Dale Vince, founder of the Green Britain Foundation, has clarified that cow's milk is not a natural source of iodine but is fortified at the cow, responding to a study suggesting that shifting from dairy to vegan alternatives could lead to micronutrient deficiencies.
Fortification at the cow
In a letter published in the Guardian, Vince explains that iodine is present in milk because it is added to cattle feed. He also notes that vitamin B12 in milk results from cobalt being added to the feed, enabling the cow's gut bacteria to produce it. Britain has followed this practice for decades.
Plant milk fortification as the answer
Vince argues that if fortification is the solution, as the study's authors suggest, then plant milks should be fortified instead. He asserts that this would be better for both human health and the planet compared with cow's milk.
The study, published in the Lancet Planetary Health, assumes that every plant product on the shelf is bought in equal measure, but Vince points out that they are not, and the most popular brands are already fortified with iodine. He concludes that the study's deficiency figures are therefore overstated.
Dairy's climate burden
Vince highlights that dairy is one of the heaviest climate burdens on our plates and that most of humanity cannot digest it past childhood. He states that moving away from dairy is the right direction and that the answer to a fortification gap is fortification itself, not urging teenage girls to return to dairy. He concludes: "We need to leave cow's milk for baby cows."
