Vegans in Europe have significantly lower baseline selenium intake (mean 41 µg/day without supplements) and serum selenium concentrations (mean 64 µg/L) compared to omnivores (mean 62 µg/day and 76 µg/L), indicating a higher prevalence of suboptimal selenium status in vegan populations.

When people eat very little selenium, their bodies cannot make enough selenium-containing proteins that carry selenium in the blood and protect cells from damage. The liver makes one key protein to ship selenium to other tissues, but without enough selenium, it makes less of it. The kidneys make another protein that fights cell damage, but it only works if there is enough selenium available. If selenium is too low, this protective protein stays inactive. Even when selenium is added back, some forms are stored in muscles instead of being used right away, so they don’t fix the problem quickly.