I've already said pescetarianism is the most healthy diet for humans. The meat industry is not sustainable or environmentally friendly, so no. I don't see an issue with taking supplements. Omnivores actually should also be taking supplements, the majority of people are not getting all the vitamins in a day that they are supposed to and are deficient in something. The one way i could see meat being an okay and humane thing is "super meat" which actually is sustainable and much cheaper/better fir the environment. It's real meat but rejenerated like the way doctors will take some of your skin and have the cells multiply for ppl who need skin grafting. A lot of meat eaters are weirded out by that tho.