Perhaps, my google skills fail me but I can't find an average for how much K2 is in grass-fed butter. Anyone know?
EDIT: If K2 levels are as low as they seem, is supplementation a good idea?
I knew I'd stumbled across information regarding the K2 content of foods somewhere in Stephen's blog. A good 30 minutes of digging and I've finally found it. See the link for a more readable format of the listed values or better yet, head to the linked (below) german database:
In the comments, Lee said...
I have been looking at the German food database, which is available in English. It is interesting since it gives values for amounts of vitamin K in a wide range of animal products.
Here is my summary of the amounts. The amounts are cals in 100g, mcg K in 100g and mcg K2 in 2000 calories of the food. Hope it makes sense.
Food 100g cal K2 K2 in 2000kcal
chicken 154 48 623
duck 183 45 492
goose 179 45 503
yolk 348 147 845
pork 123 61 992
beef 147 81 1102
chicken 147 87 1184
veal 146 97 1329
liver pate 299 49 328
C'bert/brie 362 35 193
cream 40% 373 40 214
milk,boiled 65 4 123
hard cheese 356 25 140
proces'd cheese 327 30 183
sour cream 10% 117 10 171
Edam 45% 354 30 169
butter 741 60 162
Corned beef 141 20 284
Salami 365 14 77
pork belly 469 8 34
beef rib 146 13 178
Ox tail 221 15 136
Other fats, offal, seafood and most meats contain none.
Lee April 30, 2009 9:25 AM"
end quoted material
I think you're not going to find the answer very satisfactory, but the truth is there is NOT a typical quantity of K2 in butter. It varies tremendously based on diet and soil conditions:
FWIW, at the end of that article there is a table, with citations, listing the type and source of K2 in various foods. It shows butter as 15 mcg/100g.
Butter oil is what i use when I am trying to reverse vascular calicifications and or improve osteopenia or porosis. We did do some testing on Kerry Gold butter ourselves and got real different values from the lots we bought. So I am not a big fan of theirs as I once was. Now we advocate Organic Valley who has been consistent
It's not a nutrient that the food companies really track. It probably varies depending on the time of year--I would expect to see more of it in the spring and far less in the fall and winter.
Conventional butter in Japan has 21 mcg/100g. (Kamao 2007)
K2 levels for seemingly all other foods EXCEPT butter are given in this article
If K2 levels have indeed been measured in grass-fed butter, I might be able to find out, as the above lab is down the street from my office!
This article appears to have your answer, although I can only access the abstract. I suspect the butter they test may be grass-fed, because of the nordic location. The couple studies that mentioned butter (which may be pastured or not) indicated low menaquinone levels, orders of magnitude below that of aged cheese.