How Long Would Vitamin Deficiency Take to Correct?

Hello Dr.
I can’t seem to find a definitive answer to this question on the internet for some reason. I was wondering how long you think it takes to correct a vitamin deficiency? I am trying to see if my seb derm and subsequent hair loss are as a result of this, yet I want to know how much time I should give it before I determine whether or not vit def is the culprit? Thank you for your time.

Your analysis is guess work. How do you know you have a vitamin deficiency? Did you get test to confirm this?

I can not endorse your approach to your problem. See a good dermatologist who knows about hair and the various conditions you seem to report. I wouldn’t advise treating yourself.