When the culture decided eating meat was bad, we gave up one of the best sources for B vitamins. Good grass fed beef is the source of a large amount of B vitamins. There is no other source better than beef.
When people think about eating beef they picture a large steak. This is too big of a serving. Half of an average sized steak is all you need to maintain healthy B vitamin levels.
B vitamins are responsible for giving us energy, good digestion, clear thinking and fertility just to name a few. Other sources such as broccoli would require you to eat several serving in order to get the same amount you would get from half a steak.