Dr. Amy Nett: This is a great question, I think, because there’s still so much research around vitamin K2. We haven’t talked about vitamin K too much here, so I’m just going to say that MK-7 and MK-4—oh, yeah, Chris has talked about this on one of the webinars—these are both forms of K2. There’s K1, which you’re going to get from plants. That’s a little bit different. The liver preferentially uses K1 for clotting factor. We’re talking more about K2, the MK-7 and MK-4, specifically, which is a slightly different compound. This is kind of nuanced. I would say we do recommend vitamin K2 supplementation in a variety of settings, and we generally don’t specify amounts of MK-4 versus MK-7, as you’ve explained, Justine, for at least three reasons that I can think of.
Number one, it’s a little bit difficult, given the available supplements on the market. There are options for K2. Some are strictly MK-7, some are strictly MK-4, but to really work out the nuances of the 100 to 400 micrograms of MK-7 versus 2,000 micrograms of MK-4, it’s going to be difficult somewhat. There are still limited options for good K2 supplements.
Secondly, from an ancestral perspective, because that’s really where we come from on nutrition, a sort of nutrient-dense diet, looking at it from an ancestral perspective. From that, such precise nutrient ratios are unlikely to have been a consistent feature. Our bodies are incredibly adaptable, and I think focusing on nutrients to this degree is probably more effort than is really needed. Most people aren’t just focusing on vitamin D and vitamin K. We’re taking a lot of different supplements when we’re going through that more therapeutic phase. So I don’t think I would worry about such precise nutrient intake because, again, when we were eating from this ancestral perspective, there was a rough idea of what these ratios looked like, but I don’t know that we can really take it down to such a fine level.
The third reason, I would say, is that research is ongoing. Some of the data has said that MK-7 is preferable, that it stays at therapeutic doses in the blood for longer, meaning it has a longer half-life. Some people have argued that MK-4 is synthetic. It’s often made from extract of tobacco as opposed to natural MK-4 and dairy from pastured cows. But still other studies have suggested more people are intolerant to MK-7 because it’s most often derived from soy. So people who have a severe soy sensitivity might react to MK-7. Other studies say that there might be more benefit to MK-4 for bone strength because one of the places we use K2 is for strengthening bones and preventing osteoporosis. All that to say research is ongoing. I don’t know exactly if we can pin it down and say specifically the exact ratio of MK-4 or MK-7 to vitamin D and which one is going to be of benefit.
And then the other thing I would think about is, depending on the clinical setting, we might actually be doing even higher doses of vitamin K2. You mentioned this specifically in the context of if someone is taking 1,000 IU of vitamin D, should they then be taking 5,000 micrograms of MK-4? Maybe, but the other thing you want to think about is, is this a patient who has cardiovascular disease risk factors? An older woman who has osteopenia or even osteoporosis? Some of those studies, I think specifically looking at osteoporosis and I think also cardiovascular disease treatment and prevention, are actually using doses as high as 30 or even 45 milligrams. Here you said 5,000 micrograms, but we’re talking up to 45 milligrams, so a pretty big dose variation. Vitamin K2 does not have a known toxicity that I’m aware of, so you have some flexibility in going up to higher doses. I think we need to keep our eye out on the research to figure out where we’re going to be going with vitamin K2 recommendations.
The take-home point from there, I would say, is make sure patients are getting enough vitamin K2 or getting some vitamin K2. We generally recommend K2 without significant K1 since the higher doses of K1 can be counterproductive. Right now we’re using the Thorne brand liquid K2. Those of you who use Emerson, you would have noticed that Emerson stopped carrying Thorne recently, so we know get a lot of our products from … I think it’s Natural Partners. They sell the Thorne brand products. They have the Thorne brand liquid K2, and we’ll probably be carrying that in the supplement store that Chris is setting up as well. That’s mostly what we’re using right now. We’re using a pretty wide range of dose variations. I will use something like 3 to 5 milligrams in lower risk patients, but again, I will go up to 30 to 45 milligrams of K2, and I’m not really differentiating specific ratios of MK-4 to MK-7. Hopefully that answered your question. I guess the answer there really is, I don’t know yet. I think we’re still learning, but stick with K2 over K1, and that’s the most important thing.