Do you really think any diet plan where you need to pop pills not to become deficient is natural?
Natural? Arsenic, absinthe, ricin, and amotoxin are natural. Do you consider hormones in your meat and dairy products natural?
You can either take a B-12 supplement or sprinkle nutritional yeast (not brewers, that stuff reeks) on your food.
It's funny to me how people decry the unhealthiness of veganism, to which I say I dare you to walk into any stroke, cancer, heart disease, diabetes, etc. unit in a hospital and find me a single vegan.