I have multiple sclerosis & for years i have been taken 5,000 or 10,000mcg of biotin. so my questions is what is the correct & safe mcg i should be taken? thank you?

Biotin has been investigated for use in progressive Multiple Sclerosis, but despite the promise of early studies, a large followup study did not confirm any benefits beyond placebo. So there is no recommended dose at this time. High dose biotin does interfere with lab results (i.e. thyroid). So please inform your treating physician if you plan to continue taking this.

Disappointing but no good evidence that Biotin has any current role in MS, whatsoever. Your best bet is Vitamin D-3, and use of a high efficacy infusion or oral treatment. Discuss with your neurologist. Cannot recommend continued Biotin.