As a component of thyroid hormones, adequate iodine intake is essential during pregnancy for fetal neurodevelopment. Across Europe, iodine deficiency is common in pregnancy, but data are lacking on the predictors of iodine status at this life stage. We, therefore, aimed to explore determinants of iodine status during pregnancy in three European populations of differing iodine status.
Data were from 6566 pregnant women from three prospective population-based birth cohorts from the United Kingdom (ALSPAC, n = 2852), Spain (INMA, n = 1460), and The Netherlands (Generation R, n = 2254). Urinary iodine-to-creatinine ratio (UI/Creat, µg/g) was measured in spot-urine samples in pregnancy (≤ 18-weeks gestation). Maternal dietary intake, categorised by food groups (g/day), was estimated from food-frequency questionnaires (FFQs). Multivariable regression models used dietary variables (energy-adjusted) and maternal characteristics as predictors of iodine status.
Median UI/Creat in pregnant women of ALSPAC, INMA, and Generation R was 121, 151, and 210 µg/g, respectively. Maternal age was positively associated with UI/Creat in all cohorts (P < 0.001), while UI/Creat varied by ethnicity only in Generation R (P < 0.05). Of the dietary predictors, intake of milk and dairy products (per 100 g/day) was positively associated with UI/Creat in all cohorts [ALSPAC (B = 3.73, P < 0.0001); INMA (B = 6.92, P = 0.002); Generation R (B = 2.34, P = 0.001)]. Cohort-specific dietary determinants positively associated with UI/Creat included fish and shellfish in ALSPAC and INMA, and eggs and cereal/cereal products in Generation R.
The cohort-specific dietary determinants probably reflect not only dietary habits but iodine-fortification policies; hence, public-health interventions to improve iodine intake in pregnancy need to be country-specific.
This is a preview of subscription content, access via your institution.
Buy single article
Instant access to the full article PDF.
Tax calculation will be finalised during checkout.
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
Tax calculation will be finalised during checkout.
The Avon Longitudinal Study of Parents and Children
Body mass index
Certified reference material
INfancia y Medio Ambiente
Relative standard deviation
Standard error of estimate
Semi-quantitative food-frequency questionnaire
Urinary iodine-to-creatinine ratio
Urinary iodine concentration
World Health Organisation
de Escobar GM, Obregón MJ, del Rey FE (2004) Maternal thyroid hormones early in pregnancy and fetal brain development. Best Pract Res Clin Endocrinol Metab 18:225–248. https://doi.org/10.1016/j.beem.2004.03.012
Glinoer D (2007) The importance of iodine nutrition during pregnancy. Public Health Nutr 10:1542–1546. https://doi.org/10.1017/S1368980007360886
van Mil NH, Tiemeier H, Bongers-Schokking JJ, Ghassabian A, Hofman A, Hooijkaas H, Jaddoe VWV, de Muinck Keizer-Schrama SM, Steegers EAP, Visser TJ, Visser W, Ross HA, Verhulst FC, de Rijke YB, Steegers-Theunissen RPM (2012) Low urinary iodine excretion during early pregnancy is associated with alterations in executive functioning in children. J Nutr 142:2167–2174. https://doi.org/10.3945/jn.112.161950
Bath SC, Steer CD, Golding J, Emmett P, Rayman MP (2013) Effect of inadequate iodine status in UK pregnant women on cognitive outcomes in their children: results from the Avon Longitudinal Study of Parents and Children (ALSPAC). Lancet 382:331–337. https://doi.org/10.1016/S0140-6736(13)60436-5
Hynes KL, Otahal P, Hay I, Burgess JR (2013) Mild iodine deficiency during pregnancy is associated with reduced educational outcomes in the offspring: 9-year follow-up of the gestational iodine cohort. J Clin Endocrinol Metab 98:1954–1962. https://doi.org/10.1210/jc.2012-4249
Hynes K, Otahal P, Burgess J, Oddy W, Hay I (2017) Reduced educational outcomes persist into adolescence following mild iodine deficiency in utero, despite adequacy in childhood: 15-year follow-up of the gestational iodine cohort investigating auditory processing speed and working memory. Nutrients 9:1354. https://doi.org/10.3390/nu9121354
Murcia M, Espada M, Julvez J, Llop S, Lopez-Espinosa M-J, Vioque J, Basterrechea M, Riaño I, González L, Alvarez-Pedrerol M, Tardón A, Ibarluzea J, Rebagliato M (2017) Iodine intake from supplements and diet during pregnancy and child cognitive and motor development: the INMA Mother and Child Cohort Study. J Epidemiol Community Health 0:1–7. https://doi.org/10.1136/jech-2017-209830
Williams GR (2008) Neurodevelopmental and neurophysiological actions of thyroid hormone. J Neuroendocrinol 20:784–794. https://doi.org/10.1111/j.1365-2826.2008.01733.x
Glinoer D (2004) The regulation of thyroid function during normal pregnancy: importance of the iodine nutrition status. Best Pract Res Clin Endocrinol Metab 18:133–152. https://doi.org/10.1016/J.BEEM.2004.03.001
Delange F (2007) Iodine requirements during pregnancy, lactation and the neonatal period and indicators of optimal iodine nutrition. Public Health Nutr 10:1571–1580. https://doi.org/10.1017/S1368980007360941
Zimmermann MB (2008) Methods to assess iron and iodine status. Br J Nutr 99:S2–S9. https://doi.org/10.1017/S000711450800679X
World Health Organisation (2007) Assessment of iodine deficiency disorders and monitoring their elimination. A guide for programme managers. http://apps.who.int/iris/bitstream/10665/43781/1/9789241595827_eng.pdf. Accessed 20 Sep 2017
Rasmussen LB, Andersen S, Ovesen L, Laurberg P (2009) Iodine intake and food choice. In: Preedy VR, Burrow GN, Watson RR (eds) Comprehensive handbook of iodine: nutritional, biochemical, pathological and therapeutic aspects. Elsevier, London, pp 331–337
Haldimann M, Alt A, Blanc A, Blondeau K (2005) Iodine content of food groups. J Food Compos Anal 18:461–471. https://doi.org/10.1016/j.jfca.2004.06.003
Iodine Global Network (2017) Global Scorecard of Iodine Nutrition in 2017 in the general population and in pregnant women (PW). http://www.ign.org/cm_data/IGN_Global_Scorecard_AllPop_and_PW_May2017.pdf. Accessed 24 Sep 2017
Boyd A, Golding J, Macleod J, Lawlor DA, Fraser A, Henderson J, Molloy L, Ness A, Ring S, Smith GD (2013) Cohort profile: The “Children of the 90s”—the index offspring of the avon longitudinal study of parents and children. Int J Epidemiol 42:111–127. https://doi.org/10.1093/ije/dys064
Fraser A, Macdonald-Wallis C, Tilling K, Boyd A, Golding J, Davey smith G, Henderson J, Macleod J, Molloy L, Ness A, Ring S, Nelson SM, Lawlor DA (2013) Cohort profile: The avon longitudinal study of parents and children: ALSPAC mothers cohort. Int J Epidemiol 42:97–110. https://doi.org/10.1093/ije/dys066
Kooijman MN, Kruithof CJ, van Duijn CM, Duijts L, Franco OH, van IJzendoorn MH, de Jongste JC, Klaver CCW, van der Lugt A, Mackenbach JP, Moll HA, Peeters RP, Raat H, Rings EHHM, Rivadeneira F, van der Schroeff MP, Steegers EAP, Tiemeier H, Uitterlinden AG, Verhulst FC, Wolvius E, Felix JF, Jaddoe VWV (2016) The generation R Study: design and cohort update 2017. Eur J Epidemiol 31:1243–1264. https://doi.org/10.1007/s10654-016-0224-9
Guxens M, Ballester F, Espada M, Fernández MF, Grimalt JO, Ibarluzea J, Olea N, Rebagliato M, Tardón A, Torrent M, Vioque J, Vrijheid M, Sunyer J (2012) Cohort profile: the INMA—INfancia y Medio Ambiente—(Environment and Childhood) Project. Int J Epidemiol 41:930–940. https://doi.org/10.1093/ije/dyr054
ALSPAC (2018) Data dictionary. http://www.bristol.ac.uk/alspac/researchers/our-data/. Accessed 20 Mar 2018
Ghassabian A, Steenweg-de Graaff J, Peeters RP, Ross HA, Jaddoe VW, Hofman A, Verhulst FC, White T, Tiemeier H (2014) Maternal urinary iodine concentration in pregnancy and children’s cognition: results from a population-based birth cohort in an iodine-sufficient area. BMJ Open 4:e005520–e005520. https://doi.org/10.1136/bmjopen-2014-005520
Murcia M, Rebagliato M, Espada M, Vioque J, Santa Marina L, Alvarez-Pedrerol M, Lopez-Espinosa M-J, León G, Iñiguez C, Basterrechea M, Guxens M, Lertxundi A, Perales A, Ballester F, Sunyer J, INMA Study Group (2010) Iodine intake in a population of pregnant women: INMA mother and child cohort study, Spain. J Epidemiol Community Health 64:1094–1099. https://doi.org/10.1136/jech.2009.092593
Stiles J, Jernigan TL (2010) The basics of brain development. Neuropsychol Rev 20:327–348. https://doi.org/10.1007/s11065-010-9148-4
Vejbjerg P, Knudsen N, Perrild H, Laurberg P, Andersen S, Rasmussen LB, Ovesen L, Jørgensen T (2009) Estimation of iodine intake from various urinary iodine measurements in population studies. Thyroid 19:1281–1286. https://doi.org/10.1089/thy.2009.0094
König F, Andersson M, Hotz K, Aeberli I, Zimmermann MB (2011) Ten repeat collections for urinary iodine from spot samples or 24-h samples are needed to reliably estimate individual iodine status in women. J Nutr 141:2049–2054. https://doi.org/10.3945/jn.111.144071
Andersen S, Karmisholt J, Pedersen KM, Laurberg P (2008) Reliability of studies of iodine intake and recommendations for number of samples in groups and in individuals. Br J Nutr 99:813–818. https://doi.org/10.1017/S0007114507842292
Rasmussen LB, Ovesen L, Christiansen E (1999) Day-to-day and within-day variation in urinary iodine excretion. Eur J Clin Nutr 53:401–407
Pearce EN, Lazarus JH, Smyth PP, He X, Smith DF, Pino S, Braverman LE (2009) Urine test strips as a source of iodine contamination. Thyroid. https://doi.org/10.1089/thy.2009.0120
Pearce EN, Lazarus JH, Smyth PPA, He X, Dall’Amico D, Parkes AB, Burns R, Smith DF, Maina A, Bestwick JP, Jooman M, Leung AM, Braverman LE (2010) Perchlorate and thiocyanate exposure and thyroid function in first-trimester pregnant women. J Clin Endocrinol Metab 95:3207–3215. https://doi.org/10.1210/jc.2010-0014
Bath SC, Pop VJM, Furmidge-Owen VL, Broeren MAC, Rayman MP (2017) Thyroglobulin as a functional biomarker of iodine status in a cohort study of pregnant women in the United Kingdom. Thyroid 27:426–433. https://doi.org/10.1089/thy.2016.0322
Emmett P, Symes C, Braddon F, Heaton K (1992) Validation of a new questionnaire for assessing habitual intakes of starch, non-starch poly-saccharides, sugars and alcohol. J Hum Nutr Diet 5:245–254
Rogers I, Emmett P, ALSPAC Study Team (1998) Diet during pregnancy in a population of pregnant women in South West England. Eur J Clin Nutr 52:246–250
Klipstein-Grobusch K, den Breeijen JH, Goldbohm R, Geleijnse JM, Hofman A, Grobbee DE, Witteman JC (1998) Dietary assessment in the elderly: validation of a semiquantitative food frequency questionnaire. Eur J Clin Nutr 52:588–596. https://doi.org/10.1038/sj.ejcn.1600611
Timmermans S, Steegers-Theunissen RPM, Vujkovic M, Bakker R, Den Breeijen H, Raat H, Russcher H, Lindemans J, Hofman A, Jaddoe VWV, Steegers EAP (2011) Major dietary patterns and blood pressure patterns during pregnancy: the Generation R study. Am J Obstet Gynecol 205:337.e1–337.e12. https://doi.org/10.1016/j.ajog.2011.05.013
Steenweg-de Graaff J, Tiemeier H, Steegers-Theunissen RPM, Hofman A, Jaddoe VWV, Verhulst FC, Roza SJ (2014) Maternal dietary patterns during pregnancy and child internalising and externalising problems. The Generation R Study. Clin Nutr 33:115–121. https://doi.org/10.1016/j.clnu.2013.03.002
Slimani N, Fahey M, Welch A, Wirfält E, Stripp C, Bergström E, Linseisen J, Schulze M, Bamia C, Chloptsios Y, Veglia F, Panico S, Bueno-de-Mesquita H, Ocké M, Brustad M, Lund E, González C, Barcos A, Berglund G, Winkvist A, Mulligan A, Appleby P, Overvad K, Tjønneland A, Clavel-Chapelon F, Kesse E, Ferrari P, Van Staveren W, Riboli E (2002) Diversity of dietary patterns observed in the European Prospective Investigation into Cancer and Nutrition (EPIC) project. Public Health Nutr 5:1311. https://doi.org/10.1079/PHN2002407
Willett WC, Sampson L, Stampfer MJ, Rosner B, Bain C, Witschi J, Hennekens CH, Speizer FE (1985) Reproducibility and validity of a semiquantitative food frequency questionnaire. Am J Epidemiol 122:51–65. https://doi.org/10.1093/acprof
Vioque J, Weinbrenner T, Asensio L, Castelló A, Young IS, Fletcher A (2007) Plasma concentrations of carotenoids and vitamin C are better correlated with dietary intake in normal weight than overweight and obese elderly subjects. Br J Nutr 97:977. https://doi.org/10.1017/S0007114507659017
Vioque J, Navarrete-Muñoz E-M, Gimenez-Monzó D, García-de-la-Hera M, Granado F, Young IS, Ramón R, Ballester F, Murcia M, Rebagliato M, Iñiguez C (2013) Reproducibility and validity of a food frequency questionnaire among pregnant women in a Mediterranean area. Nutr J 12:26. https://doi.org/10.1186/1475-2891-12-26
Bowen E, Heron J, Waylen A, Wolke D (2005) Domestic violence risk during and after pregnancy: findings from a British longitudinal study. BJOG An Int J Obstet Gynaecol 112:1083–1089. https://doi.org/10.1111/j.1471-0528.2005.00653.x
Winsper C, Zanarini M, Wolke D (2012) Prospective study of family adversity and maladaptive parenting in childhood and borderline personality disorder symptoms in a non-clinical population at 11 years. Psychol Med 42:2405–2420. https://doi.org/10.1017/S0033291712000542
Barr DB, Wilder LC, Caudill SP, Gonzalez AJ, Needham LL, Pirkle JL (2005) Urinary creatinine concentrations in the U.S. population: implications for urinary biologic monitoring measurements. Environ Health Perspect 113:192–200. https://doi.org/10.1289/ehp.7337
Baba Y, Furuta I, Zhai T, Ohkuchi A, Yamada T, Takahashi K, Matsubara S, Minakami H (2017) Effect of urine creatinine level during pregnancy on dipstick test. J Obstet Gynaecol Res 43:967–973. https://doi.org/10.1111/jog.13327
Sterne JAC, White IR, Carlin JB, Spratt M, Royston P, Kenward MG, Wood AM, Carpenter JR (2009) Multiple imputation for missing data in epidemiological and clinical research: potential and pitfalls. BMJ 338:b2393. https://doi.org/10.1136/BMJ.B2393
Crawley H, Mills A, Patel S, Great B (1993) Ministry of agriculture F and F. In: Food portion sizes. H.M.S.O, London
World Health Organisation (2007) Iodine deficiency in Europe: a continuing public health problem. http://apps.who.int/iris/handle/10665/43398. Accessed 1 Oct 2017
Phillips DI (1997) Iodine, milk, and the elimination of endemic goitre in Britain: the story of an accidental public health triumph. J Epidemiol Community Health 51:391–393
Bath SC, Button S, Rayman MP (2014) Availability of iodised table salt in the UK—is it likely to influence population iodine intake? Public Health Nutr 17:450–454. https://doi.org/10.1017/S1368980012005496
Glinoer D (1997) The regulation of thyroid function in pregnancy: pathways of endocrine adaptation from physiology to pathology. Endocr Rev 18:404–433. https://doi.org/10.1210/edrv.18.3.0300
Cheung KL, Lafayette RA (2013) Renal physiology of pregnancy. Adv Chronic Kidney Dis 20:209–214. https://doi.org/10.1053/j.ackd.2013.01.012
Fuse Y, Shishiba Y, Irie M (2013) Gestational changes of thyroid function and urinary iodine in thyroid antibody-negative Japanese women. Endocr J 60:1095–1106. https://doi.org/10.1507/endocrj.EJ13-0184
Bath SC, Furmidge-Owen VL, Redman CW, Rayman MP (2015) Gestational changes in iodine status in a cohort study of pregnant women from the United Kingdom: season as an effect modifier. Am J Clin Nutr 101:1180–1187. https://doi.org/10.3945/ajcn.114.105536
Li C, Peng S, Zhang X, Xie X, Wang D, Mao J, Teng X, Shan Z, Teng W (2016) The urine iodine to creatinine as an optimal index of iodine during pregnancy in an iodine adequate area in China. J Clin Endocrinol Metab 101:1290–1298. https://doi.org/10.1210/jc.2015-3519
Brander L, Als C, Buess H, Haldimann F, Harder M, Hänggi W, Herrmann U, Lauber K, Niederer U, Zürcher T, Bürgi U, Gerber H (2003) Urinary iodine concentration during pregnancy in an area of unstable dietary iodine intake in Switzerland. J Endocrinol Invest 26:389–396. https://doi.org/10.1007/BF03345192
Stilwell G, Reynolds PJ, Parameswaran V, Blizzard L, Greenaway TM, Burgess JR (2008) The influence of gestational stage on urinary iodine excretion in pregnancy. J Clin Endocrinol Metab 93:1737–1742. https://doi.org/10.1210/jc.2007-1715
Gerchman F, Tong J, Utzschneider KM, Zraika S, Udayasankar J, McNeely MJ, Carr DB, Leonetti DL, Young BA, de Boer IH, Boyko EJ, Fujimoto WY, Kahn SE (2009) Body mass index is associated with increased creatinine clearance by a mechanism independent of body fat distribution. J Clin Endocrinol Metab 94:3781–3788. https://doi.org/10.1210/jc.2008-2508
O’Brien KM, Upson K, Cook NR, Weinberg CR (2016) Environmental chemicals in urine and blood: improving methods for creatinine and lipid adjustment. Environ Health Perspect 124:220–227
James GD, Sealey JE, Alderman M, Ljungman S, Mueller FB, Pecker MS, Laragh JH (1988) A longitudinal study of urinary creatinine and creatinine clearance in normal subjects: race, sex, and age differences. Am J Hypertens 1:124–131. https://doi.org/10.1093/ajh/1.2.124
Brantsæter AL, Haugen M, Julshamn K, Alexander J, Meltzer HM (2009) Evaluation of urinary iodine excretion as a biomarker for intake of milk and dairy products in pregnant women in the Norwegian Mother and Child Cohort Study (MoBa). Eur J Clin Nutr 63:347–354. https://doi.org/10.1038/sj.ejcn.1602952
Brantsæter AL, Abel MH, Haugen M, Meltzer HM (2013) Risk of suboptimal iodine intake in pregnant norwegian women. Nutrients 5:424–440. https://doi.org/10.3390/nu5020424
Gunnarsdottir I, Gustavsdottir AG, Steingrimsdottir L, Maage A, Johannesson AJ, Thorsdottir I (2013) Iodine status of pregnant women in a population changing from high to lower fish and milk consumption. Public Health Nutr 16:325–329. https://doi.org/10.1017/S1368980012001358
Mian C, Vitaliano P, Pozza D, Barollo S, Pitton M, Callegari G, Di Gianantonio E, Casaro A, Acamulli DN, Busnardo B, Mantero F, Girelli ME (2009) Iodine status in pregnancy: Role of dietary habits and geographical origin. Clin Endocrinol (Oxf) 70:776–780. https://doi.org/10.1111/j.1365-2265.2008.03416.x
Torres MT, Francés L, Vila L, Manresa JM, Falguera G, Prieto G, Casamitjana R, Toran P (2017) Iodine nutritional status of women in their first trimester of pregnancy in Catalonia. BMC Pregnancy Childbirth 17:249. https://doi.org/10.1186/s12884-017-1423-4
Bath SC, Walter A, Taylor A, Wright J, Rayman MP (2014) Iodine deficiency in pregnant women living in the South East of the UK: the influence of diet and nutritional supplements on iodine status. Br J Nutr 111:1622–1631. https://doi.org/10.1017/S0007114513004030
Blumenthal N, Byth K, Eastman CJ (2012) Iodine intake and thyroid function in pregnant women in a private clinical practice in Northwestern Sydney before mandatory fortification of bread with iodised salt. J Thyroid Res 2012:1–6. https://doi.org/10.1155/2012/798963
Soriguer F, Gutierrez-Repiso C, Gonzalez-Romero S, Olveira G, Garriga MJ, Velasco I, Santiago P, de Escobar GM, Garcia-Fuentes E, Iodine Deficiency Disorders Group of Spanish Society of Endocrinology and Nutrition (2011) Iodine concentration in cow’s milk and its relation with urinary iodine concentrations in the population. Clin Nutr 30:44–48. https://doi.org/10.1016/j.clnu.2010.07.001
National Institute for Public Health and the Environment (RIVM) (2016) Dutch food composition database (NEVO) online version 2016/5.0. In: RIVM, Bilthoven. http://nevo-online.rivm.nl/. Accessed 19 Jan 2018
Lee SM, Lewis J, Buss DH, Holcombe GD, Lawrance PR (1994) Iodine in British foods and diets. Br J Nutr 72:435. https://doi.org/10.1079/BJN19940045
Stevenson MC, Drake C, Givens DI (2018) Further studies on the iodine concentration of conventional, organic and UHT semi-skimmed milk at retail in the UK. Food Chem 239:551–555. https://doi.org/10.1016/J.FOODCHEM.2017.06.135
Dahl L, Johansson L, Julshamn K, Meltzer HM (2004) The iodine content of Norwegian foods and diets. Public Health Nutr 7:569–576. https://doi.org/10.1079/PHN2003554
Verkaik-Kloosterman J, Buurma-Rethans E, Dekkers A (2012) The iodine intake of children and adults in the Netherlands: Results of the Dutch National Food Consumption Survey 2007–2010—RIVM. http://www.rivm.nl/en/Documents_and_publications/Scientific/Reports/2012/april/The_iodine_intake_of_children_and_adults_in_the_Netherlands_Results_of_the_Dutch_National_Food_Consumption_Survey_2007_2010. Accessed 1 Oct 2017
Cross AJ, Major JM, Sinha R (2011) Urinary biomarkers of meat consumption. Cancer Epidemiol Biomark Prev 20:1107–1111. https://doi.org/10.1158/1055-9965.EPI-11-0048
Lykken GI, Jacob RA, Munoz JM, Sandstead HH (1980) A mathematical model of creatine metabolism in normal males–comparison between theory and experiment. Am J Clin Nutr 33:2674–2685
Shim J-S, Oh K, Kim HC (2014) Dietary assessment methods in epidemiologic studies. Epidemiol Health 36:e2014009. https://doi.org/10.4178/epih/e2014009
Knudsen N, Christiansen E, Brandt-Christensen M, Nygaard B, Perrild H (2000) Age-and sex-adjusted iodineacreatinine ratio. A new standard in epidemiological surveys? Evaluation of three different estimates of iodine excretion based on casual urine samples and comparison to 24 h values. Eur J Clin Nutr 54:361–363
Willett W (2012) Nutritional epidemiology, Third edit. Oxford University Press, Oxford; New York
EUthyroid project: This project has received funding from the European Union´s Horizon 2020 research and innovation programme under Grant agreement no. 634453.
ALSPAC: We are extremely grateful to all the families who took part in this study, the midwives for their help in recruiting them, and the whole ALSPAC team, which includes interviewers, computer and laboratory technicians, clerical workers, research scientists, volunteers, managers, receptionists and nurses. The UK Medical Research Council and Wellcome (Grant ref.: 102215/2/13/2) and the University of Bristol provide core support for ALSPAC. This publication is the work of the authors and Dr Bath will serve as a guarantor for the contents of this paper. ALSPAC data collection is funded from a wide range of sources, a comprehensive list of which is available on the ALSPAC website (http://www.bristol.ac.uk/alspac/external/documents/grant-acknowledgements.pdf). The existing iodine measurements in ALSPAC were funded from (1) the NUTRIMENTHE project, which received a research grant from the European Community’s 7th Framework Programme (FP7/2008–2013) under grant agreement 212652 and (2) a Ph.D. studentship that was funded by Wassen International and the Waterloo Foundation (2009–2012). We would like to thank Dr Pauline Emmett for helping with the dietary analysis of the ALSPAC food-frequency questionnaire.
Generation R: The Generation R Study is conducted by the Erasmus Medical Center in close collaboration with the Faculty of Social Sciences of the Erasmus University Rotterdam, the Municipal Health Service Rotterdam area, Rotterdam, and the Stichting Trombosedienst & Artsenlaboratorium Rijnmond (STAR-MDC), Rotterdam. The Generation R Study is supported by the Erasmus Medical Center, Rotterdam, the Erasmus University Rotterdam, The Netherlands Organization for Health Research and Development (ZonMw), The Netherlands Organization for Scientific Research (NWO), the Ministry of Health, Welfare and Sport. A grant from the Sophia Children’s Hospital Research Funds supports the neurodevelopmental work on thyroid; Robin P. Peeters is supported by a clinical fellowship from ZonMw, project number 90700412.
INMA: This study was funded by grants from UE (FP7-ENV-2011 cod 282957 and HEALTH.2010.2.4.5-1) and Spain: Instituto de Salud Carlos III (Red INMA G03/176; CB06/02/0041; FIS-FEDER: PI041436, PI05/1079, PI06/0867, PI081151, FIS-and PS09/00090, PI11/01007, PI11/02591, PI11/02038, PI13/1944, PI13/2032, PI14/00891, PI14/01687, and PI16/1288; Miguel Servet-FEDER CP11/00178, CP15/00025, and CPII16/00051, MS13/00054), Generalitat Valenciana: FISABIO (UGP 15-230, UGP-15-244, and UGP-15-249), Generalitat de Catalunya-CIRIT 1999SGR 00241, Fundació La marató de TV3 (090430), Department of Health of the Basque Government (2005111093 and 2009111069), and the Provincial Government of Gipuzkoa (DFG06/004 and DFG08/001).
Conflict of interest
The authors declare that they have no conflict of interest.
All studies in these analyses have been approved by the appropriate ethics committees and have, therefore, been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. Detailed information is included as part of the main text (see “Methods”, sub-section “Ethics”).
Electronic supplementary material
Below is the link to the electronic supplementary material.
About this article
Cite this article
Dineva, M., Rayman, M.P., Levie, D. et al. Similarities and differences of dietary and other determinants of iodine status in pregnant women from three European birth cohorts. Eur J Nutr 59, 371–387 (2020). https://doi.org/10.1007/s00394-019-01913-w
- Milk and dairy products