A recent analysis published in Lancet Planetary Health has found that replacing dairy products with plant‑based alternatives such as oat, almond or soy milk, fortified yogurts and cheese could leave many people, particularly children, teenagers and women, deficient in essential micronutrients like iodine, calcium, vitamin B12 and riboflavin.
Who Is Most at Risk?
The research identified children, adolescents and women of reproductive age as the groups most likely to suffer adverse health effects from reduced dairy consumption. Girls aged 14‑18 and boys of the same age showed the steepest rises in inadequate iodine intake when even a modest portion of dairy was swapped for plant‑based options.
Nutrient Gaps in Plant‑Based Alternatives
The investigation examined 146 plant‑based milks, 76 yogurts and 67 cheese products, measuring how often each was fortified with iodine, calcium, vitamin B12 or riboflavin. Only 12 % of the items contained added iodine, while 61 % were fortified with calcium, 46 % with vitamin B12 and 19 % with riboflavin. Modelling showed that replacing 20‑35 % of dairy with unfortified plant‑based foods increased iodine deficiency among girls aged 14‑18 from 54 % to 65 % and among women 19‑49 from 32 % to 42 %; full substitution pushed teenage girls’ inadequate iodine intake to 80 % and boys to 72 %. Calcium inadequacy rose from 30 % to 47 % in boys and from 54 % to 70 % in girls when all dairy was removed. For riboflavin, men aged 19‑49 saw inadequate intake climb from 14 % to 26 %, while women’s figures jumped from 29 % to 50 % with complete dairy replacement, and a 39 % rise was observed when only half of dairy was swapped.
Policy Implications and Fortification
The authors argue that mandatory fortification of plant‑based foods, including the introduction of iodine‑enriched bread, could close the nutrient gaps identified in the study. They stress that while moderate reductions in dairy are unlikely to harm most people, those already consuming low levels of calcium, iodine or riboflavin may face further shortfalls. Dr Sarah Bath, lead author and associate professor at the University of Surrey, warned that “the UK is particularly vulnerable to iodine insufficiency due to a lack of an iodine fortification policy such as universal salt iodisation, which many other countries have.”
Expert Perspectives
Dr Katie Nicol, co‑author and research fellow at the University of Surrey, added that “nutrition policy must evolve in tandem with environmental targets however it is important that shifts towards more sustainable diets do not compromise on public health.” Professor Mairead Kiely of the Cork Centre for Vitamin D and Nutrition Research noted that “plant‑based dairy alternatives , unless fortified appropriately, do not contain equivalent amounts of calcium, iodine, riboflavin and vitamin B12 as milk, yoghurt and cheese.” Dr Janette Walton, lead investigator for national dietary surveys in Ireland, cautioned that “with dietary guidelines now recommending a large shift from animal‑based diets to more plant‑based diets in response to meeting global sustainability goals, unintended consequences for the health of teenage girls and young women must be considered.” Tom Sanders, Professor emeritus of nutrition and dietetics at King’s College London, highlighted a limitation of the study, stating that “iodine deficiency cannot be reliably predicted from dietary intake records because the iodine content is dependent on the amount in the soil in which plant foods are grown”. Emily Angus, senior dietitian at The Vegan Society, clarified that “the majority of plant‑based milk alternatives available to UK consumers are fortified with calcium and vitamin D as a minimum,” and urged consumers to choose fortified products in line with the 2025 SACN guidance.
Why it Matters
The findings underscore a critical public health dilemma: as the UK moves toward more sustainable, plant‑based diets to meet climate goals, vulnerable populations risk losing key nutrients that support thyroid function, bone health, and neurological development. Without targeted fortification policies, the unintended health consequences of reduced dairy intake could undermine both individual wellbeing and broader NHS objectives around bone strength and metabolic regulation.