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.

中文翻译：

---

碘对哺乳期妇女和婴儿甲状腺功能的作用。


碘是产生甲状腺激素所需的微量营养素，甲状腺激素调节新陈代谢、生长和发育。碘缺乏或过量可能会改变甲状腺激素的合成。对婴儿发育的潜在影响取决于接触的程度、时间和持续时间。由于甲状腺激素周转率升高，婴儿期的碘需求特别高。母乳喂养的婴儿依赖母乳提供碘，但母乳中的碘浓度是由母亲的碘摄入量决定的。许多国家的饮食无法提供足够的碘，通过盐中的碘强化可以防止碘缺乏。然而，不同国家的碘盐覆盖率有所不同。流行病学数据表明，全世界哺乳期妇女、婴儿和幼儿的碘摄入量存在很大差异，从摄入不足到摄入过量。在这篇综述中，我们概述了对碘营养及其与哺乳期妇女、婴儿和幼儿甲状腺功能的关系的了解的当前知识和最新进展。我们讨论了碘营养不良的危险因素以及有针对性的干预策略对这些弱势群体的影响。我们强调适当定义最佳碘营养的重要性，以及需要更多数据来评估生命前两年轻度碘缺乏导致甲状腺疾病的风险。