I have a sort of similar question to a previous one, I live in the UK and the RDA of vitamin K is 1 mcg per kg body weight, so if you are 70 kg you need 70 mcg vitamin k, but I buy my supplements from america and the DV is 80 mcg but you say on this site the AI is 120 mcg, how much vitamin k should I aim for, I obviously follow your recommendations on vitamin D.Thank you everyone.
So I have answered different questions about Vitamin K several times. After reading yours I decided to actually read the link that goes to the National Academy of Sciences. I then tried to stay awake while reading it! So apparently they have not set an “upper” level of intake because there is no research that proves going beyond a certain limit is harmful. They did set a minimum level but it really looks like anywhere from 80-120 is good hence why you are getting different recommendations from different organizations. Having said that, Dr. Cannell once wrote in a blog the following while he was discussing Vitamin K1 and K2. He made the statement “One cup of cooked kale has more than 1,000 mcg of vitamin K1.” “A cup of cooked spinach has more than 800 mcg.” “And a cup of turnip greens has more than 500 mcg.” This then begs the question if these things have so much in them then is the 80-120 really a good set point. No one knows. That same blog also covered the subject that humans do convert K1 into K2. So the “jury” is still out at this time whether or not if you ingest enough K1 will you then supply yourself with enough K2. So sometimes without enough information we just need to do the best we can and also hope for the best. Dr. Cannell also said “However, as far as getting enough vitamin K2, the best thing to do is eat your greens.”