Hair Growth Remedies

I’m not talking a miracle hair growth vitamin or anything like that. I’m also not talking about something that would make my hair grow insanely fast because I know that’s not possible. I’m asking what vitamin, you know like A B C D ect… that would promote hair growth…my hair doesn’t grow at a normal rate these days and Im thinking that I may be missing something in my diet??? So what vitamin if any is know for promoting heathly hair growth and nail growth ect?

If one parent has really fast growing hair, and the other has slower growing hair, then would the offspring have an average hair growth rate or would it be faster or slower? Or does the hair growth rate have anything to do with dominant and recessive genes at all?