Biotin supplements are revered by some clients for the improvements they make on nails and hair, even though some medical professionals remain skeptical. "As long as people get enough biotin in their diets, it has never really been proven that additional biotin has any effect at all on nail health," says Robert Brodell, MD, professor of internal medicine, dermatology, at Northeastern Ohio Universities College of Medicine in Rootstown, Ohio. "But I have had patients tell me that biotin has worked for them, and one milligram of biotin taken daily is certainly safe. Some people have even told me that calcium supplements work for them. I encourage people to conduct their own trials."