Fingernail Problems

Beating Brittle Nails

It’s true that they are the perfect way to display the latest fashion colors. But don’t sell fingernails short. Besides protecting your sensitive fingertips from the abuses of daily life, they can tell you a lot about whether you’re eating right.

Like bone health, nail health depends on good nutrition. Brittle nails have been associated with deficiencies of calcium, zinc and iron and with too much selenium. And slow nail growth can result from general malnourishment.

But so far, only one nutrient—biotin, part of the B-complex—has been proven helpful for nail health in people who aren’t malnourished. You can thank veterinary science for that bit of information. Biotin has long been used to help harden horses’ hooves.

Here are the details.

Biotin Banishes Brittle Nails

A study by Swiss researchers looked at people with apparently normal intakes of biotin: 28 to 42 micrograms a day. Researchers found that people in the study with thin, frail and split nails who took extra amounts of biotin—2.5 milligrams (2,500 micrograms), or roughly 70 times the average daily intake—experienced a 25 percent increase in nail thickness.

“Biotin is absorbed into the matrix of the nail, where it may help correct brittle nails,” explains Richard K. Scher, M.D., dermatologist and head of the nail section at Columbia Presbyterian Medical Center in New York City. (The matrix is the part embedded in the finger where nail cells are generated.) Dr. Scher recommends biotin supplements to his patients with weak nails. “It seems to help about two-thirds of them,” he says.

The amount of biotin used in the Swiss study is very high. This dose should not be taken except under medical supervision.

Top dietary sources of biotin are egg yolks, soybean flour, cereals and yeast. Cauliflower, lentils, milk and peanut butter also provide decent amounts.