I agree with David. It's just not that hard for vegans to get all necessary nutrients. many vegetables are loaded with calcium and B12 certainly isn't hard, either. I've been vegan for nearly 30 years and have no problems w/ B12 or calcium. I do take a high-quality, high-potency multi-vitamin because my diet is lousy, and because I have to take high doses of iron and vitamin C help the uptake of iron. So, rather than just taking C, I get it in a multi. (I don't take iron because of diet, it's a medical issue.)
I think we have to be careful of making it sound difficult (or worse, dangerous) to be vegetarian or vegan.
To answer the OP... Count me among those who aren't focused on nutrition. Maybe I should be, but I enjoy having a mere nodding acquaintance with my kitchen these days.