The Beauty Bar: Biotin for Brittle Nails

By Kim Erickson

If you have brittle nails that often split and peel, a daily dose of biotin could help. This little-known B vitamin contributes to the formation of keratin—an extremely strong protein that is a major component of nails.

What to Take: The federal recommendation for biotin is just 30 mcg a day—enough to prevent a deficiency. But most studies of biotin’s nail-strengthening benefits use considerably more. During one controlled trial using 2,500 mcg of biotin per day, the participants’ nails became 25 percent thicker—which translated to stronger nails with less splitting. Another study by researchers at Columbia University in New York City found that 63 percent of people who took the same dose of biotin showed improvement after six months. While taking that much biotin may seem extreme (and possibly dangerous), no one has reported any toxicity even in high amounts, says Elson Haas, MD, founder and director of the Preventive Medical Center in San Rafael, California. The body simply eliminates any biotin it doesn’t use through urination.

Keep in Mind: Sources of dietary biotin include egg yolks, soy, avocado, and peanuts—and these foods provide enough to maintain healthy nails, says Missouri-based dermatologist Jerry Aronberg, MD. “But for brittle nails, I’ve found that taking even 1,000 mcg of supplemental biotin will reverse the problem,” he adds. You may not notice any improvement for several months, so be patient.

We Like: Source Naturals Biotin (600 mcg, 200 tablets) and Nature’s Way Biotin (1,000 mcg, 100 lozenges).