Please also keep in mind that if you are taking massive doses of any B Vitamin, you must take it in a complex or it will pull the other parts of the B Vitamn from your body to complete a complex - thereby actually causing more deficiency.
I tried massive doses of Vitamin B5 (also known as Pantothenic Acid) for Acne problems, under the care of my naturopath, I even took it with a complex and still had massive hair loss, which is a known side effect of dosing B5. It is just now growing back.