Yes vitamins will double the growth of your hair. But taking more vitamins now can effect your
other systems in the future. So you need to take calculate the dose of vitamins now.
Prenatal vitamins and pregnancy can make your hair grower faster, fuller, and shinier. It's the hormones and extra vitamins and minerals in your body. But it will most likely change back to normal after having the baby.
If you're pregnant it's not the vitamins that are causing your hair to grow and get stronger, it's the hormones. If you are not pregnant buy a supplement that is specified for hair growth and strength.