Where can you get vitamin K2?

Getting K2, like getting D, is difficult from food sources. The choices for K2 sources include:

--Natto--generally, an impalatable choice, despite being a common food in part of Japan, which much of the vitamin K2 scientific study originates. I've had it and it was intolerably gooey and weird-tasting. It is, nonetheless, the most concentrated food source of K2.

--Paté--Though liver products potentially contain many other unhealthy things, like pesticide residues, since the liver acts as a filter for the blood.

--Fermented cheeses--Since K2 is a product of fermentation of cheese.

For years, we've advised people to avoid or minimize cheese because of saturated fat or cholesterol content. I think that there's reason to re-think this advice based on the emerging data.

How can you tell the difference between fermented and non-fermented cheese? First, look for the holes in the cheese. The holes are the remnants of gas pockets created during fermentation. Second, look for the word "cultures" on the label, meaning organisms for fermentation were added. If "processed cheese" is anywhere on the label, this is a dairy product that has been chemically coagulated and is not fermented. Fermented cheeses are generally "gourmet" cheeses, not eaten a pound at a time on a pizza, but meant to be eaten in small portions, e.g., with a glass of flavonoid-rich red wine.

Because of the limited food sources, some people interested in taking advantage of the potential coronary calcification-inhibiting effects, or osteoporosis-preventing effects, have resorted to nutritional supplements, which usually come in 100-1000 mcg dose tablets.

The data on vitamin K2 have shown no toxic effects of this naturally-occurring nutrient, even in doses as high as tens of thousands of micrograms, similar to that found in natto.

How much fermented cheese is necessary for its presumed inhibitory benefits on coronary calcification and osteoporosis? Are some fermented cheeses better than others? These issues remain unsettled.

We clearly need more study of this fascinating and promising nutrient. Should we all begin to supplement vitamin k2 in our diet? The studies I cite above, along with some of the eroding arguments that caused us to avoid saturated fat sources, at the very least might invite traditional fermented chesses back into our diets. Beyond this, let's wait and see.