You have probably reached for oat milk at the coffee shop, or picked up a vegan cheese thinking it was the healthier choice.
Many of us have made that swap without a second thought. It turns out the trade is not as nutritionally even as it looks.
A new modeling study from the University of Surrey and Queen's University Belfast looked at unfortified plant-based alternatives.
Replacing dairy with them lowers intake of four key nutrients, even in partial swaps. Iodine takes the biggest hit.
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Calcium, vitamin B12, and riboflavin also fall.
Iodine is the one most people have never thought about. The thyroid uses it to make the hormones that regulate metabolism, and a shortage during pregnancy can affect fetal brain development.
Milk, yogurt, and cheese are among the main everyday sources.
The researchers modeled the diets of more than 3,500 people, from toddlers to 100-year-olds, using UK national survey data. They also checked 289 plant-based products on shelves. That included 146 milks, 76 yogurts, and 67 cheeses.
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Just 12 percent of those products had iodine added. Calcium appeared in 61 percent, vitamin B12 in 46 percent, and riboflavin in 19 percent.
Young women and teenagers take the biggest hit
Replacing 20 to 35 percent of dairy with unfortified alternatives pushed iodine inadequacy in teenage girls from 54 to 65 percent. In women aged 19 to 49 it rose from 32 to 42 percent.
A full swap raised inadequacy to about 80 percent in teenage girls, according to the paper in the Lancet Planetary Health.
The authors called for mandatory fortification of plant-based alternatives, with iodine singled out as the hardest nutrient to replace.
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Adults need 150 micrograms of iodine a day, and pregnant women need 220 micrograms, according to the NIH Office of Dietary Supplements. One cup of cow's milk provides roughly 85 micrograms.
Most plant-based milks provide only a few micrograms per cup, because iodine is rarely added since it can alter the flavor.
What to check on the label
Before you put a carton in the basket, read the nutrition panel. Look for added iodine, calcium, vitamin B12, and riboflavin.
If none of those appear, the product is contributing far less to your daily intake than the dairy version it replaced. For anyone who is pregnant, trying to conceive, or raising teenagers, that gap matters most.
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If you cannot find a fortified plant-based option, a conversation with a doctor or dietitian can establish whether a supplement makes sense for your household.
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This article is made and published by Ida-Marie Palm Varbæk, who may have used AI in the preparation.