You can also take supplements such as silica gel, and things like zinc,iron, folate, etc.
Remember also 3 things- 1. liquid supplements absorb better than tablet form, 2. some vitamins and minerals can inhibit the absorption of others, and 3. they will take a few weeks to months to show results.

I have liquid iron and multivitamins in orange juice (which is best taken first thing in the morning on an empty stomach) and I take silica gel in my water.

As for biotin, I have taken it in tablet form, where I am it isn't easy to find a solely biotin supplement and in a higher dose. In looking at reviews in the past it seems to work, but it's not the only thing that helps hair and nails to grow, hence why I take a variety.