THERAPY OF ENDOCRINE DISEASE: Impact of iodine supplementation in mild-to-moderate iodine deficiency: systematic review and meta-analysis
Abstract
Background: Although the detrimental effects of severe iodine deficiency are well recognised, the benefits of correcting mild-to-moderate iodine deficiency are uncertain. Objectives: We undertook a systematic review of the impact of iodine supplementation in populations with mild-to-moderate iodine deficiency. Methods: We searched Medline and the Cochrane library for relevant articles published between January 1966 and April 2013, which investigated the effect of iodine supplementation on maternal and newborn thyroid function, infant neurodevelopment and cognitive performance in school-age children. The quality of studies was graded and eligible trials were evaluated in the meta-analysis. Results: Nine randomised controlled trials (RCTs) and eight observational studies met the inclusion criteria. Controlled trials on infant neurodevelopment were lacking; gestational iodine supplementation reduced maternal thyroid volume and serum thyroglobulin and in some studies prevented a rise in serum thyroid-stimulating hormone. None of the intervention trials recorded an excess frequency of thyroid dysfunction in contrast to observational studies. A pooled analysis of two RCTs which measured cognitive function in school-age children showed modest benefits of iodine supplementation on perceptual reasoning (standardised mean difference (SMD) 0.55; 95% CI 0.05, 1.04; P =0.03) and global cognitive index (SMD 0.27; 95% CI 0.10, 0.44; P =0.002) with significant heterogeneity between studies. Conclusion: Iodine supplementation improves some maternal thyroid indices and may benefit aspects of cognitive function in school-age children, even in marginally iodine-deficient areas. Further large prospective controlled studies are urgently required to clarify these findings and quantify the risk/benefits of iodine supplementation in regions previously believed to be iodine sufficient such as the UK.
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Severe, but not mild-to-moderate, iodine deficiency results in hypothyroidism.
“Severe, but not mild-to-moderate, iodine deficiency results in hypothyroidism.61”
From Hypothyroidism (2024) · cites this paper as [61]
A recent meta-analysis including nine randomized-controlled trials and eight observational studies involving iodine supplementation of young children and pregnant women in regions of mild to moderate iodine deficiency did not find an increased risk of thyroid dysfunction following iodine supplementation of 200-300 mg/d.
“a recent metaanalysis including nine randomized-controlled trials and eight observational studies involving iodine supplementation of young children and pregnant women in regions of mild to moderate iodine deficiency did not find an increased risk of thyroid dysfunction following iodine supplementation of 200-300 mg/d (571).”
From 2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis (2016) · cites this paper as [571]
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References 81 · Cited by 151
- Authors
- Taylor, P. N., Okosieme, O. E., Dayan, C. M., & Lazarus, J. H.
- Affiliations
- Cardiff University (GB)
- Corresponding author
- Taylor, Peter N
- Venue
- European Journal of Endocrinology
- Publisher
- Oxford University Press (OUP)
- Published
- 2014-01
- Volume
- 170
- Issue
- 1
- Pages
- R1-R15
- ISSN
- 0804-4643 (ISSN-L)
- 1479-683X
- OpenAlex
- W2164331551
- Cited by
- 151
- References
- 81
- Citations by year
- 2026: 7 · 2025: 5 · 2024: 5 · 2023: 3 · 2022: 13 · 2021: 16 · 2020: 12 · 2019: 9 · 2018: 17 · 2017: 15 · 2016: 15 · 2015: 18 · 2014: 15
- FWCI
- 2.35
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- European Journal of Endocrinology (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Thyroid Disorders and Treatments
- Health Sciences › Nursing › Nutrition and Dietetics › Child Nutrition and Water Access
- Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Thyroid Cancer Diagnosis and Treatment
- Keywords
- iodine supplementation, maternal thyroid function, serum thyroglobulin, thyroid-stimulating hormone, infant brain development, perceptual reasoning, thyroid dysfunction
- MeSH terms
- Adult, Child, Child Development, Cognition Disorders, Diet, Female, Humans, Infant, Iodine, Male, Perceptual Disorders, Pregnancy, Severity of Illness Index, Thyroid Gland, Sodium Chloride, Dietary, Evidence-Based Medicine, Dietary Supplements, Maternal Nutritional Physiological Phenomena, Fetal Development, Neurogenesis
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