Prenatals and hair growth

Naomi
Okay so I have always had long dark (virgin) hair and then out of the blue I decided that I wanted to chop my hair off and dye it as well for the first time. I wanted to go for an ombré but the stylist I went to did a balayage on me Instead and also bleached my hair twice in order to achieve it, thus leaving me with short damaged hair :( I hated the color it left me with so I now dye my hair dark (similar to my natural hair color) I want to grow it out fast to cut the damaged part but I was wondering if any of you all know if prenatal vitamins speed up hair growth and if so, are they bad for your health If you are not pregnant. Here are some pictures of what my hair used to look like (before the cut and dye) and what it looks like now. 
Before (natural pretty long hair which I miss 😕)
With cut and dye 
Then after I dyed it dark brown. With the cut