Vitamin B12 is one of the most recent vitamins to be discovered, it was discovered in the late 1940’s. Vitamin B12 is required by the body in small amounts, however vitamin B12 is only found in significant quantities in animal foods. The most abundant sources are liver and kidney, followed by other meats, fish and cheese. Vegetarians are often recommended to eat fermented foods like tempeh which are thought to be good sources of vitamin B12; however there is some evidence that the form of Vitamin B12 in these foods is not exactly the form that meets our bodily requirements. This is often the reason why vegetarians and vegans may feel that it is necessary to supplement with vitamin B12. A recent study concluded that long-term supplementation using 100mcg’s of B12 combined with 400mcg’s of folic acid improved cognitive function after 24 months.