In this post I mentioned taking Biotin suppliments for healthy hair and nail growth. I did a little more research on this suppliment and found this interesting tid-bit on Wikipedia's entry on Biotin:
"Biotin is often recommended for strengthening hair and nails. As a consequence, it is found in many cosmetics and health products for the hair and skin, though it cannot be absorbed through the hair or skin itself.
Biotin deficiency is rare because, in general, intestinal bacteria produce biotin in excess of the body's daily requirements. For that reason, statutory agencies in many countries, for example the USA and Australia, do not prescribe a recommended daily intake of biotin."
I had no idea that we created our own supply of Biotin! 5000mcg is still the accepted dose for improving hair growth and I've personally found that this is the minimum amount that my body needs to improve the speed and condition of the growth of my hair and nails.