Plant-Based Milk Switch May Cause Micronutrient Deficiencies 2026

Switching from dairy to plant-based milk, cheese, and yoghurt could lead to deficiencies in vital micronutrients, especially among young people and women, a new study has found. Even partial moves to vegan alternatives may reduce intake of iodine, calcium, riboflavin, and vitamin B12 if the substitutes are not fortified, scientists warn.

The research, led by Dr Sarah Bath, an associate professor in public health nutrition at the University of Surrey, highlights concerns about iodine—a trace element essential for thyroid function, metabolism, and brain development. More than half of UK teenage girls already have inadequate iodine intake, and the study suggests that replacing just a fifth to a third of dairy with plant-based alternatives could worsen this.

Why Iodine Is a Critical Nutrient

Iodine is used by the thyroid gland to produce hormones that regulate metabolism and support healthy growth and brain development. Deficiency is particularly dangerous during pregnancy and childhood, when it can impair cognitive development. The study notes that adolescent girls and women of childbearing age are most at risk because they often have the lowest iodine intakes.

According to the modelling, replacing 20-33% of dairy intake 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 19-49. These figures are based on typical market levels of fortification, meaning many products are not adequately fortified.

Other Micronutrients at Risk

Besides iodine, the study flags calcium, riboflavin (vitamin B2), and vitamin B12 as nutrients of concern. Dairy products are major sources of these nutrients, and plant-based alternatives often contain lower amounts unless they are fortified. Calcium is crucial for bone health, riboflavin supports energy metabolism, and vitamin B12 is essential for nerve function and red blood cell production.

Dr Bath emphasizes that the health effects of iodine deficiency are well-known, and the aim is to raise awareness. She points out that young women and women of childbearing age are the key groups to watch because iodine is particularly important during pregnancy and lactation.

What This Means for Consumers

For those considering a shift to plant-based dairy alternatives, the findings suggest a need for caution. Not all plant-based products are created equal; some are fortified with essential nutrients, while others are not. Reading labels and choosing fortified options can help mitigate the risk of deficiency.

Moreover, the study underscores the importance of dietary diversity. While plant-based diets can be healthy, they require careful planning to ensure adequate nutrient intake, especially for vulnerable populations.

Key Takeaways

• Swapping dairy for unfortified plant-based alternatives may lead to deficiencies in iodine, calcium, riboflavin, and vitamin B12.
• Adolescent girls and women of childbearing age are at highest risk due to low baseline iodine intake.
• Fortification levels vary widely among plant-based products; check labels for added nutrients.
• Partial substitution (20-33%) could significantly increase iodine deficiency prevalence.
• Pregnant women and those planning pregnancy should pay special attention to iodine intake.

Comparison of Dairy and Plant-Based Alternatives

Note: Values are approximate and vary by product. Fortified plant-based milks are designed to match dairy nutrient levels. The background to this story is set out in Plant-Based Milk Hits 10% of Spain's Milk Sales as Oat Drinks Boom. A related thread runs through The Forgotten History of Cretinism: How Iodine Deficiency Ravaged the Alps. Earlier coverage in Ferritin Face: Separating Iron Deficiency Fact From Fiction shows how the argument developed.

Expert Advice and Next Steps

Dr Bath and her colleagues stress that awareness is key. Consumers should not necessarily avoid plant-based alternatives but should make informed choices. Choosing fortified products and maintaining a balanced diet can help prevent deficiencies. A closer look at the same subject appears in Finance: latest articles. Anyone following the wider picture can start with Why Cloakroom Costs on a Night Out Have Soared to £15. The same theme surfaces in Revolut Account Freeze Puts £37,000 House Deposit at Risk, which takes a different angle.

For those at risk, such as teenage girls and women of childbearing age, consulting a healthcare professional or dietitian is advisable before making significant dietary changes. Public health strategies may also need to consider fortification policies to protect vulnerable groups. Context on how this played out before sits in First-Time Buyer UK: Shared Ownership & 95% Mortgages Guide.