Variation in the iodine content of milk, dairy products, and eggs and the implication for UK iodine intake; studies at the farm, retail, and populatio

碘缺乏在英国的一些人群中很常见，比如育龄妇女。这是一个公共卫生问题，因为在怀孕期间即使是轻度到中度的缺乏也会导致儿童智商较低。在英国和许多国家，牛奶、乳制品和鸡蛋是碘的主要膳食来源，它们占英国成年人碘总摄入量的40%以上，儿童碘摄入量高达68%（国家饮食与营养调查数据，2021年）。我们知道牛奶中的碘浓度有很大的变化——例如，碘浓度随季节而变化，夏季牛奶中的碘含量较低。牛饲料的成分，例如白三叶草，可能起到致甲状腺肿的作用，减少碘向牛奶的转移，尽管缺乏数据来证实这种作用。虽然已知农业做法与牛奶中碘含量之间存在相互作用，但没有数据表明其对其他乳制品（如酸奶）或鸡蛋中碘含量的影响。估算牛奶、奶制品和鸡蛋的最佳碘浓度是确保人群摄入足够碘的关键。这一点在英国尤其正确，因为英国没有在食盐中添加碘的政策，而在其他许多国家，碘盐是碘的重要来源。

Iodine deficiency is common in some UK groups, such as in women of childbearing age. This is a public-health concern as even mild-to-moderate deficiency during pregnancy is associated with lower IQ in children. In the UK, and many countries, milk, dairy products, and eggs are the main dietary sources of iodine, together contributing over 40% of total iodine intake in UK adults, and up to 68% in children (National Diet & Nutrition Survey data, 2021).We know that there is considerable variation in the iodine concentration in milk - for example iodine concentration varies by season, with lower iodine in summer milk. Components of cattle feed, for example white clover, may act as goitrogens and reduce the transfer of iodine into milk, although data are lacking to confirm this effect. While there is a known interaction between agricultural practice and the iodine content of milk, there are no data on its effects on the iodine content of other dairy products (e.g. yoghurt) or eggs.Estimating the optimum iodine concentration of milk, dairy products, and eggs is key to ensuring adequate iodine intake in the population. This is especially true in the UK as there is no policy to fortify salt with iodine, unlike in many other countries where iodised salt is an important source of iodine.