Replacing dairy products with plant-based alternatives could lead to significant micronutrient deficiencies, particularly among young people and women, according to a new study published in Lancet Planetary Health. Researchers warn that even partial substitution of milk, cheese, and yoghurt with vegan options can cause dangerous drops in iodine, calcium, riboflavin, and vitamin B12 if the substitutes are not properly fortified.
Iodine Deficiency Risks for Young Women
The study highlights iodine as the primary concern. This trace element is essential for thyroid function, metabolism, and healthy brain development. In the UK, dairy products currently provide approximately half of the iodine intake for children and a third for adults. However, there is no legal requirement for plant-based alternatives to be fortified with this nutrient.

Modelling based on typical market levels of fortification shows that replacing just one-fifth to one-third of dairy intake with plant-based options would raise the prevalence of iodine deficiency among adolescent girls from 54% to 65%. For women aged 19 to 49, the rate would rise from 32% to 42%. If consumers switched entirely to non-dairy alternatives, inadequate iodine levels would reach 80% in teenage girls and 72% in teenage boys.
Dr Sarah Bath, an associate professor in public health nutrition at the University of Surrey, emphasized the urgency of the issue. She noted that young women and those of childbearing age have the lowest intakes and are at the highest risk. Iodine is particularly critical during these life stages for supporting healthy growth and development.
Fortification Gaps in the Market
The researchers analyzed 146 non-dairy milks, 76 yoghurts, and 67 cheeses available on the UK market. While 61% of these products had added calcium and 46% included vitamin B12, only 19% were fortified with riboflavin. A mere 12% contained added iodine. This lack of fortification means that swapping a third of dairy intake for vegan alternatives leads to a 9% to 21% drop in iodine intake, with other nutrients also falling.

The study suggests that mandatory fortification could solve the problem. Requiring all non-dairy alternatives to be fortified with iodine would prevent average declines in intake. The model also showed that adding iodised salt to bread helped reduce the proportion of teenage girls with inadequate iodine levels in the simulated scenarios.
Some companies are already addressing these gaps. Niamh Brannelly, head of nutrition and science communications for Danone in the UK, stated that their core Alpro range is fortified with calcium, iodine, and vitamins B2 and B12. Caroline Orfila Jenkins, vice-president for science and technology at Oatly, confirmed that all their unflavoured, non-organic oat drinks are fortified with iodine, calcium, riboflavin, and vitamins B12 and D.

Nichola Ludlam-Raine, a registered dietitian and spokesperson for the British Dietetic Association, advised consumers to check labels carefully. She recommended choosing plant-based milks fortified with iodine and noted that organic drinks are unlikely to provide added nutrients. She also suggested that white fish, eggs, and dairy products like kefir can contribute to iodine intake, while warning against relying on seaweed supplements due to inconsistent iodine levels.
Source: The Guardian

