As far as K2 is concerned, my understanding is that MK-4 is the most easily used form when naturally occurring in food, but the only MK-4 I’ve found in supplements is synthetic. I try to avoid synthetic nutrients if possible, and I’ve read that synthetic MK-4 is used differently and less efficiently in the body than when it is consumed in whole food form. MK-7 supplements derived from natto seem like the best choice to me, but the amounts are so much lower in supplements. I guess I’m confused about the dosage of MK-7 versus MK-4 in supplement form, especially when trying to overcome a deficiency. Any thoughts on the subject? I see Chris sells the Thorne brand that has D and K2 that has the synthetic MK-4 in it.

Laura Schoenfeld: Yes, the supplemental form of MK-4 is always going to be synthetic. I’m not exactly why the reason for that is, but I’ve never seen a “naturally occurring” MK-4 be used as a supplement. MK-7 is natural, and it’s derived from natto, so if you feel that the natural form is optimal for whatever reason—and you’re more than welcome to feel that way—then, yeah, the MK-7 is going to be a better choice.

The reason that the dosage is different for these two forms is because the MK-7 has a much longer half-life in the body than the MK-4 version does. Basically what that means is that the MK-7 lasts a lot longer in the body than the MK-4 does. I don’t remember the exact difference as far as the number of hours that MK-7 will hang around versus MK-4, but that just means that the body has more time to use the MK-7 and thus you don’t need as much, whereas the MK-4 is going to get either converted into something else or excreted much faster than the MK-7, so the more you take, the easier it is for your body to get what it needs out of it.

The dosage recommendation for MK-7 usually is around 100 to 200 micrograms. Sometimes they come in 90 micrograms, not that big of a deal, but I’d say 100 to 200 is usually optimal. Then MK-4, the dosage is going to be closer to a milligram, so 1,000 micrograms. You can go higher than that. There’s no known risk of overdosing on vitamin K2, but if you feel like the MK-7 is a better form to use, then, yeah, definitely 100 to 200 micrograms should be plenty. The only reason that that might not be a good choice for someone is if they’re, again, allergic to soy, and then the MK-4 is going to be the better choice for them in that situation. That’s where you have to make a judgment call. Even if MK-4 is synthetic, is it worth avoiding entirely for someone who’s allergic to soy, or is it the best option that you have? You have to make that decision. I’d say my personal opinion is that the synthetic MK-4 is better than nothing. Hopefully that answers that question as to why the dosages are so different.