The idea is that vegans need supplements or fortified foods and therefore veganism is an "inferior diet"
What about all the fecal contamination, hormones, antibiotics, and preservatives in meat? This is to say nothing of the carcinogens released in cooking all meat and saturated fat that makes heart disease the number 1 killer. Shouldn't a diet be better measured by the garbage it doesn't contain?
There's nothing wrong with eating fortified foods as part of a balanced diet. The idea that a vegan diet is inferior in nutritional quality is already debunked.
Avoiding taking a multivitamin is insufficient justification for slitting an animal's throat, and doesn't make your diet nutritionally superior or ethical