How much and which vitamin b should you take to stop hair loss?

Biotin: Hair loss is a complicated issue that can be caused by many things, ie overproduction of dihydrotestosterone (dht), autoimmune disease, & hypothyroidism. For the sake of answering this question on vitamins, the winners go to biotin & dexapanthenol. These ate two vitamins necessary for hair production. Quality is important so do your research.