Vitamin D is known for being the "sunshine" vitamin, because sunlight is such a great source of this immunity-boosting, bone-friendly nutrient. But could vitamin D also help protect you from some horrible diseases? A March 2018 study out of Japan might shed some new "light" on a possible link between the vitamin and a lower risk of some cancers — with a few caveats.
The new research, published in The BMJ, studied 33,736 people between the ages of 40 and 69 years. At the beginning of the study, the participants provided info about their medical history, diet, and lifestyle choices. Next, they had blood samples taken to measure their vitamin D levels. They were split into four groups, ranging from the highest to lowest levels of vitamin D, and then, they were monitored for the next 16 years.
During that time, the researchers recorded 3,301 new cases of cancer among the participants. After they adjusted for known cancer risk factors — like smoking, weight, and age — they found that a higher level of vitamin D was linked with a 20 percent lower risk of overall cancer in both men and women.
But before you run out and buy every vitamin D supplement in sight, keep in mind that this study did not prove that getting lots of vitamin D causes a lower risk of cancer; rather, the study found a connection between a high level of vitamin D and a lower risk of some cancers — including liver cancer — over a period of 16 years. No such link was found for other cancers — including lung cancer — in the study. It's also worth noting that this study has some other limitations, including that the numbers of some organ-specific cancers were pretty low. Also, they can't rule out the possibility that other factors might have ultimately led to the results.
That said, the researchers say their findings support the idea that vitamin D may protect against the risk of some kinds of cancer. However, they think there might also be a ceiling effect — meaning there are no additional benefits beyond a certain level of vitamin D. More research is needed to find out the "best" levels of vitamin D for cancer prevention in people.
Remember: Always talk to your doctor first before starting any new supplement.
Next, learn some surprising facts about cancer in the video below: