The nutritional iodine supply of Belgian neonates is still insufficient

Abstract.

Belgium used to be affected by mild iodine deficiency. Improvement in iodine nutrition has been recently documented in schoolchildren in Belgium in spite of the absence of any systematic programme of iodine supplementation. The question arises as to whether this 'silent iodine prophylaxis' affected also the neonates. A total of 185 random urine samples were collected from 90 full term and 65 preterm neonates in Brussels on day 5 and repeated on day 30 in 30 preterms who were bottle-fed with iodine-enriched formula-milk. The iodine content was also determined in 58 samples of breast-milk on day 5. The median urinary iodine on day 5 in full term neonates was 86 µg/l, which is markedly higher than the figure of 48 µg/L reported 15 years previously in neonates in the same area but still much lower than normal for this age group (150–200 µg/l). The mean iodine content of breast-milk was 78 µg/l, which is unchanged as compared to 15 years ago and is about 66% of normal. Finally, the median urinary iodine increased from 60 µg/l on day 5 to 150 µg/l on day 30 in preterms bottle-fed with iodine-enriched formula-milk. Conclusion: the status of iodine nutrition has also improved spontaneously in Belgian neonates but has not yet normalised. Lactating and probably pregnant women remain clearly iodine deficient. The iodine-enriched formula-milk for preterms is efficient in correcting their iodine deficiency. National measures are urgently required for correction of iodine deficiency in Belgium.