Plant-based Alternatives to Dairy ‘Could Lead to Deficiencies in Nutrition’, Study Shows

Published on: 7 Nov, 2026
Updated on: 7 Nov, 2026

Replacing dairy products, even partially, with unfortified plant-based alternatives may lead to a deficiency in vital nutrients, a new study from the University of Surrey reports.

The researchers believe the findings are important for vegans and others following a plant-based diet.

But they have an answer. They conclude that mandatory fortification of plant-based alternatives and other foods, including bread, could lessen the risk of deficiencies, particularly iodine deficiency.

The study is said to be the first of its kind in the UK, involving researchers from Surrey and Queen’s University Belfast

Using data from the National Diet and Nutrition Survey, the study looked at 3,500 people aged between 18 months and 100 years old. The team assessed the impact of replacing dairy products with plant-based alternatives on four essential micronutrients found in dairy products – iodine, calcium, riboflavin and vitamin B12.

Dr Katie Nicol, co-author of the study and a Research Fellow at the University of Surrey, said: “With the rise in plant-based alternative foods, we need to know whether they are like-for-like replacements for the micronutrients that are found in dairy products. This is particularly important for vulnerable groups, including young children and adolescent females, who are more likely to be deficient in certain micronutrients, which could affect their overall health.”

The team found that even modest replacements of dairy intake with plant-based dairy alternatives led to marked declines in all four micronutrients, with iodine in particular being the most sensitive to replacements.

Dr Sarah Bath, Associate Professor at the University of Surrey and lead author, said: “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.

“People may be unaware of the importance of iodine, which is needed to make thyroid hormones to regulate our metabolism, and support healthy growth and brain development. Iodine is particularly important during pregnancy, when the requirement increases, but it is also essential prior to pregnancy to ensure that stores are optimised.

“People are unaware that dairy products are a major source of iodine and that plant-based alternatives, unless fortified, have a very low iodine content.”

The results suggest that the most effective strategy in reducing iodine inadequacy is to combine mandatory fortification of plant-based dairy alternatives with iodine-fortified bread.

Explaining the study’s method, Dr Anne Nugent from the School of Biological Sciences at Queen’s University Belfast said: “During the analysis, we first identified all foods and recipes containing dairy produce (milk, cheese and yogurt) in the national food survey for the UK, the National Diet and Nutrition Survey.

“Next, we conducted a series of replacement scenarios whereby we substituted the dairy present with an equal weight of plant based dairy alternatives. As the nutrient composition of dairy alternatives available on our supermarket shelves can vary, we also applied a condition to make sure that every dairy alternative we had identified in our previous market survey had an equal chance of selection.

“The last step was to examine the impact on dietary intakes of key nutrients following either the reduction or removal of dairy from the diet, replacing it with the dairy alternatives as above, and asking whether a series of fortification options could mitigate against any shortfalls in intake while avoid situations of excess.”

This study was published in Lancet Planetary Health.