Biotin Vitamin: A necessary vitamin for cell growth and producing fatty acids. 

It is instrumental in the metabolizing of fats and amino acids. 

It has a functioning role in the Citric acid cycle for generating energy during aerobic breathing. ( that labored exhale/inhale.) It has a very important role of transferring carbon dixoide. It is the fuel that maintains normal sugar levels.  As if this was not enough positive actions to keep us balanced, it strengthens our hair and nails.  Because of this, it is found in a lot of cosmetics and health skin products.

As Biotin is produced naturally in our intestinal walls, to maintain a balance with the bacteria found there, some will say that we don't need to take it as a vitamin, but those whose suffer from chronic diarrhea or Chrohn's disease, may have very well thrown that bio system out of balance, and find it necessary to provide additional Biotin to their systems.

Some  nutrients that contain a very high amount of biotin are: Royal jelly and brewer's yeast.  Some foods for human consumption, containing biotin are:
cucumber
soy
swiss chard
legumes
tomatoes
onions
cabbage
eggs
almonds
walnuts
goats milk
cows milk
rasberries
strawberries
oats
halibut