Ola! /images/graemlins/smile.gif
You know you asked a lot of great questions. First I want to recommend a book that was a good "starter" Earl Mindell's Vitamin Bible, I think he has an updated version and it's a great read to help learn about vitamins.
As for vitamin brands,there are a lot of brands that people like and have recommended on this board and they are:
Puritan's Pride for Biotin (they take five 1000 mcg per day)
Kal for Silica it's called Super Silica Plus
Natrol for Silica, I personally went through two bottles of this and didn't really see anything great
I love TWINLABS for my B-Complex and my B-5 (B-5 increases the thickness of your hair strands, as in it actually grows in thicker.)
Also Solgar usually has quality vitamins as well.
I know that if you stop taking the vitamins I think your hair will go back to being how it was. So if taking vitamins increased your growth rate, I think if you stopped, your growth rate would slow down to what it was before vitamins, so you asked some great questions.
Another great supplement is MSM and for many it has increased growth spurts, here is a
LINK TO A THREAD about the brands of MSM that people liked. Also here is another
MSM Review thread from users on the board.
The Downsides of MSM have been headaches, and acne. The upside has been growth spurts in hair and nails. Also some women complain that with certain B vitamins (Biotin I believe it was) their periods become irregular, although I have not experienced this myself.
Below are some links to the places to purchase vitamins on line.
Link to Puritan's Pride
The link to the Vitamin Shoppe
I know I gave a loooong post, so I hope you don't mind, but I wanted to answer your questions to the best of my ability and I'm sure others have more to add.
If you have more questions, please don't hesitate to ask us.
HTH (hope that helped)and WELCOME!!! /images/graemlins/grin.gif
Tara