Iodine And Selenium Nutrition In Women Of Reproductive Age

  • Claire Boakes

Student thesis: Doctoral Thesis


Adequate nutritional status is fundamental for optimal foetal development both before conception and during pregnancy. Women are advised to improve their dietary habits and build up stores of nutrients in preparation for pregnancy, however up to 50% of pregnancies in the UK are thought to be unplanned. Recommendations and advice on supplements and healthy eating are provided by health professionals but this is delivered inconsistently and may be too late to make a difference in early pregnancy when most organogenesis takes place. Iodine and selenium are micronutrients which are vital for synthesis of maternal thyroid hormones. These are essential for brain development in the growing foetus, and the foetus is entirely dependent on the maternal supply of thyroid hormones in the first trimester. Mild maternal deficiency of iodine in utero has been implicated in reduced cognitive functioning in infants and children. Recent studies have emphasised the prevalence of iodine deficiency in the UK, but these have been mainly been focussed on women already expecting a baby. This study aimed to investigate iodine status in a population of women of reproductive age, who may become pregnant in the medium to short term. Particular attention was given to younger women (aged 16-19 years) who are statistically more at risk of an unplanned pregnancy; there has so far been no work done in relation to iodine nutrition in this age group. The results of this study suggest a major concern for maternal nutritional health. Urinary excretion of iodine from spot urine samples indicative of mild deficiency was found in women of reproductive age in all age ranges. In the second part of the study, 24-hour urine samples showed most participants classified as having either mild or moderate iodine deficiency. Urinary selenium concentrations were also low for most participants. Dietary intakes of nutrients essential for a healthy pregnancy were generally low, predominantly in younger women. In addition, younger women with an expected prior knowledge of good nutrition were unable to correctly identify food sources of iodine or the effects of iodine deficiency. They were also unable to correctly answer to questions about other important nutrients such as folic acid. Initiatives to educate women of reproductive age, especially those aged 16-19 years, about the importance of iodine nutrition and the possible influence of selenium, along with other pregnancy related nutrients, should be considered as part of a public health strategy to address iodine deficiency.
Date of Award28 Apr 2023
Original languageEnglish
SupervisorJane Owen-Lynch (Main Supervisor) & Deborah Pufal (Main Supervisor)

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