Named the risk of switching from dairy products to plant substitutes

The study found that switching from dairy products to plant-based alternatives could lead to deficiencies in vital micronutrients, especially among young people and women.

Scientists say that even a partial switch to vegan alternatives to milk, cheese and yogurt can lead to lower levels of iodine, calcium, riboflavin and vitamin B12 if substitutes, often based on soy, almonds or oats, are not fortified with vitamins.

The greatest concern is iodine - a trace element that is used by the thyroid gland to produce hormones that regulate metabolism and support healthy brain growth and development. According to researchers, more than half of teenage girls in the UK are already getting insufficient amounts of iodine.

According to modelling based on typical market fortification levels, replacing a fifth to a third of dairy products consumed with plant-based alternatives would increase the prevalence of iodine deficiency from 54% to 65% among adolescent girls and from 32% to 42% among women aged 19 to 49 years.

“The health effects of iodine deficiency are known, and that’s why we want to raise awareness about this,” said Dr. Sarah Bath, assistant professor of nutrition at the University of Surrey. The populations that appear to be at risk and getting the least iodine are young women and women of childbearing age, a key stage in life when iodine is particularly important.

Plant-based alternatives to milk, cheese and yogurt are on the rise, although there are signs that some consumers are abandoning them.

In Britain, children get about half of the total iodine intake and adults about a third of the total iodine intake from dairy products, but there is no official requirement that vegan alternatives be fortified with micronutrients.

The researchers examined the impact of dairy substitution on plant-based alternatives in the UK market, including 146 types of non-dairy milk, 76 yogurts and 67 cheeses. While 61% of them added calcium and 46% vitamin B12, only 19% were fortified with riboflavin and 12% with iodine.

Modeling showed that replacing a third of dairy products with vegan alternatives led to a 9-21% reduction in iodine intake, as well as calcium, riboflavin and vitamin B12. The switch to 100% non-dairy products has led to insufficient iodine levels reaching 80% in adolescent girls and 72% in adolescent boys.

The study found that requiring all non-dairy products to be fortified with iodine would have prevented the average decline. Adding iodized salt to bread has helped reduce the proportion of teenage girls getting insufficient iodine in their diet. The study was published in The Lancet Planetary Health.

Some companies are already enriching their dairy substitutes.

Nicola Ludlam-Rhine, a registered dietitian and spokesperson for the British Dietetic Association, said the work raised serious concerns at the population level, but did not mean that everyone who switched to a different diet would develop nutritional deficiencies, as overall diet also mattered. For anyone who prefers plant-based milk, I would recommend checking the label and choosing iodine-fortified milk. “Organic drinks are not fortified with additional nutrients, so they are unlikely to contain iodine.” White fish such as cod or haddock, as well as eggs, yogurt and kefir for those who consume them, also contain iodine. I would not recommend using seaweed or kelp as a source of iodine, as the iodine content can vary greatly and be excessive