Agree. The people who successfully transition to a significant diet change like vegan/vegetarian probably already see their primary care physicians. Hence they’re more likely to know they’re deficient. A major diet change would be journaling and testing glucose closely to see what spikes and doesn’t. This is more of a 80/90 thing though and not for everyone.

Personally, I avoid fortified foods because I supplement with higher quality forms elsewhere. Neon yellow urine is not right.