I am always trying to learn more about nutrition. The one thing that I have understood is that any nutritional component (protein, vitamin, mineral, enzyme), is one part of a whole picture and the health of the body is dependent upon ALL nutritional elements being provided for it, all the time.
I have associated the Vitamin B Complex with the support of brain hormones (moods and mental clarity) but recently I learned that the Vitamins B12, B6, and Folate, or Folic Acid, are all necessary for the conversion of the muscle building foods we eat, to the muscle tissue that dancers so direly need.
Protein from beef provides B vitamins, though it is much more abundant in the beef liver than in the muscles meats (steak!). Does every dancer eat beef liver 5-7 times a week? Not likely.
I think therefore that adding B vitamins to the diet as a supplement is pretty well mandatory for dancers and all athletes - and growing children and....well who would be exempt? Whole food supplements (vitamin pills made from food and not made in a lab) would be my choice.
Get one of these well-formulated supplements to process muscle building foods.