Dairy products a good source of some types of Vitamin K

Vitamin K, with its multiple forms, is among the lesser known nutrients. Now, new research from scientists at the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University sheds new light on the vitamin and its significant presence in some dairy products.

In the study, published in Current Developments in Nutrition, researchers quantified the activity of two natural forms of vitamin K in dairy products of various fat contents and found that common U.S. dairy items, including milks, yogurts and cheeses, contain appreciable amounts of multiple forms of vitamin K. Vitamin concentrations varied by fat content.

Vitamin K, which helps the blood to clot, is most commonly thought to come from leafy greens such as spinach, kale and broccoli. In fact, dietary sources of vitamin K are found in two natural forms: phylloquinone (PK, or vitamin K1), which is widely distributed through plant-based foods, and menaquinones (MK, or vitamin K2), which appear to be primarily in animal products and fermented foods.