concentration was 157 μg/L (54.50-431.50) which was more than three times of recommended minimum concentration (50 μg/L). Only 2 (4%) lactating mothers had mild biochemical iodine deficiency (UIE, 50-99 μg/L). There was no biochemical iodine deficiency of breast-fed infants. Iodine in breast milk of lactating mothers was positively correlated with their urinary iodine excretion (p<0.01). Infant’s urinary iodine was positively correlated with iodine concentration in breast milk (p<0.01) and with urinary iodine of lactating mothers (p<0.01). Conclusion: Lactating mothers and their breast-fed infants in this study were iodine sufficient. If iodine content of breast-milk is within normal range, 10-12 numbers of feeding in 24 hours for infants is enough to get sufficient iodine from their mother’s milk.

Thyroid Function and Urinary Iodine Status in Primary School Age Children of the Hills and the Plains of Eastern Nepal.

The aim of this study is to find out the iodine nutrition and thyroid function status of the school age children of Sunsari and Dhankuta districts. A total of 386 urine and 142 blood samples were randomly collected from four schools of above districts to estimate urinary iodine and thyroid hormones, respectively. Median UIE of Dhankuta and Sunsari were 238.00 μg/L and 294.96 μg/L respectively. Relatively higher percentage (31.8%) of subclinical hypothyroid cases was found in Sunsari than Dhankuta (29.59%).

Urinary Iodine Excretion of Lactating Mothers Predicts the Iodine Content of Their Breast Milk.

Background: Iodine is essential for normal growth, mental development and survival of infants. Bangladesh is an iodine deficient region. Breast milk is the only source of iodine for exclusively breast-fed infants. Routine measurement of breast milk iodine concentration is very difficult in our country due to some social and religious barriers. So, we designed this study in our population using urinary iodine as the indicator for assessing iodine status. Objectives: To assess the iodine status of lactating mothers and their breast-fed infants and to propose a method on how to predict the iodine concentration in breast milk. Materials and Methods: This observational analytical study was carried out in the department of Biochemistry, Bangabandhu Sheikh Mujib Medical University, Dhaka with active cooperation of Kumudini Women’s Medical College Hospital, Mirzapur, Tangail involving fifty lactating mothers and their exclusively breast-fed infants. Early morning urine and breast milk samples were collected in dry and clean plastic container free from any chemical contamination. All statistical analyses were done by using SPSS (Statistical Programme for Social Science) 12 version software package for windows. Results: The median (range) urinary iodine concentration of lactating mothers and their breast-fed infants were 225.25 μg/L (61.50-530.00) and 225.75 μg/L (100.50-526.50). 96% (48) mothers had no biochemical iodine deficiency (UIE ≥100μg/L), only 4% (2) mothers had mild biochemical iodine deficiency (UIE 50-99μg/L). There was no biochemical deficiency of breast-fed infants. The median (range) breast-milk iodine concentration was 157 μg/L (54.50-431.50) which was more than three times of recommended minimum concentration (50 μg/L). Iodine in breast milk of lactating mothers positively correlated with their urinary iodine excretion (P<0.01). Infant’s urinary iodine positively correlated with iodine concentration in breast milk (P<0.01) and also positively correlated with urinary iodine excretion of lactating mothers. Conclusion: Lactating mothers and their breast-fed infants in this study were found iodine sufficient. Urinary iodine concentration of lactating mothers predicts the iodine content of their breast milk.

Iodine deficiency disorders after a decade of universal salt iodization in a severe iodine deficiency region in China.

Background & objectives: Universal salt iodization (USI) was implemented in all counties of China in 1995. This study was undertaken to assess the status of iodine deficiency disorders control and prevention after 10 years of implementation of USI in a severe iodine deficiency region in China. Methods: Thirty primary school were selected in Gansu province utilizing cluster sampling methodology for the years 1995 and 2005. In each selected school, 40 children aged 8-10 yr were randomly selected for thyroid and IQ examination, and urinary samples were collected from 12. On the spot casual urine samples and salt samples were collected from a subset of children included in the study. In 2005, casual urine samples were also collected from 50 pregnant and lactating women in each cluster. Effect of health education was studied by a combination method of giving questionnaires to and observing students and families. Results: The total goiter rates (TGR) were found to be 13.5 and 38.7 per cent in 2005 and 1995 respectively. The medians urinary iodine excretion levels of children were 191.8 and 119.9 μg/l in 2005 and 1995. The median urinary iodine excretion level of women was 161.9 μg/l. The mean intelligence quotient (IQ) was 96.9 in 2005 significantly more than that in 1997 (P<0.05). The health education pass rate of children and women were 21.1 and 51.1 per cent respectively. Interpretation & conclusion: After ten years of universal salt iodization (USI), iodine nutrition of people improved and the current iodine nutrition status of population was adequate. Decrease in TGR and increase in IQ showed that IDD control and prevention had made great progress through ten years USI, salt iodization played the key role in IDD control and prevention for sustained elimination of IDD, the programme of USI and other measures like health education should be persisted and enforced.