A recent study from Switzerland demonstrated a 25 percent increase in nail plate thickness in patients with brittle nails who received biotin supplementation. Analysis of all visits to a nail consultation practice over a six-month period revealed forty-four patients with this condition who had been prescribed the B-complex vitamin biotin. Of these, thirty-five who took daily supplementation were subjectively evaluated. Twenty-two of thirty-five (63 percent) showed clinical improvement and thirteen (37 percent) reported no change in their condition. The results of this small, retrospective study suggest a positive response to biotin in the treatment of brittle nails in some patients.