1
|
Abstract
Iodine is a micronutrient needed for the production of thyroid hormones, which regulate metabolism, growth, and development. Iodine deficiency or excess may alter the thyroid hormone synthesis. The potential effects on infant development depend on the degree, timing, and duration of exposure. The iodine requirement is particularly high during infancy because of elevated thyroid hormone turnover. Breastfed infants rely on iodine provided by human milk, but the iodine concentration in breast milk is determined by the maternal iodine intake. Diets in many countries cannot provide sufficient iodine, and deficiency is prevented by iodine fortification of salt. However, the coverage of iodized salt varies between countries. Epidemiological data suggest large differences in the iodine intake in lactating women, infants, and toddlers worldwide, ranging from deficient to excessive intake. In this review, we provide an overview of the current knowledge and recent advances in the understanding of iodine nutrition and its association with thyroid function in lactating women, infants, and toddlers. We discuss risk factors for iodine malnutrition and the impact of targeted intervention strategies on these vulnerable population groups. We highlight the importance of appropriate definitions of optimal iodine nutrition and the need for more data assessing the risk of mild iodine deficiency for thyroid disorders during the first 2 years in life.
Collapse
Affiliation(s)
- Maria Andersson
- Nutrition Research Unit, University Children’s Hospital Zurich, CH-8032 Zürich, Switzerland
| | - Christian P Braegger
- Nutrition Research Unit, University Children’s Hospital Zurich, CH-8032 Zürich, Switzerland
| |
Collapse
|
2
|
Schiera G, Di Liegro CM, Di Liegro I. Involvement of Thyroid Hormones in Brain Development and Cancer. Cancers (Basel) 2021; 13:2693. [PMID: 34070729 PMCID: PMC8197921 DOI: 10.3390/cancers13112693] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 12/21/2022] Open
Abstract
The development and maturation of the mammalian brain are regulated by thyroid hormones (THs). Both hypothyroidism and hyperthyroidism cause serious anomalies in the organization and function of the nervous system. Most importantly, brain development is sensitive to TH supply well before the onset of the fetal thyroid function, and thus depends on the trans-placental transfer of maternal THs during pregnancy. Although the mechanism of action of THs mainly involves direct regulation of gene expression (genomic effects), mediated by nuclear receptors (THRs), it is now clear that THs can elicit cell responses also by binding to plasma membrane sites (non-genomic effects). Genomic and non-genomic effects of THs cooperate in modeling chromatin organization and function, thus controlling proliferation, maturation, and metabolism of the nervous system. However, the complex interplay of THs with their targets has also been suggested to impact cancer proliferation as well as metastatic processes. Herein, after discussing the general mechanisms of action of THs and their physiological effects on the nervous system, we will summarize a collection of data showing that thyroid hormone levels might influence cancer proliferation and invasion.
Collapse
Affiliation(s)
- Gabriella Schiera
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche) (STEBICEF), University of Palermo, 90128 Palermo, Italy; (G.S.); (C.M.D.L.)
| | - Carlo Maria Di Liegro
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche) (STEBICEF), University of Palermo, 90128 Palermo, Italy; (G.S.); (C.M.D.L.)
| | - Italia Di Liegro
- Department of Biomedicine, Neurosciences and Advanced Diagnostics (Dipartimento di Biomedicina, Neuroscienze e Diagnostica avanzata) (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| |
Collapse
|
3
|
Groufh-Jacobsen S, Mosand LM, Oma I, Sletten Bakken K, Stokke Solvik B, Lovise Folven Gjengedal E, Brantsæter AL, Strand TA, Henjum S. Mild to Moderate Iodine Deficiency and Inadequate Iodine Intake in Lactating Women in the Inland Area of Norway. Nutrients 2020; 12:E630. [PMID: 32120975 PMCID: PMC7146631 DOI: 10.3390/nu12030630] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/19/2020] [Accepted: 02/25/2020] [Indexed: 12/14/2022] Open
Abstract
Breastfed infants are dependent on an adequate supply of iodine in human milk for the production of thyroid hormones, necessary for development of the brain. Despite the importance of iodine for infant health, data on Norwegian lactating women are scarce. We measured iodine intake and evaluated iodine status and iodine knowledge among lactating women. From October to December 2018, 133 mother-infant pairs were recruited in a cross-sectional study through two public health care centers in Lillehammer and Gjøvik. Each of the women provided two human milk specimens, which were pooled, and one urine sample for analysis of iodine concentration. We used 24-hour dietary recall and food frequency questionnaire (FFQ) to estimate short-term and habitual iodine intake from food and supplements. The median (P25, P75) human milk iodine concentration (HMIC) was 71 (45, 127) µg/L-of which, 66% had HMIC <100 µg/L. The median (P25, P75) urinary iodine concentration (UIC) was 80 µg/L (52, 141). The mean (± SD) 24-hour iodine intake and habitual intake was 78 ± 79 µg/day and 75 ± 73 µg/day, respectively. In conclusion, this study confirms inadequate iodine intake and insufficient iodine status among lactating women in the inland area of Norway and medium knowledge awareness about iodine.
Collapse
Affiliation(s)
- Synne Groufh-Jacobsen
- Department of Research, Innlandet Hospital Trust, 2629 Lillehammer, Norway;
- Department of Nursing and Health Promotion, Faculty of Health Sciences, OsloMet–Oslo Metropolitan University, 0130 Oslo, Norway;
| | - Lise Mette Mosand
- Department of Clinical Medicine, University of Oslo, 0450 Oslo, Norway;
- Department of Medical Microbiology, Innlandet Hospital Trust, 2629 Lillehammer, Norway;
| | - Ingvild Oma
- Department of Medical Microbiology, Innlandet Hospital Trust, 2629 Lillehammer, Norway;
| | - Kjersti Sletten Bakken
- Women’s Clinic at Lillehammer Hospital, Innlandet Hospital Trust, 2629 Lillehammer, Norway; (K.S.B.); (B.S.S.)
| | - Beate Stokke Solvik
- Women’s Clinic at Lillehammer Hospital, Innlandet Hospital Trust, 2629 Lillehammer, Norway; (K.S.B.); (B.S.S.)
| | - Elin Lovise Folven Gjengedal
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, 1432 Aas, Norway;
| | - Anne Lise Brantsæter
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, 0213 Oslo, Norway;
| | - Tor Arne Strand
- Department of Research, Innlandet Hospital Trust, 2629 Lillehammer, Norway;
| | - Sigrun Henjum
- Department of Nursing and Health Promotion, Faculty of Health Sciences, OsloMet–Oslo Metropolitan University, 0130 Oslo, Norway;
| |
Collapse
|
4
|
Vandenplas Y, Rakhecha A, Edris A, Shaaban B, Tawfik E, Bashiri FA, AlAql F, Alsabea H, Haddad J, El Barbary M, Salah M, Abouelyazid M, Kumar M, Alsaad S. Physicians' Understanding of Nutritional Factors Determining Brain Development and Cognition in the Middle East and Africa. Pediatr Gastroenterol Hepatol Nutr 2019; 22:536-544. [PMID: 31777719 PMCID: PMC6856510 DOI: 10.5223/pghn.2019.22.6.536] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 07/20/2019] [Indexed: 01/24/2023] Open
Abstract
PURPOSE Proper nutrition is essential for brain development during infancy, contributing to the continued development of cognitive, motor, and socio-emotional skills throughout life. Considering the insufficient published data in the Middle East and North Africa, experts drafted a questionnaire to assess the opinions and knowledge of physicians on the impact of nutrition on brain development and cognition in early life. METHODS The questionnaire consisted of two parts: The first focused on the responders' demographic and professional characteristics and the second questioned the role of nutrition in brain development and cognition. Descriptive statistics were used to summarize respondents' characteristics and their responses to questions. RESULTS A total of 1,500 questionnaires were distributed; 994 physicians responded. The majority of the surveyed physicians (64.4%) felt that nutrition impacts brain development in early childhood (0-4 years), with almost 90% of physicians agreeing/strongly agreeing that preventing iron, zinc, and iodine deficiency would improve global intelligence quotient. The majority of physicians (83%) agreed that head circumference was the most important measure of brain development. The majority of physicians (68.9%) responded that the period from the last trimester until 18 months postdelivery was crucial for brain growth and neurodevelopment, with 76.8% believing that infants breast-fed by vegan mothers have an increased risk of impaired brain development. CONCLUSION The results of this study show that practicing physicians significantly agree that nutrition plays an important role in brain and cognitive development and function in early childhood, particularly during the last trimester until 18 months postdelivery.
Collapse
Affiliation(s)
- Yvan Vandenplas
- KidZ Health Castle, UZ Brussel, Vrije Universiteit Brussel, Brussels, Belgium
| | | | - Amira Edris
- Department of Pediatrics, Kasr Al Ainy Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Bassel Shaaban
- Departments of Pediatric and NICU, Mediclinic Airport Road Hospital, Abu Dhabi, UAE
| | - Eslam Tawfik
- Department of Pediatric, Sheikh Khalifa Medical City, Abu Dhabi, UAE
| | - Fahad A Bashiri
- Division of Neurology, Department of Pediatrics, College of Medicine & King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia
| | - Fahd AlAql
- King Fahad Medical City, Riyadh, Kingdom of Saudi Arabia
| | | | - Joseph Haddad
- Department of Pediatrics, Saint George Hospital, University Medical Center, Balamand University, Beirut, Lebanon
| | - Mohammed El Barbary
- Department of Pediatrics and Neonatology, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | | | | | - Mudit Kumar
- Consultant Pediatrician, Mediclinic Parkview Hospital, Dubai, UAE
| | - Sulaiman Alsaad
- Department of Pediatrics, Neonatal Intensive Care Unit, Kuwait Oil Company Hospital, Al Ahmadi City, Kuwait
| |
Collapse
|
5
|
Dold S, Zimmermann MB, Baumgartner J, Davaz T, Galetti V, Braegger C, Andersson M. A dose-response crossover iodine balance study to determine iodine requirements in early infancy. Am J Clin Nutr 2016; 104:620-8. [PMID: 27465383 DOI: 10.3945/ajcn.116.134049] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 06/16/2016] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Optimal iodine intake during infancy is critical for brain development, but no estimated average requirement (EAR) is available for this age group. OBJECTIVE We measured daily iodine intake, excretion, and retention over a range of iodine intakes in early infancy to determine the minimum daily intake required to achieve iodine balance. DESIGN In a dose-response crossover study, we randomly assigned healthy infants (n = 11; mean ± SD age 13 ± 3 wk) to sequentially consume over 33 d 3 infant formula milks (IFMs) containing 10.5, 19.3, and 38.5 μg I/100 kcal, respectively. Each IFM was consumed for 11 d, consisting of a 6-d run-in period followed by a 4-d balance period and 1 run-out day. RESULTS Iodine intake (mean ± SD: 54.6 ± 8.1, 142.3 ± 23.1, and 268.4 ± 32.6 μg/d), excretion (55.9 ± 8.6, 121.9 ± 21.7, and 228.7 ± 39.3 μg/d), and retention (-1.6 ± 8.3, 20.6 ± 21.6, and 39.8 ± 34.3 μg/d) differed among the low, middle, and high iodine IFM groups (P < 0.001 for all). There was a linear relation between daily iodine intake and both daily iodine excretion and daily iodine retention. Zero balance (iodine intake = iodine excretion, iodine retention = 0 μg/d) was achieved at a daily iodine intake of 70 μg (95% CI: 60, 80 μg). CONCLUSION Our data indicate the iodine requirement in 2- to 5-mo-old infants is 70 μg/d. Adding an allowance for accumulation of thyroidal iodine stores would produce an EAR of 72 μg and a recommended dietary allowance of 80 μg. This trial was registered at clinicaltrials.gov as NCT02045784.
Collapse
Affiliation(s)
- Susanne Dold
- Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich, Switzerland;
| | - Michael B Zimmermann
- Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich, Switzerland; Iodine Global Network, Zurich, Switzerland
| | - Jeannine Baumgartner
- Centre of Excellence for Nutrition, North-West University, Potchefstroom, South Africa; and
| | - Tabea Davaz
- Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Valeria Galetti
- Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Christian Braegger
- Division of Gastroenterology and Nutrition, University Children's Hospital, Zurich, Switzerland
| | - Maria Andersson
- Human Nutrition Laboratory, Institute of Food Nutrition and Health, ETH Zurich, Zurich, Switzerland; Iodine Global Network, Zurich, Switzerland
| |
Collapse
|
6
|
Samidurai AJ, Ware RS, Davies PSW. The Iodine Status of Queensland Preschool Children After the Introduction of Mandatory Iodine Fortification in Bread: An Exploratory Study Using a Convenience Sample. Matern Child Health J 2016; 21:215-221. [DOI: 10.1007/s10995-016-2111-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
7
|
Nepal AK, Suwal R, Gautam S, Shah GS, Baral N, Andersson M, Zimmermann MB. Subclinical Hypothyroidism and Elevated Thyroglobulin in Infants with Chronic Excess Iodine Intake. Thyroid 2015; 25:851-9. [PMID: 25950720 DOI: 10.1089/thy.2015.0153] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Acute iodine excess in newborns can cause hypothyroidism, but there are limited data on the effects of iodine excess on thyroid function in older infants. The aim of this study was to measure the effects of chronic excess iodine intake on thyroid function in 6-24-month-old infants. METHODS In this cross-sectional study, infants (n=696) in eastern Nepal were studied. Spot urine samples, venous blood samples, and household salt samples were collected, and urinary iodine concentration (UIC), serum free thyroxine (fT4), thyrotropin (TSH), thyroglobulin (Tg), and titrated household salt iodine concentration (SIC) were measured. Daily iodine intake was calculated from UIC based on estimates of urine volume at this age. RESULTS Median (25th-75th percentile) household SIC was 89 (70-149) ppm, while national legislation stipulates a fortification level of 50 ppm. Median UIC was 407 (312-491) μg/L; 76% of infants had a UIC >300 μg/L, suggesting iodine excess. Calculated mean iodine intake in 12-24-month-old infants was 220 μg/day, exceeding the recommended safe upper limit for iodine at this age (200 μg/day). Among the infants, 15.8% had an elevated Tg, 7.4% had subclinical hypothyroidism, but <1% had overt hypothyroidism. UIC was not a significant predictor of thyroid function, thyroid hormones, or Tg. CONCLUSION In 6-24-month-old infants exposed to excessive iodine intake, ∼7% have subclinical hypothyroidism but <1% have overt hypothyroidism. These findings suggest the thyroid in late infancy is already able to adapt to high iodine intakes and, in most cases, maintain euthyroidism.
Collapse
Affiliation(s)
- Ashwini Kumar Nepal
- 1 Department of Biochemistry, B.P. Koirala Institute of Health Sciences , Dharan, Nepal
| | - Ranjan Suwal
- 1 Department of Biochemistry, B.P. Koirala Institute of Health Sciences , Dharan, Nepal
| | - Sharad Gautam
- 1 Department of Biochemistry, B.P. Koirala Institute of Health Sciences , Dharan, Nepal
| | - Gauri Shankar Shah
- 2 Department of Pediatric and Adolescent Medicine, B.P. Koirala Institute of Health Sciences , Dharan, Nepal
| | - Nirmal Baral
- 1 Department of Biochemistry, B.P. Koirala Institute of Health Sciences , Dharan, Nepal
| | - Maria Andersson
- 3 Human Nutrition Laboratory, Institute of Food Nutrition and Health, Swiss Federal Institute of Technology (ETH) , Zurich, Switzerland
| | - Michael Bruce Zimmermann
- 3 Human Nutrition Laboratory, Institute of Food Nutrition and Health, Swiss Federal Institute of Technology (ETH) , Zurich, Switzerland
| |
Collapse
|
8
|
Lean MIFA, Lean MEJ, Yajnik CS, Bhat DS, Joshi SM, Raut DA, Lubree HG, Combet E. Iodine status during pregnancy in India and related neonatal and infant outcomes. Public Health Nutr 2014; 17:1353-62. [PMID: 23659491 PMCID: PMC10282493 DOI: 10.1017/s1368980013001201] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 03/09/2013] [Accepted: 03/15/2013] [Indexed: 11/07/2022]
Abstract
OBJECTIVE To document iodine status in Indian pregnancies, associations with maternal diet and demographics, and offspring developmental measures. DESIGN Longitudinal study following mothers through pregnancy and offspring up to 24 months. SETTING Rural health-care centre (Vadu) and urban antenatal clinic (Pune) in the Maharashtra region of India. SUBJECTS Pregnant mothers at 17 (n 132) and 34 weeks' (n 151) gestation and their infants from birth to the age of 24 months. RESULTS Median urinary iodine concentration (UIC) was 203 and 211 μg/l at 17 and 34 weeks of pregnancy, respectively (range 26-800 μg/l). Using the UIC distribution adjusted for within-person variation, extreme UIC quartiles were compared for predictors and outcomes. There was no correlation between UIC at 17 and 34 weeks, but 24 % of those with UIC in the lowest quartile at 17 weeks had UIC in the same lowest quartile at 34 weeks. Maternal educational, socio-economic status and milk products consumption (frequency) were different between the lowest and highest quartile of UIC at 34 weeks. Selected offspring developmental outcomes differed between the lowest and highest UIC quartiles (abdominal circumference at 24 months, subscapular and triceps skinfolds at 12 and 24 months). However, UIC was only a weak predictor of subscapular skinfold at 12 months and of triceps skinfold at 24 months. CONCLUSIONS Median UIC in this pregnant population suggested adequate dietary provision at both gestational stages studied. Occasional high results found in spot samples may indicate intermittent consumption of iodine-rich foods. Maternal UIC had limited influence on offspring developmental outcomes.
Collapse
Affiliation(s)
- Morven IFA Lean
- Human Nutrition, Glasgow School of Medicine, University of Glasgow, Glasgow, UK
| | - Mike EJ Lean
- Human Nutrition, Glasgow School of Medicine, University of Glasgow, Glasgow, UK
- College of Medical, Veterinary & Life Sciences, School of Medicine, Human Nutrition, 4th Floor Walton Building, Glasgow Royal Infirmary, 84 Castle Street, Glasgow G4 0SF, UK
| | | | - Dattatray S Bhat
- Kamalnayan Bajaj Diabetology Research Centre, King Edward Memorial Hospital Research Centre, Pune, India
| | - Suyog M Joshi
- Kamalnayan Bajaj Diabetology Research Centre, King Edward Memorial Hospital Research Centre, Pune, India
| | - Deepa A Raut
- Kamalnayan Bajaj Diabetology Research Centre, King Edward Memorial Hospital Research Centre, Pune, India
| | - Himangi G Lubree
- Kamalnayan Bajaj Diabetology Research Centre, King Edward Memorial Hospital Research Centre, Pune, India
| | - Emilie Combet
- Human Nutrition, Glasgow School of Medicine, University of Glasgow, Glasgow, UK
| |
Collapse
|
9
|
|
10
|
Skeaff S, Zhao Y, Gibson R, Makrides M, Zhou SJ. Iodine status in pre-school children prior to mandatory iodine fortification in Australia. MATERNAL & CHILD NUTRITION 2014; 10:304-12. [PMID: 22642303 PMCID: PMC6860215 DOI: 10.1111/j.1740-8709.2012.00419.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The iodine status of children between the ages of 5 and 15 years has been routinely assessed in many countries, but few studies have examined iodine status in pre-school children. We conducted a cross-sectional study of pre-school children living in Adelaide, South Australia, between 2005 and 2007. Children 1-5 years old were identified using a unique sampling strategy to ensure that the study population was representative. A 3-day weighed diet record, a blood sample and a urine sample were obtained from each child. The median urinary iodine concentration (UIC) of the children (n = 279) was 129 µg L(-1), indicating iodine sufficiency (normal range: 100-199 µg L(-1)), but 35% of the children had a UIC < 100 µg L(-1). The median thyroglobulin concentration of children (n = 217) was 24 µg L(-1) and thyroglobulin concentration declined with increasing age (P = 0.024). The mean daily iodine intake was 76 µg. The intake of iodine was lower than expected and highlights difficulties in accurately assessing iodine intakes. Further studies are needed to monitor dietary changes and iodine status in this age group since the implementation of mandatory fortification of bread with iodised salt in Australia in 2009.
Collapse
Affiliation(s)
- Sheila Skeaff
- Department of Human Nutrition, University of Otago, Dunedin, New Zealand
| | - Ying Zhao
- Department of Human Nutrition, University of Otago, Dunedin, New Zealand
| | - Robert Gibson
- School of Agriculture, Food & Wine, University of Adelaide., Waite Campus, Glen Osmond, South Australia, Australia
| | - Maria Makrides
- Women's and Children's Health Research Institute, School of Paediatrics & Reproductive Health, University of Adelaide, North Adelaide, South Australia, Australia
| | - Shao Jia Zhou
- Women's and Children's Health Research Institute, School of Paediatrics & Reproductive Health, University of Adelaide, North Adelaide, South Australia, Australia
| |
Collapse
|
11
|
Scientific Opinion on nutrient requirements and dietary intakes of infants and young children in the European Union. EFSA J 2013. [DOI: 10.2903/j.efsa.2013.3408] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
12
|
Untoro J, Timmer A, Schultink W. The challenges of iodine supplementation: a public health programme perspective. Best Pract Res Clin Endocrinol Metab 2010; 24:89-99. [PMID: 20172473 DOI: 10.1016/j.beem.2009.08.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
An adequate iodine intake during pregnancy, lactation and early childhood is particularly critical for optimal brain development of the foetus and of children 7-24 months of age. While the primary strategy for sustainable elimination of iodine deficiency remains universal salt iodisation, the World Health Organization and the United Nations Children's Fund recommend a complementary strategy of iodine supplements as a temporary measure when salt iodisation could not be implemented. This article aims to review current evidence on efficacy and implications of implementing iodine supplementation as a public health measure to address iodine deficiency. Iodine supplementation seems unlikely to reach high coverage in a rapid, equitable and sustained way. Implementing the programme requires political commitment, effective and efficient supply, distribution and targeting, continuous education and communication and a robust monitoring system. Thus, universal salt iodisation should remain the primary strategy to eliminate iodine deficiency.
Collapse
|
13
|
Pouessel G, Damie R, Soudan B, Weill J, Gottrand F, Turck D. Statut en iode chez des enfants de moins de 1 an : conséquences sur la fonction thyroïdienne. Arch Pediatr 2008; 15:1276-82. [DOI: 10.1016/j.arcped.2008.04.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2007] [Revised: 02/28/2008] [Accepted: 04/13/2008] [Indexed: 10/21/2022]
|
14
|
Iodine requirements during pregnancy, lactation and the neonatal period and indicators of optimal iodine nutrition. Public Health Nutr 2008; 10:1571-80; discussion 1581-3. [PMID: 18053281 DOI: 10.1017/s1368980007360941] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE This paper re-evaluates the requirements for iodine during pregnancy, lactation and the neonatal period, and formulates original proposals for the median concentrations of urinary iodine (UI) that indicate optimal iodine nutrition during these three critical periods of life. This paper also discusses the measurements that are used to explore thyroid functions during the same periods. DESIGN An extensive and critical review of the literature on thyroid physiopathology during the perinatal period. SETTING Human studies conducted in various regions throughout the world. SUBJECTS Pregnant women, lactating women, and newborns. RESULTS The following proposals are made after extensive review of the literature: the requirement for iodine by the mother during pregnancy is 250-300 microg day-1; during lactation the requirement is 225-350 microg day-1; and during the neonatal period the requirement of the infant is 90 microg day-1. The median UI that indicates an optimal iodine nutrition during these three periods should be in the range of 150-230 microg day-1. These figures are higher than recommended to date by the international agencies. CONCLUSIONS Pregnant women and young infants, but especially the second group, are more sensitive to the effects of an iodine deficiency (ID) than the general population because their serum thyroid-stimulating hormone (TSH) and thyroxine are increased and decreased, respectively, for degrees of ID that do not seem to affect thyroid function in the general population. Systematic neonatal thyroid screening using primary TSH could be the most sensitive indicator to monitor the process of ID control.
Collapse
|
15
|
The impact of iodised salt or iodine supplements on iodine status during pregnancy, lactation and infancy. Public Health Nutr 2007; 10:1584-95. [DOI: 10.1017/s1368980007360965] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractObjectives:Monitoring of iodine status during pregnancy, lactation and infancy is difficult as there are no established reference criteria for urinary iodine concentration (UI) for these groups; so it is uncertain whether iodized salt programs meet the needs of these life stages.Design and Subjects:The method used in this paper was: 1) to estimate the median UI concentration that reflects adequate iodine intake during these life stages; and 2) to use these estimates in a review of the literature to assess whether salt iodisation can control iodine deficiency in pregnant and lactating women, and their infants.Results:For pregnancy, recommended mean daily iodine intakes of 220-250 μg were estimated to correspond to a median UI concentration of about 150 μg l− 1, and larger surveys from the iodine sufficient countries have reported a median UI in pregnant women ≥ 140 μg l− 1. Iodine supplementation in pregnant women who are mild-to-moderately iodine deficient is beneficial, but there is no clear affect on maternal or newborn thyroid hormone levels. In countries where the iodine intake is sufficient, most mothers have median breast milk iodine concentration (BMIC) greater than the concentration (100-120 μg l− 1) required to meet an infant's needs. The median UI concentration during infancy that indicates optimal iodine nutrition is estimated to be ≥ 100 μg l− 1. In iodine-sufficient countries, the median UI concentration in infants ranges from 90-170 μg l− 1, suggesting adequate iodine intake in infancy.Conclusions:These findings suggest pregnant and lactating women and their infants in countries with successful sustained iodised salt programs have adequate iodine status.
Collapse
|
16
|
Dlouhý P, Rambousková J, Wiererová O, Pokorný R, Bílek R, Kubisová D, Procházka B, Andel M. Iodine Saturation of Roma Neonates in Prague Is Not at an Optimum Level. ANNALS OF NUTRITION AND METABOLISM 2006; 50:242-6. [PMID: 16508251 DOI: 10.1159/000091681] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2005] [Accepted: 09/08/2005] [Indexed: 11/19/2022]
Abstract
AIM The purpose of our study was to determine urinary iodine as an indicator of iodine supplementation in Roma (Gypsy) neonates compared to majority population neonates. METHODS The groups studied were formed by 30 full-term Roma neonates and 151 majority population neonates. Iodine was determined from samples of urine collected on the 4th day after delivery, after alkaline ashing, using the Sandell-Kolthoff method. RESULTS The median of urinary iodine in Roma neonates was 92.15 microg/l urine and in neonates from majority population mothers it was 109.20 microg/l urine. The mean of urinary iodine in Roma neonates was 114.55 microg/l urine (SD 71.68 microg/l) and in neonates from majority population mothers it was 141.86 microg/l urine (SD 87.42 microg/l). The difference was not statistically significant. Majority population mothers more frequently consumed nutrition supplements containing iodine as well as fish. CONCLUSIONS Compared to older data, supplementation of neonates with iodine is higher. However, it does not reach optimum levels. The urinary iodine median in Roma neonates lies in the mild iodine deficiency band.
Collapse
Affiliation(s)
- P Dlouhý
- Division of Nutrition, 3rd Faculty of Medicine, Charles University, Prague, Czech Republic.
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Abstract
This overview of multiple micronutrients during pregnancy and lactation emphasizes 2 relatively neglected issues. The first is that maternal micronutrient status in the periconceptional period, and throughout pregnancy and lactation, should be viewed as a continuum; too often these 3 stages are treated and discussed separately from both a scientific and a public health perspective. Iron and vitamin B-12 are included as examples to stress how status at conception affects maternal, fetal, and infant status and health until the child is weaned. The second issue is that while most attention has been focused on a few micronutrients, for example iron and folate as discussed elsewhere in this Supplement, multiple micronutrient deficiencies occur simultaneously when diets are poor. Some of these deserve more attention as causes of poor pregnancy outcome, including other B vitamin deficiencies that result in homocysteinemia, antioxidants, vitamin D, and iodine. In lactation, maternal status or intake of the B vitamins (except folate), vitamin A, selenium and iodine strongly affect the amount of these nutrients secreted in breast milk. This can result in the infant consuming substantially less than the recommended amounts and further depleting stores that were low at birth. While the optimal mode of meeting recommended micronutrient intakes is an adequate diet, in some situations supplementation is also important. Unfortunately, information is lacking on the optimal formulation of micronutrient supplements for pregnant women, and the need to continue these supplements during lactation is not recognized in many situations where maternal and infant health could benefit.
Collapse
Affiliation(s)
- Lindsay H Allen
- US Department of Agriculture, ARS-Western Human Nutrition Research Center, and Department of Nutrition, University of California, Davis, CA, USA.
| |
Collapse
|
18
|
Skeaff SA, Ferguson EL, McKenzie JE, Valeix P, Gibson RS, Thomson CD. Are breast-fed infants and toddlers in New Zealand at risk of iodine deficiency? Nutrition 2005; 21:325-31. [PMID: 15797674 DOI: 10.1016/j.nut.2004.07.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2003] [Accepted: 07/07/2004] [Indexed: 11/22/2022]
Abstract
OBJECTIVE This study assessed the iodine status of New Zealand infants and toddlers and explored factors that might influence their iodine status. METHODS A community-based, cross-sectional survey of 6- to 24-mo-old children was conducted in three cities in the South Island of New Zealand. Iodine status was determined by a casual urine sample. Breast-feeding mothers were asked to provide a breast milk sample for iodine determination. Caregivers collected a 3-d weighed diet record from their children to investigate associations between dietary patterns and urinary iodine excretion. RESULTS The median urinary iodine concentration for the group (n = 230) was 67 microg/L (interquartile range 37-115) with 37% (95% confidence interval 30.5-43.4) of children having a urinary iodine concentration lower than 50 microg/L. When children were classified by current feeding method, those children who were currently formula-fed had a significantly higher median urinary iodine concentration (99 microg/L) than did children who were currently breast-fed (44 microg/L; P < 0.000). The mean iodine concentration in breast milk was 22 microg/L (n = 39). After multivariate analysis using estimates from 3-d diet records, only percentage of energy from infant formula was significantly associated with urinary iodine concentration (P = 0.005). CONCLUSIONS This study found mild iodine deficiency in a group of New Zealand infants and toddlers. Children who consumed infant formula, which is fortified with iodine, had better iodine status than did children who were currently breast-fed because breast milk contained low levels of iodine.
Collapse
Affiliation(s)
- Sheila A Skeaff
- Department of Human Nutrition, University of Otago, Dunedin, New Zealand
| | | | | | | | | | | |
Collapse
|
19
|
Kibirige MS, Hutchison S, Owen CJ, Delves HT. Prevalence of maternal dietary iodine insufficiency in the north east of England: implications for the fetus. Arch Dis Child Fetal Neonatal Ed 2004; 89:F436-9. [PMID: 15321965 PMCID: PMC1721745 DOI: 10.1136/adc.2003.029306] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Maternal subclinical hypothyroidism is a cause of poor neurodevelopment outcome in the offspring. Although iodine deficiency is the most common cause of hypothyroidism world wide, there are no screening programmes for it in the United Kingdom where the population is assumed to be iodine replete. OBJECTIVE To determine the prevalence of reduced iodine intake by measuring urinary iodide concentrations in pregnant and non-pregnant women from the north east of England. METHODS Urinary iodide excretion (UIE) rate was estimated using inductively coupled mass spectrometry in 227 women at 15 weeks gestation and in 227 non-pregnant age matched controls. A reduced intake of iodine is indicated by a concentration in urine of less than 50 microg/l or less than 0.05 microg iodine/mmol creatinine. RESULTS Eight (3.5%) pregnant women and 13 (5.7%) controls had a reduced iodine/creatinine ratio. These values were higher when UIE was expressed as iodine concentration: 16 (7%) and 20 (8.8%) respectively. Ninety (40%) of the pregnant women had a UIE of 0.05-0.10, which is consistent with borderline deficiency. CONCLUSION In this study, 3.5% of pregnant women had evidence of iodine deficiency, and 40% may be borderline deficient. Larger scale studies are required to estimate the true prevalence of iodine deficiency in the United Kingdom.
Collapse
Affiliation(s)
- M S Kibirige
- The James Cook University Hospital, Middlesbrough TS4 3BW, UK.
| | | | | | | |
Collapse
|
20
|
Rossi L, Branca F. Salt iodisation and public health campaigns to eradicate iodine deficiency disorders in Armenia. Public Health Nutr 2003; 6:463-9. [PMID: 12943562 DOI: 10.1079/phn2003461] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Iodine deficiency disorders (IDD) are endemic in the mountain regions of Armenia. Universal salt iodisation has been chosen as the control measure. OBJECTIVES (1). To measure the prevalence of iodine deficiency in the Armenian population; (2). to evaluate household use of iodised salt; and (3). to monitor iodised salt promotion strategies. DESIGN Cross-sectional study on a nationally representative sample of 2627 households, including 3390 children under five and 2649 women of fertile age. Cluster sampling design on four population strata: residents, refugees, rural and urban. RESULTS Thyroid was palpable in one-third of the women, 6% of them having a visible goitre. Median of urinary iodine excretion in children was 139.5 microg l-1. One-third of the children showed low urinary iodine concentration. Iodised salt was consumed in 66% of the households. The national IDD control programme included modernisation of the Yerevan Salt Factory, legislative regulation of the iodine content of the salt, and public information by the media. CONCLUSIONS Armenia was still an endemic zone for goitre in 1997. The iodine status of children under five in 1997 was not considered alarming even though 33% of them had low values of urinary iodine. After four years of intervention strategies, the use of iodised salt has increased by 17%. Further efforts should be made to control salt imports and to monitor IDD indicators in vulnerable groups.
Collapse
Affiliation(s)
- Laura Rossi
- Human Nutrition Unit, National Institute for Research on Food and Nutrition, via Ardeatina 546, 00178, Rome, Italy
| | | |
Collapse
|
21
|
Pouessel G, Bouarfa K, Soudan B, Sauvage J, Gottrand F, Turck D. [Iodine nutritional status and risk factors for iodine deficiency in infants and children of the french North department]. Arch Pediatr 2003; 10:96-101. [PMID: 12829349 DOI: 10.1016/s0929-693x(03)00304-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
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.
Collapse
Affiliation(s)
- G Pouessel
- Unité de gastro-entérologie, hépatologie et nutrition, clinique de pédiatrie, hôpital Jeanne-de-Flandre, 2, avenue Oscar-Lambret, 59037 Lille cedex, France
| | | | | | | | | | | |
Collapse
|