4 Fascinating Things Every Woman Should Know About Gray Hair

Gray hairs often have a different texture than your non-grays. "They tend to feel a little bit drier and a little bit coarse," says Kristin DuFour, an advanced color specialist at the Sam Brocato Salon in New York. "A lot of that can be attributed to the fact that the hair follicle actually changes, because it's not producing melanin anymore." That change in texture is also a reminder that your hair doesn't turn gray—the change happens in the follicle, which means it grows gray.

Caucasians tend to have the most premature graying, says Binh Ngo, MD, a clinical associate professor of dermatology at USC's Keck School of Medicine, usually seeing some gray by the time they hit their 30s. People of Asian descent typically start to see some gray by their mid-30s, and African-Americans don't start to see gray until their mid-40s.

Certain vitamin deficiencies are linked to premature graying, and B12 deficiency has the strongest evidence behind it, says Ngo. "B12 is involved in hair recycling and growth," Ngo explains, so when you're not getting enough of it, it can affect the color of your strands. One study published in The International Journal of Trichology found that levels of B12 were significantly lower in people with premature graying than in those whose hair hadn't started to go gray yet. Ngo says that there's also some research linking a lack of vitamin D to premature graying, but that more studies need to be done to confirm it.

"For most women, gray hair tends to be more resistant to absorbing color," says DuFour. "It may have something to do with the difference in texture." Your colorist may need to use a different formulation to get your new grays to take your favorite hair color. And you may need to reconsider what color you go with. "The hair color spectrum runs from level 1 to 10, 10 being the lightest blond and 1 being black," explains DuFour. "Levels 8 through 10, like light blonds, are not really designed to give you full gray coverage because they don't contain the pigment necessary to cover it up." (If you're looking for inspiration on how to embrace your grays instead of covering them up, check out these seven amazing gray hair makeovers.)