Anybody under 55, listen up—there has been a dramatic increase in the likelihood you or somebody you know will be diagnosed with colon cancer in early adulthood or middle age. And while the exact why is currently under investigation, there is one interesting finding related to your blood levels.

“We’re finding that people diagnosed with colon cancer have low vitamin D levels,” says vice president of in-office care at One Medical Natasha Bhuyan, MD. And while the correlation is still a bit chicken-or-the-egg (“this discovery is in the really, really early stages,” Bhuyan adds), there’s something else to note: results from a couple of studies like this one and this one, which reveal a “deficiency of vitamin D increases the incidence of colon cancer and also has a negative impact on the survival of colon cancer patients,” it might be time to ask to have your levels looked at the next time you’re at the doctor.

Only a blood test will officially reveal if you’re deficient. But with research showing that almost a billion people on the planet are deficient in vitamin D, it’s worth asking your doctor for a test next time you’re getting a physical.

Vitamin D plays an important role in both our physical and mental health, helping build strong bones, keep the immune system strong, and balance mental health. Bhuyan advises that there are actually a variety of ways to keep your vitamin D levels healthy. “Some people will eat a vitamin-D-rich diet or fortified foods,” she says. “There’s also the option of taking a vitamin D supplement or spending time in the sun because that helps your body make it naturally. But we always advise you to be really cautious about spending time in the sun, because it can also increase your risk of skin cancer.”

And while the new diagnosis statistics are startling (“diagnoses of people under 55 years of age doubled from 11% (1 in 10) in 1995 to 20% (1 in 5) in 2019,” reads a press release from the American Cancer Society) for Gen Z, Millennials, and Generation X, knowledge can truly be power in this instance. And maybe eating more vitamin D can be, too.