If someone starts getting grey hairs, can they go back to growing normal hair color again?

No, once it is gray, it is gray for life.

I don’t think so, but if someone else knows otherwise, I want whatever the vitamin is that does it.

No, on second thought, I don’t. I get lots of compliments on my salt-and-pepper hair.

Yes it can.
I don’t know why, but I have had this happen to me.
I found my first white hairs very early, I was 10 years old. By the time I was 15 I had quite a few.
Over the years I have found hair growing out of my head that was white on the older end and brown on the growing end. Sometimes I would find them going back and forth from brown to white to brown again. My hair has always been fairly long, so there was length there to see the change.
My hair also stopped turning white and maintained what was still brown during my pregnancies. (Although I don’t think there was an unusual amount of hair going back to brown during that time.)
I don’t know why, I don’t know how, but it can and does happen.

I guess if it can happen to you and Benjamin Button it can happen to anybody. ;-)

It had seemed I was getting more grays, which means I might have had 15, and it seems I only have a few now. I also have been losing a lot of hair, so for all I know I just have less Hair. Sigh, it is very depressing to me. Anyway, I wanted to know if it is medically possible, or am I just imagining things.

@wilma Sounds like some sort of deffeciency to me, might be caused by your genes. That would fit with the pregnancy fixing the problem temporarily.

Otherwise I’d say Chernobyl 2012 is the place to be.

@Zyx genetics is most likely the reason. My father and his mother’s family all very white very early.
I have never colored it, I just couldn’t be bothered trying to look somehow different that I really was.