Biotin Years ago, someone noticed that animals given biotin grew stronger hooves. Used alone, one or two mg. Biotin is generally considered nontoxic. At present, most of these clinics are quite expensive and the biotin preparations are not available for general sale. The best food sources of biotin include liver, kidney, egg yolk, haddock, halibut, cod, salmon, and tuna.
Vegetables generally contain much less.
Many of us have observed that taking calcium seems to improve nail quality. Remember that calcium and other minerals don't absorb well unless the stomach is making sufficient hydrochloric acid and, that as we grow older, more and more of us have underacidity problems. For a few of us, too much zinc and too little copper can result in hair loss. Although this situation isn't common, it should be checked for when the more usual answers aren't working. Women and men have both estrogens and androgens.