Endocrine Abstracts

Iodine status surveys in pregnant cohorts in the UK and Ireland have demonstrated deficiency since 1990s, but there is no nationwide fortification program unlike many other European countries. Therefore, dietary modification and supplementation are key. Milk/dairy products are the main dietary sources of iodine locally. One previous RCT of milk provision in non-pregnant women in NI reported improved iodine status after 3L/week milk. We recruited 118 women at booking. Each received the British Dietetic Association iodine fact sheet. Those randomised to intervention also received 4L/week milk (or yoghurt) for 12-weeks. Cohort median urinary iodine concentration (mUIC) for sufficiency in pregnancy is >150 µg/l. Mean maternal age was 32 years (range 21 – 45 years), gestational age 12.1 weeks, BMI 27.5 kg/m2 and deprivation scores were in moderate range. Use of an iodine-containing supplement was reported in 71.4%. The intervention group mUIC was 53.8 µg/l at baseline and 120.7 µg/l after 12-weeks while the control group had mUIC 52.5 µg/l and 105.7 µg/l respectively (mean change 81.8 vs 44.5 µg/l, P = 0.27). Urine samples from 55 infants had mUIC 125 µg/l (sufficiency >100 µg/l) with no difference between groups. Food Frequency Questionnaires showed a trend towards increased milk consumption (P = 0.06) in the intervention group. In the intervention group, 10.2% were sufficient at baseline rising to 37.2% after 12-weeks (27% improvement) vs control group 22.0% to 32.4% respectively (10% improvement) (P = 0.08 and P = 0.66 between groups). The study was underpowered to detect this magnitude of difference. This is the fourth consecutive pregnant cohort on the island of Ireland to demonstrate iodine deficiency since 1997 despite high levels of supplementation. We believe this is the first milk provision RCT in pregnancy and, in the absence of any prospects of a fortification program, further dietary trials are worthwhile.