Concerns about the environmental impact of animal-source foods have led to a shift towards plant-based alternatives (PBA). While dairy products and seafood are rich in iodine, an essential nutrient for thyroid function and cognitive development, PBA often lack iodine fortification. As the market expands, there is increasing concern that individuals replacing dairy products and seafood with unfortified PBA may be at risk of iodine deficiency. This study assessed changes in the iodine fortification of plant-based milk, yogurt, cheese and seafood alternatives through a cross-sectional survey of UK supermarkets (2020-2024). Supermarkets were surveyed online each December, and product nutrition and ingredient data were extracted. Between 2020 and 2024, the number of PBA increased by 55 %, with 466 PBA identified in 2024, including milk (n 246), yogurt (n 81), cheese (n 110) and seafood alternatives (n 29). Iodine fortification was inconsistent: in 2024, 48 % of non-organic milk alternatives were fortified, while only 5 % of non-organic yogurt and 4 % of cheese alternatives contained iodine. In comparison, 28 %, 6 % and 0 % of non-organic milk, yogurt and cheese alternatives were fortified with iodine in 2020. No fortified seafood alternatives were identified. Fortified PBA provided 75-83 % of the iodine content of cow's milk, but most remained poor iodine sources. Although iodine fortification has increased, it lags behind that of calcium and vitamin B12 (48 % v. 88 % and 71 %, respectively). Given iodine's critical role in health, clearer public health guidance and improved fortification policies are needed. Increased reliance on PBA may exacerbate iodine insufficiency in the UK without intervention.

Iodine deficiency is now a significant public-health concern in the UK. Data from the National Diet and Nutrition Survey (NDNS; 2019-2023) shows that several population groups are now classified as mildly iodine deficient, including women of childbearing age. This is a change from previous NDNS data where these groups were iodine sufficient. As iodine is needed for thyroid-hormone production, which are essential for brain development, iodine deficiency prior to, and during, pregnancy may have implications for child cognition - including lower IQ. However, the evidence base for the health effects of mild deficiency is not as strong as in severe deficiency. The WHO recommends salt iodisation to control iodine deficiency in a population, but such a policy was never introduced in the UK and iodised salt is not widely available. While UK milk is rich in iodine and is the principal source, the rise in popularity of plant-based milk alternatives may increase the risk of iodine deficiency. It may be necessary to give personalised advice to those with low iodine intake, but identify those at risk is challenging owing to a lack of a biomarker for iodine in an individual. Population-wide approaches may be required in the UK - for example, fortification of bread with iodised salt or mandatory iodine fortification of plant-based dairy alternatives. This review will critically discuss (i) the data on iodine deficiency in the UK (ii) the evidence base for the health implications of mild deficiency and (iii) the potential public-health solutions.

European iodine fortification programmes are heterogeneous and in some countries ineffective. A key problem with iodine nutrition is the low awareness of iodine deficiency-related risks common in the general population and among women of reproductive age. The major objective of EUthyroid2 is to improve the low awareness of IDD risks in adolescents and young women. The aim is to identify best practice models for accessing and disseminating information to increase awareness and improve iodine status, thereby establishing a foundation for young women to improve their own thyroid function, their general health and that of their offspring. To achieve this, EUthyroid2 will build on existing infrastructures and expertise established by the consortium during the initial EUthyroid project. All interventions tested will be tailored to specific regions and populations. EUthyroid2, by identifying the most effective intervention tools, will establish a solid foundation for paving the way for future national awareness campaigns.

Abstract Background Iodine deficiency remains a significant public health issue, further highlighted by the concern of its re-emergence in multiple countries. The health burden of iodine deficiency is high, especially in those who are vulnerable to the effects of iodine deficiency, such as pregnant women, infants, and children. Studies have shown that the public has low awareness and misconceptions regarding iodine. Increasing the understanding of the importance of iodine and its sources are crucial steps in controlling iodine deficiency in populations. This proposed systematic review aims to evaluate the effectiveness of education-based interventions and identify effective strategies that are associated with improved iodine knowledge, attitude, behaviour, and/or status, which could assist in improving iodine intake and combatting iodine deficiency. Methods This protocol follows the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) 2015 guidelines. The electronic databases that will be used to search for relevant studies are PubMed/MEDLINE, Web of Science, ScienceDirect, Scopus, and EMBASE, with no restriction on population and date. We will also explore Google Scholar to identify relevant studies. Two reviewers will perform the screening and data extraction, and disagreements will be solved by discussion or a third reviewer. We will synthesise the findings using meta-analyses where possible or otherwise via a narrative synthesis. Discussion The findings of the review will help to inform and guide the development and implementation of education programmes and evidence-based health interventions aimed at preventing iodine deficiency, with potential applicability to wider public health strategies. Systematic review registration PROSPERO CRD42025065136.

Mild-to-moderate iodine deficiency remains a public health challenge, particularly in Europe and in areas where access to iodine-rich foods or iodised salt is limited. Adolescents are a key target group for interventions, as early awareness can reduce the risk of iodine deficiency during future pregnancies. The EUthyroid2 project aims to raise iodine awareness among adolescents (aged 13–17y) to improve their iodine awareness and possibly iodine intake and indirectly enhance the health of them and their future children. A multi-country intervention study will be conducted in educational settings across six countries (Bangladesh, Pakistan, Slovenia, Cyprus, Germany and the UK). Data on iodine awareness, dietary habits, and socioeconomic status will be collected at baseline (T1), 2–4 weeks post-intervention (T2), and 26–34 weeks post-intervention (T3). A convergent parallel mixed-methods design will be employed for process evaluation. The intervention includes three components: teaching modules, an iodine feedback tool, and an online learning platform. The core content includes an iodine feedback tool and a lecture on iodine-related knowledge and awareness, accompanied by student exercises. A total of 4,500 students will be recruited. The main outcome of the study is the change in participants’ awareness and knowledge of iodine from baseline (T1) to follow-up points (T2 and T3). The intervention is expected to effectively improved understanding of iodine’s importance for health and promoted positive behavioural intentions related to iodine intake, while also providing an opportunity to enhance iodine nutrition beyond the scope of the current trial. This study contributes to evidence on effective health promotion approaches aimed at addressing iodine deficiency. Expanding such awareness interventions could lead to lasting improvements in public health by reducing the prevalence of iodine deficiency disorders, particularly among adolescents and future generations. ClinicalTrials.gov number NCT06769009. Registered 2025-01-08.

BACKGROUND:Low maternal urinary iodine concentration (UIC) during pregnancy is associated with adverse offspring neurodevelopment. Thyroglobulin (Tg) has been suggested as a more sensitive biomarker than UIC of long-term iodine status, but associations of Tg with neurodevelopment and the possible mediating role of thyroid function remain unknown. AIM:To study whether maternal Tg is associated with (1) maternal and newborn thyroid function and (2) offspring IQ and brain morphology. METHODS:Participants were selected from 2 population-based prospective cohorts: Generation R (the Netherlands, iodine-sufficient) and INfancia y Medio Ambiente (Spain, mildly iodine-deficient) with maternal Tg and thyroid function data in the first half of pregnancy or in cord blood, early childhood IQ (age 4.5 and 6 years), late childhood IQ (age 9 and 13), or brain morphology at 10 years. Associations of Tg with TSH, free T4 (FT4), IQ, and brain morphology were studied with multivariable linear regression. RESULTS:(1) Tg was associated with lower TSH (-0.12 [-0.16; -0.08]) and higher FT4 (0.08 [0.05; 0.12]) in pregnancy (n = 4367) but not with cord blood TSH or FT4 (n = 2008). (2) Tg was associated with lower IQ in early childhood (β [95% confidence interval]: -0.06 [-0.10; -0.01], n = 2919) but not with IQ (n = 2503) or brain morphology (n = 1180) in later childhood. None of the associations of Tg with the studied outcomes differed by the iodine-to-creatinine ratio (ie, effect modification) or changed when adjusted for thyroid function. CONCLUSION:Higher Tg is associated with lower IQ in early childhood and higher thyroid function during pregnancy but not with IQ or brain morphology in later childhood. Further research should determine the value of Tg in addition to UIC for defining iodine status.

Plant-based diets, with limited quantities of animal foods, are increasingly promoted for sustainability and health. In many countries, animal-source foods provide the majority of several micronutrients at a population level; in the UK, milk and dairy products contribute around one third of total calcium, vitamin B12 and iodine intake in adults. Recommendations for a predominantly plant-based diet may have the unintended consequence of reducing intake of micronutrients, particularly in groups with an already-low intake of these nutrients, such as women of reproductive age. Furthermore, young women are the group most likely to replace dairy products with plant-based alternatives. Milk alternatives are often fortified to match the nutrient content of cows' milk for some micronutrients (e.g. calcium), but not of others (e.g. iodine or vitamin B2). Unfortified alternatives have an iodine concentration that is just 2 % of that of UK cows' milk, and the rise in popularity of these products may increase iodine-deficiency risk in consumers. Low nutrient intake is of concern prior to, and during, pregnancy, when many of the micronutrients at risk (iron/calcium/iodine) are essential for foetal development. While there may be awareness of some at-risk nutrients on a plant-based diet, this may not be the case for all. At-risk nutrients should be considered in nutrition guidelines and advice given by healthcare professionals to ensure that the diets are well planned and supplemented when necessary. This review focuses on the provision of micronutrients (particularly iodine) from plant-based diets in the UK.

Current food systems pose risks to both population and environmental health. Reducing the intake of animal-based foods, such as dairy products, and increasing consumption of plant-based foods align with priorities for addressing climate change and promoting overall health. Plant-based alternatives to cow's milk can be readily substituted for cow's milk without altering meal patterns and food habits, making them a popular choice among those reducing animal-product consumption. However, plant-based milk alternatives do not necessarily provide the same nutrients as cow's milk, particularly essential micronutrients like iodine. While national data indicate that the UK is iodine-replete, certain population subgroups (such as pregnant women, women of reproductive age, and vegans) remain at risk of iodine deficiency. Young women are more likely than other age groups to consume plant-based milk alternatives, heightening public health concerns about iodine insufficiency in this demographic. Current consumers of plant-based milk alternatives in the UK have lower iodine intake and status compared to consumers of cow's milk. Population-level effects of replacing milk with plant-based alternatives vary and depend on factors such as the role of plant-based milk alternatives in the diet (i.e. in addition to, or as a replacement for milk), the presence of other iodine sources in the diet, the consumer's life stage, and whether the alternatives are fortified with iodine. This review examines the literature on plant-based milk alternatives and iodine intake, focusing on implications of this dietary shift and strategies to improve iodine intake in those opting for plant-based milk alternatives in the UK population.

The recommended intake of iodine during pregnancy is 250 µg/day (1). Iodine is a crucial micronutrient for offspring brain development, and previous research has shown that iodine deficiency can negatively influence offspring neurodevelopment (2,3). This analysis examines the relationship between maternal iodine intake during pregnancy and behavioural difficulties in children at 81 months (6.75 years). Women were from the Avon Longitudinal Study of Parents and Children (ALSPAC) who had singleton pregnancies and iodine intake data. Iodine intake was assessed at 32 weeks of gestation using a food frequency questionnaire (FFQ) (4) (n = 11,748). Behavioural difficulties at 81 months were assessed using the Strengths and Difficulties Questionnaire (SDQ), including prosocial, hyperactivity, emotional, conduct, peer and total difficulties. Linear and non-linear regressions were used to explore the relationships after adjusting for confounders based on previous literature and a directed acyclic graph (pre-pregnancy body mass index, intake of goitrogen-rich foods, alcohol intake, maternal and paternal education level, parity, age of mother at last menstrual period and energy intake). Likelihood ratio tests suggested that maternal iodine intake was non-linearly associated with peer (χ2(1) = 303.66, p = 4.95E-38) and total behavioural difficulties (χ2(1) = 178.61, p = 2.39E-16). Restricted cubic spline plots indicated there was an L-shaped relationship where iodine intake ≥150 µg/d was associated with lower behavioural scores (peer and total) (i.e. fewer behavioural difficulties) and intakes below 120 µg/g were associated with higher behavioural scores (i.e. more behavioural difficulties). Total behavioural scores steadily increased beyond intakes of 200 µg/d. Maternal iodine intake at 150-200 µg/d during pregnancy was associated with fewer peer and total behavioural difficulties in later childhood, reinforcing the importance of maintaining iodine intakes in pregnant women. However, excessive intake may have detrimental effects, in line with previous research in a Norwegian cohort (outcomes at 3 years old) (3). Future research should investigate the mechanisms underlying this association and consider how offspring iodine intake may moderate this association.

The EAT-Lancet Commission’s 2019 reference diet promotes health and environmental sustainability through predominantly plant-based foods, raising concerns about micronutrient adequacy, particularly iodine. This study evaluated the iodine content of the EAT-Lancet diet across sixteen countries using national food composition data. Iodine intake was modelled under three scenarios: (1) strict adherence to specified food items; (2) inclusion of a broader range of foods within each group; and (3) a vegan adaptation. In Scenario 1, dairy products, fish, and eggs were primary iodine sources, with intakes ranging from 42 µg/day (New Zealand) to 129 µg/day (United Kingdom), covering 28–85% of the adult requirements. Scenarios 2 and 3 showed higher iodine levels in countries using fortified bread, but most remained below adult and pregnancy requirements. These findings underscore the need to carefully evaluate iodine provision of plant-based dietary recommendations, particularly in countries without a fortification policy, to prevent iodine insufficiency.

PURPOSE:The Maharashtra Anaemia Study 3 (MAS 3) aims to (1) Investigate the nutritional, environmental, and economic impacts on haemoglobin concentration/anaemia, (2) Identify the underlying micronutrient causes of anaemia and (3) Investigate the association between anaemia and physical and cognitive development of Indian children during their first 18 years of life. This paper introduces the MAS 3 cohort, which consists of data collected from the participants in the prospective Pune Maternal Nutrition Study from the antenatal period to children at 18 years of age (1996-2014) in the Maharashtra state, India. PARTICIPANTS:Recruitment of 2466 married non-pregnant women, and their husbands, took place between June 1994 and April 1996 in six villages, approximately 50 km from Pune city in India. Women were followed up monthly to identify those who became pregnant. A total of 797 pregnant women were followed up for data collection at or near gestational week 18 and 28, with further data collection for women and children occurring within 72 hours of delivery, for both live and stillbirths. Of the 797 women, 710 were included in the MAS 3 cohort, and long-term follow-up of children occurred at 6 years, 12 years and 18 years of age. FINDINGS TO DATE:In the MAS 3 cohort, most mothers (73%) were aged between 18 and 25 years at the time of their final prepregnancy visit (baseline), and half (55%) belonged to families of middle-upper socioeconomic status (SES). At the children's baseline (birth) visit, children had a mean birth weight of 2630 g (SD: 376), with one third (31%) of low birth weight. At the 6-year, 12-year and 18-year follow-up visits, data were available for 706 (99%), 689 (97%) and 694 (98%) children. FUTURE PLANS:MAS 3 will be used to address a number of research objectives, including (1) Trends of haemoglobin and anaemia-related micronutrients from age 6 to 18 years, (2) Micronutrient causes of anaemia during childhood, (3) Prevalence and risk factors for maternal anaemia and childhood anaemia, (4) Impact of maternal anaemia on immediate birth outcomes and (5) Intergenerational risk factors associated with anaemia.

Iodine is an essential trace mineral and a key component of thyroid hormones, which are essential during pregnancy and infancy for brain and neurological development(1). The main dietary sources of iodine in the UK are seafood and dairy products, particularly milk(2). Recently, plant-based alternatives to seafood and dairy products have increased in popularity, particularly among young adults(3). Unless adequately fortified, these alternatives have a lower iodine content than their animal-based counterparts(4). This is a concern because consumers of plant-based alternatives are exposed to highly variable products and might be at risk of iodine deficiency. The number of alternative products on the market is rapidly expanding. Therefore, we aimed to investigate changes in the iodine fortification of plant-based alternatives to milk, yoghurt, cheese, and fish between 2020 and 2023.This study was a cross-sectional market survey of the eight leading UK supermarkets conducted in four annual waves (2020-2023) to evaluate the availability and composition of plant-based alternatives in the UK. The market was surveyed in December each year using online store data to search for plant-based products (milk, yoghurt, cheese, fish). Data was extracted from the product nutrition information and ingredient list.We found a 49% increase in plant-based products over the four years. During the 2023 wave, we identified 446 products, including plant-based milk (n 241), yoghurt (n 79), cheese (n 97) and fish alternatives (n 29). The number of products has grown in all categories since 2020, with the largest increase of 141% in plant-based fish alternatives. After excluding organic products, which cannot be fortified, only 35% (n 70) of milk alternatives, 6% (n 4) of yoghurt alternatives and 3% (n 3) of cheese alternatives were fortified with iodine in 2023, compared with 85% (n 169), 52% (n 46), and 55% (n 52), respectively, with calcium. Compared with 2020, there was no significant change in the proportion of milk, cheese or yoghurt alternatives fortified with iodine in 2023 (p>0.05). No fish alternatives were fortified with iodine. The range of iodine fortification of milk alternatives remained stable from 2020 to 2023 (11.3–45 μg/100mL), and the mean fortification all four years (25.4-27.4 μg/100mL) was lower than the average iodine concentration of conventional cow’s milk (30 μg/100mL)(5). Yoghurt and cheese alternatives were fortified at 22.5–45 μg/100g, similar to cow’s milk cheese and yoghurts.Our study highlights that most plant-based alternatives are not iodine-fortified and that using unfortified alternatives puts consumers at risk of iodine deficiency. Due to their increasing popularity, manufacturers of such alternative products should consider fortifying their products with an appropriate amount of iodine. Consistent and adequate fortification, accurate labelling and nutrition education are needed to help consumers make healthy and informed choices.

Iodine is a micronutrient that is essential for thyroid hormone production. Adequate iodine intake is especially important during pregnancy and early life, when brain development is dependent on thyroid hormones. Iodine intake recommendations vary around the world, but most recommendations generally reflect the increased requirements during pregnancy and lactation, although adequate iodine intake before pregnancy is also important. Tremendous progress has been made in improving iodine intake across the world over the past 30 years, mainly through salt-iodization programmes. However, in countries without strong iodine fortification programmes, and with shifts in dietary patterns, a need has arisen for health organizations, governments and clinicians to ensure that adequate iodine is consumed by everyone in the population. For example, in countries in which adequate iodine intake depends on individual food choice, particularly of iodine-rich milk and dairy products, intake can be highly variable and is also vulnerable to changing dietary patterns. In this Review, iodine is considered in the wider context of the increasing prevalence of overweight and obesity, the dietary trends for salt restriction for cardiovascular health and the increasing uptake of plant-based diets. This Review discusses the importance of adequate iodine intake for thyroid function, outlining the varying global intake recommendations. Iodine is also considered in the context of the increasing prevalence of overweight and obesity, as well as dietary trends such as cardioprotective salt restriction and plant-based diets. Despite progress since the 1990s, iodine deficiency remains a public health concern across the world, particularly in pregnancy and early life.Severe iodine deficiency is now less common than in the past, but mild-to-moderate deficiency during pregnancy might have consequences for the developing fetus, including on neurodevelopmental outcomes.Iodized salt programmes have been a successful way of improving iodine intake in many countries, but with a focus on salt-reduction campaigns, there is potential for reduced intake of iodized salt, and so reduced iodine intake, although both policies can work together.Animal foods, such as milk and dairy products, provide a considerable proportion of iodine intake in many countries, but with a shift towards a predominantly plant-based diet, iodine intake might be compromised unless consideration is given to ensure adequate iodine intake from suitable sources.

Iodine is essential for thyroid hormone production. Milk and dairy products are important sources of iodine in many countries. We aimed to review systematically the variation in milk‑iodine concentration between countries, seasons and farming practice. We searched online food composition tables and published literature for data since 2006. Milk‑iodine concentration was available for 34 countries (from 66 sources) and ranged from 5.5 to 49.9 μg/100 g (median 17.3 μg/100 g). Meta-analyses identified that iodine concentration is significantly higher in: (i) winter than summer milk (mean difference 5.97 μg/100 g; p = 0.001), and (ii) in conventional than in organic milk (mean difference 6.00 μg/100 g; p < 0.0001). Sub-group analysis showed that the difference between organic and conventional milk was only significant in summer (p = 0.0003). The seasonal variation in milk‑iodine concentration may affect iodine intake and status so should be considered in dietary surveys, and when assessing population iodine status.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Purpose Cow’s milk is the primary source of iodine in the UK, but consumption of plant-based milk alternatives (PBMA) is increasing and these products are often not fortified with iodine. We evaluated the impact that replacing current milk consumption with PBMA would have on iodine intake. Methods We used data from the National Diet and Nutrition Survey (2016–2019) for children (1.5–10 years), girls 11–18 years, and women of reproductive age (WRA). We used a dietary modelling approach with scenarios using brand-level iodine-fortification data (0, 13, 22.5, 27.4 and 45 µg/100 mL). Relative to usual diet, we calculated change in iodine intake, and the proportion with intake below the Lower Reference Nutrient Intake (LRNI) or above the upper limit. Results For all groups, replacement with PBMA, either unfortified or fortified at the lowest concentration, resulted in a meaningful decrease in iodine intake, and increased the proportion with intake < LRNI; compared to usual diet, iodine intake reduced by 58% in children 1.5–3 years (127 vs. 53 µg/day) and the proportion with intake < LRNI increased in girls (11–18 years; 20% to 48%) and WRA (13% to 33%) if an unfortified PBMA was used. Replacement of milk with PBMA fortified at 27.4 µg/100 mL had the lowest impact. Conclusion Replacing milk with commercially available PBMAs has potential to reduce population iodine intake, depending on the fortification level. PBMAs fortified with ≥ 22.5 and < 45 µg iodine/100 mL would be required to minimize the impact on iodine intake. Research is needed on the impact of total dairy replacement.

There is no salt iodisation policy in the UK, and the majority of iodine intake is from milk and dairy products(1). The availability of iodised table salt in the UK was last investigated in 2009, and was found to be low(2). As table salt contributes only approximately 15% to total salt intake, it is important to know whether any of the salt in processed foods is iodised. This study therefore aimed to update the availability of iodised table salt and review its use in processed foods that are available in the UK.Iodised table salt availability was investigated in ten supermarket chains (nine online and one instore), covering 96.6% of the market share(3). Data was collected on price per kilogram for iodised and own-brand table salt. A Google-site search of the supermarket wesbites was conducted between 28 February and 4 April 2024; both the terms “iodised” and “iodized” were searched to identify all processed foods containing iodised salt. Data on product name, ingredients, salt content per 100 g and per portion, and country of origin were extracted. Duplicate products and items no longer available were removed. Salt per portion was calculated using serving sizes on the product label or equivalent products, and estimated portion sizes were used if these were unavailable. Iodine per portion was then calculated by assuming that salt was iodised at a concentration of 20 mg/kg.Iodised table salt was available in three of the ten (30%) supermarkets (as one brand). Iodised salt was over four-times more expensive than own-brand table salt (£4.17/kg vs.£1.02/kg); the difference was smaller than in 2009 when it was six-times the price. The iodine concentration of the iodised table was 20 mg/kg, an increase from 2009 when it was 11.5 mg/kg(2).A total of 240 processed foods containing iodised salt were identified across all supermarkets. The country of origin was mostly unspecified (46.7%, n = 112) but where it was, most products were from Germany (19.6%, n = 47). The most common (35.4%, n = 85) food group containing iodised salt was meat products (including hot dogs, pâté, salami), followed by stock/sauce/spices/condiments (22.5%, n = 54) and pasta/noodle products (12.9%, n = 31). Average iodine per portion was 19.4 µg (range 0.44-94 µg), which would provide 13% (range 0.3-63%) of adult recommendations (150 µg/day).Iodised table salt is available at fewer supermarket chains than in 2009. Iodised salt is used in some processed foods available in the UK though the iodine content is not provided on the nutrition label. When estimating iodine intake in dietary assessments, the potential contribution from iodised salt in some processed foods should be considered. Salt intake, even if iodised, should not exceed recommendations.

Milk, dairy products, and fish are the main sources of iodine in the UK. Plant-based products are increasingly popular, especially with young women, which may affect iodine intake as they are naturally low in iodine; this is concerning as iodine is required for fetal brain development. We, aimed to (i) assess the iodine fortification of products sold as alternatives to milk, yoghurt, cheese and fish through a cross-sectional survey of UK retail outlets in 2020, and (ii) model the impact of substitution with such products on iodine intake, using portion-based scenarios. We identified 300 products, including plant-based alternatives to: (i) milk (n 146); (ii) yoghurt (n 76); (iii) cheese (n 67) and (iv) fish (n 11). After excluding organic products (n 48), which cannot be fortified, only 28 % (n 29) of milk alternatives and 6 % (n 4) of yoghurt alternatives were fortified with iodine, compared with 88 % (n 92) and 73 % (n 51), respectively, with Ca. No cheese alternative was fortified with iodine, but 55 % were fortified with Ca. None of the fish alternatives were iodine fortified. Substitution of three portions of dairy product (milk/yoghurt/cheese) per day with unfortified alternatives would reduce the iodine provided by 97·9 % (124 v. 2·6 µg) and substantially reduce the contribution to the adult intake recommendation (150 µg/d; 83 v. 1·8 %). Our study highlights that the majority of plant-based alternatives are not iodine fortified and that the use of unfortified alternatives put consumers at risk of iodine deficiency.