I did not read this whole thread because I don't have time.
But on a practical note, I would like to add something for your consideration.
Proper nutrition and supplementation is important if you want to keep up the vegetarian diet and stay healthy so you can keep marching on the path to the liberation.
(As lay people, one of very few advantages we have is we can choose the foods and supplements that we take. The homeless ones cannot do so.)
1. Proper protein intake (must)You need
at least 65 grams (women) to 75 grams (men) of protein from the complete protein source (the ones with 8 essential amino acids).
If you are a vegetarian, you can use dairy product (whey, casein, milk protein), soy, and hemp protein powder to control your complete protein intake to meet the required amount. Dairy product offers the highest bioavailability rate. In other words, its performance is superior than others (only exception is egg white which offers the same highest rate. But since we don't eat egg, I skip egg from this list).
If you are a vegan and don't take dairy product, make sure that you don't rely on Gluten (wheat based protein) which has bioavailability that is very, very low.
I know that Gluten based product are popular but it's not much beneficial to your body.
Juts use soy and hemp based protein strategically.
If the amount of protein you take is much higher than the recommended dosage, then increase the water intake.
If you have weak kidney then add Kidney protection supplement (Cranberry juice extraction capsule. So much cheaper than the juice. Less than 10 dollars a month.).
2. Multi Vitamins and Minerals + Calcium (must)Calcium intake from multi vitamin and mineral is usually not enough.
Add the extra calcium supplement.
You don't need pricey ones.
Just get the cheapest one and it will still work.
3. Vitamin B Complex (must)As some of you said, it is difficult for us (vegetarians) to get Vitamin B-12.
Below is the Super Stress B-Complex that I have been using for more than 2 years.
It covers the whole spectrum (B-1, B-2, B-6, B-12, and more).
http://www.swansonvitamins.com/SW920/ItemDetail(No, I don't work for the above company. I am just sharing the info since I believe this is one of the best deals.)
4. Raw Walnut (option but highly recommended)Someone mentioned dementia/Alzheimer.
Raw walnut is the best and the cheapest protection you can have.
Eat 20~30 grams a day.
Don't take the one that is salted.
Just straight raw ones.
If some of you wonder what would be my qualification to give out the nutritional advices....
I used to bodybuild (from the mid 20s to the mid 30s) and studied nutrition and supplementation along with weight training itself.
I am now 41 y/o and don't bodybuild anymore but I still have knowledge on the subject of nutrition and supplements.
My Masters Degree research project was the developing of community education program for the proper nutrition and supplementation.
So you might consider that there's a possibility that my advice could be a good thing.