Hi gang!
I must change my thread settings as this keeps falling of my active threads list! Or, I should post a lot more often. 
About going vegan, I did the same as lentil, I first of all became veggie - simply to avoid BSE - then gradually, as my awareness grew, withdrew from dairy, eggs, etc. Finally, I had to give up Drambuie when I discovered it contained honey. That all took about 18 months, but, if I had my time over, I'd have gone straight into veganism.
As I said earlier, I don't feel the need for supplements as long as I keep up with my flaxseeds, but I do eat Marmite (or the cheaper own brands) most days and my nooch is fortified with B12.
And I had a blood test a couple of months ago which said my B12 was fine.
I do have a couple of successes to report: I was very concerned to find out that Pure contains palm oil, which I'm trying to avoid, so - I've developed a vegan pastry which only consists of s/r flour, salt or sugar, water and either veg oil or olive oil.
I've made both savoury and sweet pies in the last couple of days, and, although I say it myself, they were both pretty good!
But my biggest achievement has been to persuade a Portuguese hotel to cater for vegans - and they rose to the challenge magnificently! 
All these are featured on the first page of my blog, along with other vegan recipes.