People with a condition known as fingernail onychoschizia (brittle, splitting nails) treated with the B vitamins biotin and pyridoxine (vitamin B6) for three months showed improvement in their condition six to nine months after beginning treatment.

Nail brittleness describes a condition in which nails become soft, split, crumble, flake and lose elasticity. Splitting of the nail ends is common in people who have this condition.

Preliminary research findings have suggested that vitamins, including the B vitamin biotin, may be beneficial. Biotin is a cofactor for enzymes involved in the formation of proteins that include keratin, found in hair, skin and nails. Vitamin B6 is a cofactor for enzymes involved in amino acid metabolism. (Amino acids are the building blocks of protein.)

“Our data showed that a 3-month daily dose of 1 mg biotin with 100 mg pyridoxine (combined treatment regimen) was found to be highly effective,” authors Avner Shemer, MD, of Sheba Medical Center in Israel and colleagues wrote. “This treatment regimen was shown to be superior to oral biotin or pyridoxine taken alone.”

While 10% of the individuals in the study who used biotin alone and 11.1% of those who used vitamin B6 alone had complete or almost complete resolution of their condition, defined as over 90% improvement, 69.6% percent of the combined biotin and vitamin B6 group achieved that level of resolution. Marked improvement (between 50% and 90%) occurred among 45% of those who used biotin alone, 38.9% of people who used only vitamin B6 and 30.4% of those that used combined treatment. Thus, all subjects in the study who received the combination vitamin treatment experienced a 50% or greater improvement.

The retrospective study involved 4 men and 57 women between 20 and 68 years of age. Twenty subjects consumed 1 milligram (mg) per day biotin, 18 consumed 100 mg per day vitamin B6 and 23 used both vitamins for three months. Nail condition was assessed 6 to 9 months after the beginning of the treatment regimen. The findings were published in the February 2025 issue of the Journal of Drugs in Dermatology.¹