Iodine deficiency during infancy and early childhood in Belgium: does it pose a risk to brain development?

Iodine deficiency is well documented in Belgium in adults including pregnant women, adolescents, schoolchildren, and neonates, but no data are available in the age group 6 months–3 years. We investigated the status of iodine nutrition in 111 healthy subjects in this age group in an attempt to evaluate the risk of brain damage due to iodine deficiency in Belgium. In 244 casual urine samples collected in these subjects, the median concentration of iodine was 101 μg/l vs 180–220 μg/l under normal conditions. The daily supplementation of the subjects with a physiological dose of 90 μg iodine was followed by a slow and progressive increase of urinary iodine, which reached a normal level only after a delay of about 30 weeks of therapy. This observation suggests that part of the supplement of iodine offered to the children was stored in their thyroid glands until the iodine content of the gland had reverted to normal, reflecting the state of hyperavidity of the thyroid for iodide characteristic of iodine deficiency. In conclusion, infants and young children in Belgium are as iodine deficient as all other age groups of the population and, consequently, are at risk of brain damage. This works further illustrates the need for systematic iodine supplementation of the population in Belgium. Received: 19 September 2000 / Accepted: 11 October 2000     

Iodine status of breastfed infants and their mothers' breast milk iodine concentration

Iodine is an essential nutrient for growth and development during infancy. Data on iodine status of exclusively (EBF) and partially breastfed (PBF) infants as well as breast milk iodine concentration (BMIC) are scarce. We aimed to assess (a) infant iodine nutrition at the age of 5.5 months by measuring urinary iodine concentration (UIC) in EBF (n = 32) and PBF (n = 28) infants and (b) mothers' breast milk iodine concentration (n = 57). Sixty mother–infant pairs from three primary health care centres in Reykjavik and vicinities provided urine and breast milk samples for iodine analysis and information on mothers' habitual diet. The mother–infant pairs were participants of the IceAge2 study, which focuses on factors contributing to infant growth and development, including body composition and breast‐milk energy content. The median (25th–75th percentiles) UIC was 152 (79–239) μg/L, with no significant difference between EBF and PBF infants. The estimated median iodine intake ranged from 52 to 86 μg/day, based on urinary data (assuming an average urine volume of 300–500 ml/day and UIC from the present study). The median (25th–75th percentiles) BMIC was 84 (48–114) μg/L. It is difficult to conclude whether iodine status is adequate in the present study, as no ranges for median UIC reflecting optimal iodine nutrition exist for infants. However, the results add important information to the relatively sparse literature on UIC, BMIC, and iodine intake of breastfed infants.     

Jaundice in full term healthy neonates — a population study

Abstract A geographically based population of 498 full term, appropriate for gestational age, healthy, singleton neonates was used to study the effect of obstetric and nursery practices on the occurrence of neonatal jaundice. At 3–4 days 56% of babies became visibly jaundiced (plasma bilrubin (PB)> 100 μmol/l) and 10% were hyperbilirubinaemic (PB > 200 μmol/I). Less mature babies, those slow to pass meconium and those who had lost weight at 4 and 7 days were more likely to be jaundiced. Obstetric practices, drugs given during labour, mother's or baby's blood group, natural illumination, plethora, extravasated blood or mode of feeding were found to have no effect. No benefit from giving supplementary milk or dextrose to breast fed babies was discovered.
At 6–7 days at least 9% of babies, all bout one of whom were breast fed, were visibly jaundiced. The frequency of prolonged jaundice (breast milk jaundice) was 3'.8% of breast fed babies at 3 weeks and zero by 7 weeks. The proportion of babies receiving phototherapy was 2.2%.     

Vitamin B6 Intake and Plasma Pyridoxal Phosphate Concentrations in the First 2 Weeks of Life

ABSTRACT. Plasma pyridoxal phosphate concentrations were measured in 178 hospitalised neonates. A reference interval for neonates less than 7 day old, of 25 to 78 nmol/l has been established. Vitamin B₆ intakes did not correlate well with plasma pyridoxal concentrations despite 26 neonates receiving less than the Recommended Allowance (0.3 mg/d) and 19 receiving amounts below which convulsions have been associated (0.1 mg/d). Ten percent of those infants fed breast milk had plasma pyridoxal phosphate levels below the reference interval compared with only 4 % of those fed milk formulae. Breast milk from mothers with babies less than 14 days old had a total vitamin B₆ contents reference interval of 5 to 40 μg/l. Twenty percent of breast milk samples had virtually no vitamin B₆ detected.     

Selenium status of New Zealand infants fed either a selenium supplemented or a standard formula

Objective: New Zealand soils are deficient in the essential micronutrient, selenium. New Zealand infants have low selenium levels at birth and experience a further decline if fed cows milk based formula. This study examined the selenium status of infants fed with a new commercially available selenium supplemented formula.
Methodology Forty-four newborn infants, whose mothers wished to formula feed, were randomized in an open controlled trial to be fed a commercially available selenium supplemented cows milk formula (containing 17 μg Se/L) or an unsupplemented formula (containing 4.6 μg Se/L). Cord, 1 and 3 month blood samples were obtained for selenium status (plasma and red cell selenium and glutathione peroxidase) and thyroid function.
Results Mean plasma selenium and glutathione peroxidase values were significantly higher in supplemented than unsupplemented infants at 1 month (unpaired t -tests; P <0.0001 and P = 0.001 respectively) and 3 months ( P <0.0001 and P = 0.0005). Analysis within treatment groups between time points (paired t -tests) showed that selenium supplementation prevented the fall in plasma selenium from birth to 1 month seen in unsupplemented infants and was associated with a rise in levels between 1 and 3 months ( P = 0.002).
Conclusions Supplementing cows milk formula with selenium to replicate the levels found in breast milk is nutritionally sound. Feeding from a few days of age with a formula containing 17 μg Se/L in infants with low selenium status at birth is sufficient to cause a rise to 80% of adult levels at 3 months of age.     

Incidence of iodine deficiency in Turkish patients with congenital hypothyroidism

Background: Turkey is located in an area of mild to moderate iodine deficiency. The aim of the present study was to investigate the incidence of iodine deficiency in patients with congenital hypothyroidism.
Methods: Twenty five patients with a median age of 12 days (6 days–6 months) at diagnosis and followed for a median time of 7 months (1–60 months) were enrolled in the study. Thyroid function tests, thyroid scintigraphy, ultrasonography and urine iodine measurements of the patients and mothers were performed.
Results and conclusion: Congenital hypothyroidism was diagnosed within postnatal day 13, between days 13 and 30, and after 30 days of age in 68%, 20% and 12% of the patients, respectively. At the time of diagnosis mean serum thyroid-stimulating hormone and total T4 were 85.3 ± 27.6 mIU/L and 3.9 ± 2.8 μg/dL, respectively. Incidence of iodine deficiency was 36% in the patients (median, 110 μg/L) and 88% in the mothers (median, 40 μg/L). Thyroid scintigraphy and ultrasound were normal in all of the patients with iodine deficiency. At scintigraphic evaluation, thyroid gland was not visualized in 28% of patients; in the patients whose thyroid glands were not visualized scintigraphically thyroid ultrasonography indicated agenesis in 57%, and hypoplasia in 43%. In all the patients with thyroid agenesis or hypoplasia iodine levels were normal. In 36% of the patients imaging studies of thyroid gland and urine iodine measurements were normal. Despite salt iodization program, incidence of iodine deficiency is still high in patients with congenital hypothyroidism and mothers. National measures are urgently required for correction of iodine deficiency in Turkey.     

Effect of Phosphate Supplementation to Breast Fed Very Low Birthweight Infants on Urinary Calcium Excretion, Serum Immunoreactive Parathyroid Hormon and Plasma 1.25-Dihydroxy-vitamin D Concentration

ABSTRACT. The effect of two doses of Phosphorus (P) supplementation to pooled breast milk (BM): 0.48 and 0.800 mmol/kg/24 h given during the second month of life was evaluated in 22 very low birthweight infants. The concentration of calcium and phosphorus in serum and urine, the serum concentration of immunoreactive parathyroid hormon (iPTH) and the plasma 1,25-dihydroxy-vitamin D concentration (1,25-OH-D) were compared to the values in 19 control infants. The mean ± SD concentrations in control infants and adults are 63 ±18 ulEq/ml for serum iPTH and 85±pmol/l for plasma 1,25-OH-D. With 0.48 P supplementation, urinary Ca (UCa) excretion (median and range) 0.238 mmol/kg/24 h (0.105-0.520) was lower than in the control group 0.288 (0.205-0.679) (p<0.05); the reduction of UCa was larger with 0.8 P supplementation: 0.047 (0.023-0.163) (p<0.01). P supplementation induced no change in serum Ca concentration but a slight and significant increase in serum iPTH was observed only with the 0.8 P supplementation: 55 μl Eq/ml (<25-80) (p<0.05). With 0.8 P supplementation there was no significant change of plasma 1,25-OH-D concentration: 173 μmol/l (106-271) vs. 255 (132-293) in the control group. These data show that with 0.8 P supplementation, the hypercalciuria in BM-fed infant disappears without secondary hyperparathyroidism, but without any change in plasma 1,25-OH-D concentration.     

Iodine status in pregnancy and household salt iodine content in rural Bangladesh

Adequate maternal iodine intake is essential during pregnancy for the development of the foetus. To assess the extent of iodine insufficiency and its association with household iodized salt in rural Bangladesh, we measured urinary iodine and household salt iodine content among pregnant women in early (≤16 weeks, n = 1376) and late (≥32 weeks, n = 1114) pregnancy. Salt (～20 g) and a spot urine sample (～10 mL) were collected from women participating in a randomized, placebo‐controlled trial of vitamin A or beta‐carotene supplementation in rural northwestern Bangladesh during home visits in early and late pregnancy. Salt iodine was analyzed by iodometric titration, and urinary iodine by the Ohashi method. Almost all salt samples had some detectable iodine, but over 75% contained <15 ppm. Median (interquartile range) urinary iodine concentrations were 66 (34–133) and 55 (28–110) µg L^?1 in early and late pregnancy, respectively; urinary iodine <150 µg L^?1 was found in ～80% of women at both times in pregnancy. Although the risk of iodine insufficiency declined with increasing iodine content of household salt (P for trend <0.05), median urinary iodine did not reach 150 µg L^?1 until iodine in household salt was at least 32 ppm and 51 ppm during early and late pregnancy, respectively. Despite a national policy on universal salt iodization, salt iodine content remains insufficient to maintain adequate maternal iodine status throughout pregnancy in rural northern Bangladesh. Alternative measures like direct iodine supplementation during pregnancy could be considered to assure adequate iodine status during this high‐risk period of life.     

云南省695例母亲和新生儿尿碘及新生儿血促甲状腺激素水平的调查分析

目的了解母亲尿碘与新生儿尿碘及血促甲状腺激素(TSH)水平及相关性。方法选取695例母亲及其新生儿作为研究对象,采集母亲和新生儿尿液检测尿碘,采集新生儿足跟血检测TSH。结果 695例母亲的尿碘中位数为212.9μg/L,239例(34.39%)母亲尿碘149μg/L为碘缺乏,143例(20.58%)母亲尿碘在150~249μg/L间为碘适量,163例(23.45%)母亲尿碘在250~499μg/L间为碘超足量,150例(21.58%)母亲尿碘≥500μg/L为碘过量;新生儿尿碘中位数为345.7μg/L;母亲尿碘水平与其新生儿尿碘呈正相关(r_s=0.576,P?0.001);新生儿TSH为(3.24±1.75)m IU/L,其中88例(12.66%)TSH5 m IU/L;母亲碘缺乏及碘过量的新生儿的TSH水平及TSH5 m IU/L的比例均高于母亲碘适量或碘超足量的新生儿,差异有统计学意义(P0.05)。结论本调查中母亲总体处于碘适量水平,但仍有较高比例的碘缺乏或碘过量;母亲尿碘水平与新生儿尿碘水平密切相关;碘缺乏或碘过量母亲生育高TSH新生儿的风险较高。     

The effect of formula versus breast feeding and exogenous vitamin K1 supplementation on circulating levels of vitamin K1 and vitamin K-dependent clotting factors in newborns

The influence of breast or formula feeding together with that of a single supplementation of vitamin K₁ at birth, on the vitamin K₁ level and vitamin K-dependent clotting factors were studied in 65 breast and 15 formula fed infants. All breast fed newborns without supplementation (n=25) had very low serum vitamin K₁ at weeks 1 and 6. Oral vitamin K supplementation (n=22) or i.m. (n=18) at birth resulted in high serum levels at week 1, while at week 6 the effect had disappeared. Formula fed infants had vitamin K₁ values within the normal adult range at all study points. The low serum levels of vitamin K₁ were not associated with haemorrhagic disorders or coagulation abnormalities. The mean values of vitamin K₁ in maternal sera at weeks 1 and 6 were 2.3 nmol/l and 1.8 nmol/l and in breast milk 2.7 nmol/l and 2.0 nmol/l respectively. No correlation existed between the values in breast milk and maternal serum. To maintain serum levels of vitamin K₁ within the adult physiological range, repeated administration of low doses is needed in breast fed newborns beyond 1 week of age.     

转乳期婴儿不同喂养方式对其碘营养变化的影响

目的了解母乳喂养婴儿及其乳母碘营养水平;动态观察从1个月月龄至6个月月龄转乳期时不同喂养方式对婴儿碘营养的影响.方法对97名1个月月龄母乳喂养婴儿尿碘水平进行测定,同时检测其乳母乳碘、尿碘水平,比较二者关系;动态观察97名婴儿从出生至6个月月龄,按喂养方式分为母乳、混合、人工喂养三组,分别检测比较其尿碘水平,与1个月月龄时尿碘水平进行自身对照比较.结果 1个月月龄母乳喂养婴儿尿碘中位数为183 μg/L,提示碘营养状态良好,乳母尿碘、乳碘中位数分别为122 μg/L、201 μg/L,前者明显低于后者(P＜0.001);6个月月龄尿碘水平与1个月月龄比较,母乳喂养组较前升高,人工喂养组下降(P均<0.001),混合喂养组无明显变化(P＞0.05),3组间差异有显著意义(P＜0.005),母乳及混合喂养组明显高于人工喂养(P均<0.001),母乳喂养组婴儿尿碘中位数最高.结论母乳喂养儿碘营养状态良好,乳母碘营养不足;转乳期婴儿碘营养呈下降趋势,部分人工喂养婴儿存在碘营养不良.     

Iodine and hypothyroidism in neonates with congenital heart disease

AIM—To evaluate the influence of the intravenous injection of iodine during cardiac catheterisation, and of topical iodine antiseptics during surgical procedures, on thyroid function in full term neonates.
METHODS—Twenty one full term infants with major cardiac anomalies who survived for more than a month were studied. Thyroxine and thyrotropin concentrations were measured (by radioimmunoassay) before each procedure, 24 hours after the procedure, and every week thereafter until the age of 1 month or until normal. Thyroxine values less than 64.4 nmol/l were considered low, while thyrotropin values greater than 30 mU/l were considered high.
RESULTS—Thyroid function tests before iodine exposure were within normal limits in all infants. Following catheterisation or surgery six infants had raised thyrotropin concentrations; three had low thyroxine concentrations. Two of those infants were treated with L-thyroxine.
CONCLUSION—Iodine exposure during cardiac catheterisation or surgery may induce transient hypothyroidism in term infants.

     

The nutritional iodine supply of Belgian neonates is still insufficient

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 micro g/l, which is markedly higher than the figure of 48 micro g/L reported 15 years previously in neonates in the same area but still much lower than normal for this age group (150-200 micro g/l). The mean iodine content of breast-milk was 78 micro g/l, which is unchanged as compared to 15 years ago and is about 66% of normal. Finally, the median urinary iodine increased from 60 micro g/l on day 5 to 150 micro g/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.     

The selenium status of children with phenylketonuria: Results of selenium supplementation

The selenium status of children with phenylketonuria on a synthetic low phenylalanine diet was assessed. Correlation between blood selenium and red cell glutathione peroxidase was unsatisfactory ( r = 0.65) due to the poor discrimination of red cell glutathione peroxidase with a low selenium diet. No symptoms of deficiency were observed. Supplementation with 50 μg per week of selenium as brewers yeast tablets over a period of 6 months significantly increased the blood selenium of the phenylketonuric children. Plasma Vitamin E levels were within normal limits. The supplementation effectively doubled their selenium intake to 15–17 μg per day, which is probably sufficient for this group with an adequate Vitamin E status, though considerably lower than the recommended minimum intake of 50 μg per day.     

Iodine status and goiter prevalence after 40 years of salt iodisation in the Kangra district, India

Thirty primary schools were selected in district Kangra utilizing the population proportionate to size cluster sampling methodology in the year 2004. A total of 6939 children were included in the study. The clinical examination of the thyroid of each child was conducted. On the spot casual urine sample and salt samples were collected from a ‘sub set of’ children included in the study. The Total goiter rate (TGR) was found to be 19.8%. The median Urinary iodine excretion level was 200 μg/l and only 64% of the salt samples had the stipulated level of iodine. The findings of the present study revealed that current iodine status of population is adequate, however, TGR showed mild iodine deficiency (chronic), and there is a need of continued monitoring the quality of iodised salt provided to the beneficiaries under the Universal salt iodisation programme in order to achieve the goal of elimination of lodine deficiency disorders from district Kangra.     

Metabolic Acidosis and Renal Solute Load in Relation to the Protein Intake of Low Birth Weight Malaysian Neonates

Johnson, R. O., Johnson, B. H., Raman, A., Lee, E. L., and Lam, K. L. (1979) Aust. Paediatr. J. , 15, 101–106. Metabolic acidosis and renal solute load in relation to the protein intake of low birth weight Malaysian neonates. Thirty-one low birth weight Malaysian neonates were divided into two groups for the purpose of comparing two different dilutions of modified cow's milk. One dilution supplied 2.4 g protein/100 kcal (16.9 g/l) and the other 3.3 g/100 kcal (22.5 g/l). The two milks were iso-caloric at 69 kcal/100 ml. Clinical observation and weekly estimations of acid-base status, plasma sodium, chloride, potassium, urea and osmolality and of urine osmolality were made during the first three weeks of life. Metabolic acidosis was observed in both groups of infants, being significantly more severe in the higher protein group. Most acidotic babies remained asymptomatic. Plasma urea and plasma and urine osmolalities were all significantly higher in the higher protein group. No case of hyperosmolality occurred. Caution is recommended when feeding cow's milk of protein density greater than 2.4 g/100 kcal to low birth weight infants.     

Iodine status and associations with feeding practices and psychomotor milestone development in six‐month‐old South African infants

Iodine is important for normal growth and psychomotor development. While infants below 6 months of age receive iodine from breast milk or fortified infant formula, the introduction of complementary foods poses a serious risk for deteriorating iodine status. This cross‐sectional analysis assessed the iodine status of six‐month‐old South African infants and explored its associations with feeding practices and psychomotor milestone development. Iodine concentrations were measured in infant (n = 386) and maternal (n = 371) urine (urinary iodine concentration [UIC]), and in breast milk (n = 257 [breast milk iodine concentrations]). Feeding practices and psychomotor milestone development were assessed in all infants. The median (25th–75th percentile) UIC in infants was 345 (213–596) μg/L and was significantly lower in stunted (302 [195–504] μg/L) than non‐stunted (366 [225–641] μg/L) infants. Only 6.7% of infants were deficient. Maternal UIC (128 [81–216] μg/L; r_s = 0.218, p < 0.001) and breast milk iodine concentrations (170 [110–270] μg/kg; r_s = 0.447, p < 0.0001) were associated with infant UIC. Most infants (72%) were breastfed and tended to have higher UIC than non‐breastfed infants (p = 0.074). Almost all infants (95%) consumed semi‐solid or solid foods, with commercial infant cereals (60%) and jarred infant foods (20%) being the most common solid foods first introduced. Infants who reported to consume commercial infant cereals ≥4 days weekly had significantly higher UIC (372 [225–637] μg/L) than those reported to consume commercial infant cereals seldom or never (308 [200–517] μg/L; p = 0.023). No associations between infant UIC and psychomotor developmental scores were observed. Our results suggest that iodine intake in the studied six‐month‐old infants was adequate. Iodine in breast milk and commercial infant cereals potentially contributed to this adequate intake.     

Iodine nutritional status and risk factors for iodine deficiency in infants and children of the french North department]

INTRODUCTION: Iodine deficiency is responsible for a higher mortality and morbidity in neonates and infants. It has not yet disappeared in European countries, especially in Southern and Eastern Europe. OBJECTIVES: The present study aimed at evaluating the status of iodine nutrition of infants living in the North department (France) and at studying risk factors for iodine deficiency. METHODS: The study was conducted in primary health care centres in 160 healthy infants aged ten days to six years (mean +/- SD: 17.7 +/- 2.5 months). Data included: familial thyroid disease history, type of feeding at inclusion, timing of introduction of complementary foods, nutritional status (weight, height, head and arm circumference), as well as maternal education level and family socio-economical status. Iodine status was assessed by urinary iodine excretion. RESULTS: Urinary iodine concentration ranged from 4 to 1042 microg/l (median +/- SD: 195,5 +/- 21,6 microg/l). Thirty-eight (24%) of 160 children were iodine deficient (urinary iodine < 100 microg/l): mild iodine deficiency (50-99 microg/l: 17%), moderate iodine deficiency (20-49 microg/l: 5%), severe iodine deficiency (<20 microg/l: 2%). No relationship was found between iodine status and age, sex, geographic origin of the children, as well as social and occupational group of the parents. Breast-feeding did not prevent from iodine deficiency. Iodine status did not differ between the cow's milk fed group and the group that was not fed cow's milk. Formula feeding was associated with iodine deficiency (p = 0,02). CONCLUSIONS: Prevalence of severe iodine deficiency was very low in this population. However, iodine status was not optimal.     

Aluminium in the neonate related to parenteral nutrition

Moreno A, Domínguez C, Ballabriga A. Aluminium in the neonate related to parenteral nutrition. Acta Pædiatr 1994;83:25–9. Stockholm. ISSN 0803–5253
Sources of aluminium loading and exposure in preterm and full-term newborns were studied. Parenteral nutrition solutions were the main source of aluminium representing 88.7% of total aluminium intake. Blood and urine aluminium levels were followed over a 28-day period in a group of 26 preterm and 9 term infants while receiving parenteral nutrition (duration 15.6 ± 8.7 days) and later when being formula fed. Urine levels were followed up to 13 weeks in a subgroup of the neonates. Serum aluminium levels (0.86 ± 0.38 μmol/l) and urine aluminium/crcatinine ratio (1.52 ± 0.81 μ mol/ mmol) were increased when the infants were receiving parenteral nutrition compared with the control group (p<0.001). The urine aluminium/creatinine ratio remained high up to 10 weeks following withdrawal of parenteral nutrition and suggested tissular loading. This was confirmed after high aluminium levels were found in post-mortem brain and bone samples from two preterm and one full-term infant. We conclude that both preterm and full-term neonates are susceptible to accumulation of aluminium in tissue while receiving parenteral nutrition.     

Iodine intake and status during pregnancy and lactation before and after government initiatives to improve iodine status,in Palmerston North,New Zealand: a pilot study

Iodine deficiency during pregnancy and lactation may adversely affect fetal and infant development. Two initiatives were introduced in New Zealand to prevent deficiency: (1) mandatory fortification of bread with iodised salt; and (2) provision of a subsidised iodine supplement (150 μg) for all pregnant and breastfeeding women. The aim of this study was to assess iodine intake and status among a self‐selecting sample of pregnant and lactating women in Palmerston North, both before and after the two initiatives. Pregnant and breastfeeding women were recruited before (n = 25 and 32; 2009) and after (n = 34 and 36; 2011) the initiatives. Iodine concentration was determined in 24‐h urine and breast milk samples using inductively‐coupled plasma mass spectrometry. Use of supplements and salt, knowledge of iodine deficiency, and awareness of the initiatives were determined by questionnaire. Median urine iodine concentration (UIC) was higher in 2011 compared with 2009 for both pregnant (85 and 47 μg L^?1) and breastfeeding (74 and 34 μg L^?1) participants; median UIC were below the cut‐offs for adequate iodine status. However, in 2011, the estimated daily iodine intake during pregnancy was 217 μg day^?1; 74% of women achieved the Estimated Average Requirement. Knowledge of the initiatives was low, only 28–56% were aware of the need for iodine supplements and only 15–22% were aware of the mandatory addition of iodised salt to bread. Despite initiatives, UIC of these women indicates iodine deficiency, however, dietary intakes appear adequate. Ongoing surveillance of supplement use and iodine status among pregnant and lactating women throughout New Zealand is needed to fully assess the efficacy of the initiatives. Alternative strategies may require evaluation to ensure all women have adequate iodine during pregnancy and breastfeeding.