We clip ‘em and file ‘em and paint ‘em with polish. And every 6 to 9 months, we grow a complete new set of nails, say dermatology experts. So how do we keep these functional beauty statements strong, flexible and lookin’ good?

Take a look at your nutrition. Our nails get much of their strength from proteins called keratins.

Adequate fluid intake helps keep nails flexible. And minerals such as magnesium, iron, zinc and copper help them grow strong.

Calcium is incorporated into nails as well, but surprisingly does not contribute as much to nail hardness as we might think.

What to do with nails that are brittle? One nutrient that shows promise is biotin, a B-vitamin (B-7) that helps convert our food into energy. Biotin is also known as vitamin H (don’t ask me why).

Veterinarians first noted the value of biotin when they saw it helped heal brittle hooves in horses. In humans, biotin might increase the thickness of fingernails and toenails in people with brittle nails, according to the National Institutes of Health (NIH). Don’t look for immediate results however. Because biotin is involved in the new growth of nails, the process could take six months or more.

How much biotin we need is another question. No recommended daily intake currently exists for biotin. Instead, the NIH has set an “adequate intake” for adults at 30 micrograms.

One dietary supplement called “Killer Nails” contains 5,000 micrograms of biotin. Is that too much? No one knows. What we do know is that 1,000 to 3,000 micrograms were used in research studies that demonstrated increased nail thickness. And no adverse effects were seen in these high doses.

Do we get biotin in our diet? Why, yes, we do. Biotin is found in a variety of foods including nuts, eggs (especially the yolk), soybeans and other beans, peanuts and other legumes, wheat bran, oats, fish, pork, avocados, yeast and liver. Biotin is also manufactured by the good bacteria in our gut. So deficiencies of this nutrient are rare.

Most reliable multivitamin formulas also contain biotin.

One caution if you’re tempted to eat your eggs “Rocky-style.” Raw egg whites contain a substance that prevents biotin from being absorbed by the body. Cooked eggs are a better option.

After reviewing her research on this topic, I asked Jacqui, our nutrition intern, what she would say to someone who wanted to take a supplement like “Killer Nails” for brittle nails?

Being a smart nutrition professional, she smiled and said, “Look at your diet first. Several nutrients besides biotin support nail health.”

And if you think your nails might need a boost of biotin? “It’s worth a try,” she says.

I would agree.

Barbara Quinn is a registered dietitian and certified diabetes educator at the Community Hospital of the Monterey Peninsula.