Iodine intake and status of UK women of childbearing age recruited at the University of Surrey in the winter

Br J Nutr. 2014 Nov 28;112(10):1715-23. doi: 10.1017/S0007114514002797. Epub 2014 Oct 2.


As intra-thyroidal iodine stores should be maximised before conception to facilitate the increased thyroid hormone production during pregnancy, women who are planning to become pregnant should ideally consume 150 μg iodine/d (US RDA). As few UK data exist for this population group, a cross-sectional study was carried out at the University of Surrey to assess the iodine intake and status of women of childbearing age. Total iodine excretion was measured from 24 h urine samples in fifty-seven women; iodine intake was estimated by assuming that 90 % of ingested iodine was excreted. The average iodine intake was also estimated from 48 h food diaries that the participants completed. The median urinary iodine concentration value (63·1 μg/l) indicated the group to be mildly iodine deficient by WHO criteria. By contrast, the median 24 h urinary iodine excretion value (149·8 μg/24 h) indicated a relatively low risk of iodine deficiency. The median estimated iodine intake, extrapolated from urinary excretion, was 167 μg/d, whereas it was lower, at 123 μg/d, when estimated from the 48 h food diaries. Iodine intake estimated from the food diaries and 24 h urinary iodine excretion were strongly correlated (r 0·75, P< 0·001). The intake of milk, eggs and dairy products was positively associated with iodine status. The iodine status of this UK cohort is probably a best-case scenario as the women were mostly nutrition students and were recruited in the winter when milk-iodine content is at its highest; further study in more representative cohorts of UK women is required. The present study highlights the need for revised cut-off values for iodine deficiency that are method- and age group-specific.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cross-Sectional Studies
  • Dairy Products
  • Deficiency Diseases / prevention & control
  • Deficiency Diseases / urine
  • Diet Records
  • Eggs
  • Energy Intake
  • Female
  • Humans
  • Iodine / administration & dosage*
  • Iodine / deficiency
  • Iodine / urine
  • Middle Aged
  • Nutritional Requirements*
  • Nutritional Status*
  • Pregnancy
  • Pregnancy Complications / prevention & control
  • Pregnancy Complications / urine
  • Reference Values
  • Seasons
  • United Kingdom
  • Young Adult


  • Iodine