Replacing dairy foods with plant-based alternatives may bring an overlooked nutritional trade-off when those substitutes are not fortified, according to a new UK study. Researchers found that even partial replacement of milk, yogurt and cheese with commercially available plant alternatives could reduce intake of several micronutrients that dairy products commonly provide.
The study, led by researchers at the University of Surrey in collaboration with Queen’s University Belfast, examined iodine, calcium, riboflavin and vitamin B12. It was published in Lancet Planetary Health. Its authors say the findings strengthen the case for considering mandatory fortification of plant-based alternatives and other foods, including bread, particularly to reduce the risk of iodine inadequacy.
Modeling a changing diet
Plant-based eating is increasingly prominent in discussions of environmental sustainability and dietary change. At the same time, plant-based alternatives to dairy are now widely available. The question addressed by the research is not whether people should or should not choose those products, but whether commercially available alternatives currently provide equivalent micronutrients when they replace dairy foods.
The researchers used data from the UK National Diet and Nutrition Survey covering more than 3,500 people aged from 18 months to 100 years. They then applied a modeling approach to assess the nutritional effect of replacing milk, yogurt and cheese with plant-based alternatives available on the market.
The four nutrients studied are all found in dairy products: iodine, calcium, riboflavin and vitamin B12. The analysis found marked declines in intake of all four when dairy was replaced under current levels of market fortification. Iodine was particularly sensitive to the change.
Iodine emerged as the sharpest concern
According to the researchers, replacing 20% to 35% of dairy products with plant-based alternatives increased iodine inadequacy among adolescents under present market fortification levels. That finding is significant because a modest replacement is different from a fully dairy-free diet: the nutritional effect appeared even when dairy was only partly displaced.
The study’s results should not be read as a claim that all plant-based products have the same nutritional profile. Fortification varies between products, and the researchers specifically focus on the risk posed by unfortified alternatives. Their conclusion is instead that consumers cannot assume a plant-based drink, yogurt or cheese alternative is a like-for-like micronutrient replacement for its dairy counterpart.
Dr. Katie Nicol, a University of Surrey research fellow and co-author, said this comparison is important as dietary recommendations increasingly emphasize plant-based patterns and reduced intake of animal products. The nutrient question is particularly important, she noted, for groups including young children and adolescent females, who may be more likely to be deficient in certain micronutrients.
Fortification is the policy question
Fortification is already a familiar public-health approach: nutrients are added to foods to help prevent shortfalls in a population. In this study, the authors argue that mandatory fortification of plant-based alternatives and other foods could lessen deficiency risks. Iodine is singled out as a particular concern.
That proposal shifts some of the burden away from individuals having to navigate a variable marketplace product by product. A consumer can read labels and choose fortified options, but labels do not automatically make the nutritional comparison simple, especially when several nutrients are involved and diets differ by age and eating pattern. A more consistent fortification framework could make substitutions less risky at a population level.
It also raises practical questions for regulators and food companies. Any requirement would need to determine which products are covered, which nutrients and levels are appropriate, and how to account for different dietary needs. The study itself does not settle those implementation choices. It does provide evidence that the existing market mix may not reliably preserve the micronutrient contribution of the dairy foods being replaced.
Dietary shifts need nutritional equivalence
The research arrives amid a broader effort to align food systems with environmental goals. Plant-based diets and reduced animal-product consumption are often considered in that context. The Surrey-led analysis adds a necessary qualification: changing the source of a food is not automatically the same as replacing its nutrient contribution.
For households using plant alternatives, the immediate takeaway is not that such products must be avoided. Rather, the study points to a need for attention to fortification and overall dietary adequacy, particularly when milk, yogurt and cheese are being replaced regularly. The findings also support more precise dietary guidance that distinguishes between fortified and unfortified alternatives.
At the policy level, the authors’ case is direct. If plant-based foods are expected to play a larger role in diets, their micronutrient profile needs to be considered alongside their environmental role. The transition away from dairy can be judged by more than calories, taste or carbon impact; it also has to be judged by whether essential nutrients remain available to the people making that transition.
This article is based on reporting by Medical Xpress. Read the original article.
Originally published on medicalxpress.com
