I work in the beauty industry and have done alot of research on this topic. From my experiance Biotin has been the only supliment clinicaly proven to help hair and nails grow. Hair and nails are primarily made of keratin and Biotin helps your body produce more. Your hair will shine, thicken, and grow faster.

You should not even worry about calcium or floride I doesn't help hair or nail growth at all it won't hurt you if you take it but it worn't make your hair better.

GNC has a biotin suppliment that is really inexpensive I recomend my clients taking 1 tab of 600mg 2 times a day.

hope this helps.