A study appearing in the American Journal of Epidemiology (Volume 167, Issue 3, 1 February 2008, Pages 313–320) looked at vitamin K and its role in inflammation. Vitamin K protects against cardiovascular disease and osteoporosis. This observational study suggests that the reason for this is that it fights chronic inflammation.

The study used data from 1,381 subjects from the Framingham Offspring Study. It looked at vitamin K status of the subjects, whose average age was 59, by looking at serum levels of the vitamin and by analyzing dietary intake.

The study then looked at the presence of 14 different inflammatory markers (substances in the blood that show inflammation). The researchers found that high vitamin K intake and blood levels were associated with lower inflammation. They found that increased vitamin D levels may lower oxidative stress—but the anti-inflammatory effect of vitamin D was less consistent.

There are two forms of vitamin K. Pylloquinone, also known as vitamin K1 is found in green produce, like spinach and broccoli. Vitamin K2, also known as menaquinones, is produced by normal bacteria in the intestine.