Dear Louis
I will be honest and tell you that my natural tendency is to stay away from any cult. In many ways vegan(ism) and vegetarianism is becoming a cult because of the business industry.
The yeast that is sold in powders is dormant. The life force energy is not flowing in there... You might get B12 but keep in mind there are so many factors that are involved in proper nutrition - factors that we don't fully understand because most vital processes were studied in isolation. However it is all like a domino effect or in other words everything depends upon something else.
Yeast needs water, sugar, air, some food substrate such as ground cereals and warm temperature to become active. Once it does it grows amazingly fast. And I have just described the recipe for bread. Good old traditional bread. I have this thing of staying away from any supplements. If you really want B12 go buy a loaf of brewers yeast that is fresh you know the one for bakery and just eat a chunk - see how you feel after. I remember eating it as a child, and I quite liked it.
However you have to keep in mind your body as a whole.
Everybody is different also. That's why I am with Julia when it comes to food, and about everything else: listen to your body... listen to the language of love... love your body... Love is a powerful word here because to some it may be synonym with indulgence, which is not... and is also not synonym with deprivation...
Your body knows better that anybody any health food advocate or expert in nutrition what it needs. By all means educate yourself in what is good for you!!! - honestly when I moved to this continent I was in shock at the eating habits of the North American people, and the high % of obesity. I would have never imagined that people can reach such mass.
My apparent overweight was a joke. In french culture you take the height of a person in m and cm. (the international system of measurements). So let's say Laura is 1.64 tall (1 meter and 64 centimeters) her ideal weight should be: 64-10 = 54 Kgms My whole adult life I was hoovering at 64 (I was fat according to frenchies!!)
Over here the ideal health scales are much more lenient - over here my weight versus height is perfect

(yeyyy..loll) - however how many are even inside of these scales?
I better stop here ..lol..
Anyway when it comes down to it we have to listen to our bodies - because what works for me might not work for you etc...
I also thought last night about this braetharian thing. To my knowledge there is no being in nature living as such. Also I have never heard about any master not eating. Food was not a focus in their lives and they could easily go without for lengthy times, but still they eat.
In this physical world everything is tomorrow's food.
I am not saying is impossible and that spirit can't raise you to that state. It all comes down to other far out stuff such as becoming a being of light etc. When and where are we supposed to leave behind the physical form?
love - Laura