UK modelling study links replacing dairy with plant-based alternatives to lower iodine intake

A modelling study published in The Lancet Planetary Health found that replacing milk, cheese and yoghurt with plant-based alternatives at current market fortification levels reduced intake of four micronutrients: iodine, calcium, riboflavin and vitamin B12.

Iodine was the main concern. The Guardian called it the greatest concern, while Medical Xpress said it was the most sensitive to replacement.

Before any modelled replacement, 54% of adolescent girls and 32% of women aged 19 to 49 had inadequate iodine intake. Under partial replacement, those figures rose to 65% and 42%. The Guardian describes this level as a fifth to a third of dairy intake; Medical Xpress describes it as 20% to 35%. Under full replacement, inadequate intake reached 80% among adolescent girls and 72% among adolescent boys.

The study found that mandatory fortification of plant-based alternatives would prevent declines in intake; the Guardian specifies average declines in iodine intake. Adding iodine to bread also reduced the proportion of adolescent girls with inadequate intake in the modelled scenarios.

According to Medical Xpress, iodine intake remained inadequate in 59% of adolescent females with mandatory fortification, and iodine-fortified bread reduced that figure to 37%. Medical Xpress reported that the results suggest combining the two measures is the most effective strategy.

According to Medical Xpress, the University of Surrey led the research with Queen's University Belfast. The modelling used national diet survey data from more than 3,500 people aged 18 months to 100 years.

According to the Guardian, 12% of the UK plant-based products examined had added iodine, and 61% had added calcium. The Guardian also reported that there is no formal UK requirement to fortify vegan alternatives.

What each side says

• Dr Sarah Bath of the University of Surrey, the lead author according to Medical Xpress, said young women and women of childbearing age appear to be at risk. She also said the UK lacks an iodine fortification policy such as universal salt iodization.
• Dr Katie Nicol, a University of Surrey co-author, said government policy is needed for fortification to happen, according to Medical Xpress.
• Niamh Brannelly of Danone UK said the core Alpro range is fortified with calcium, iodine and vitamins B2 and B12, according to the Guardian.
• The Guardian quoted Caroline Orfila Jenkins of Oatly as saying: "This research underlines the importance of appropriate fortification as diets become more plant-based".
• Nichola Ludlam-Raine, a British Dietetic Association spokesperson, said the work raises a population-level concern but does not mean everyone who switches will become deficient, according to the Guardian.

What is not known

The figures are modelled intakes from one study. The reports reviewed by Vocemundi do not describe measured health outcomes in people who switched. They also do not include a UK government or regulator response, or a separate replication.

Analysis

The findings could inform UK debate on food fortification, although the reports do not include a response from government or regulators. Mandatory fortification and iodine-fortified bread appear in the modelling as possible ways to limit inadequate intake. Whether either is adopted would depend on policy decisions the reports do not address. Consumer habits may also matter, as the Guardian reports signs that some people are shifting back from plant-based products. The results come from one modelling study, so measured iodine status in people who switch and independent replication would help show how closely these estimates reflect real-world diets.

Produced by the Vocemundi newsroom with AI assistance.