CarlsonVitamin K2, MK-4 (Menatetrenone), Vitamin K Supplement, Bone & Heart Health, K2 Vitamin, Soy-free, 60 capsules

I purchased this product here and was happy with it. It seems MK-4 exists in certain mammalian tissues, with some organs having higher concentrations than others. Experiments with radio-labeled K-1 suggests that it can be converted into MK-4, but probably not at the therapeutic level individuals might seek.The source in supplements seems to be entirely synthetic for MK-4(from a tobacco product I read), because sourcing animal products for it for extraction would be out of sight expensive. The highest food source seems to be "Fois Gras" and has 369 mcg in 100 grams, etc. Geese seem to consume the type of grass and consequently K-1 that their system can convert to Mk-4.MK-9 seems exist in certain cheeses and has a very long half-life.Mk-7 might have a three day half-life it is claimed.MK-4 is said to be prescription in Japan for osteoporosis and typically given at 45 mg a day, in three 15 mg doses. Taking it with oil or fat containing meals seems to have a huge impact on absorption and consequentially utilization.I ordered two shippings of "two month supplies" at the just mentioned dosage, from a different than Amazon vendor, after ordering and partially consuming this Carlson product.I just discovered that Amazon now has vendors, including itself or Prime vendors, that carry the 15 mg/90 capsule bottles, which would be the Japanese monthly dosage for osteoporosis therapeutics. The source, brand, bottler, or whatever is called "Complementary Prescriptions" and can be located with a search on Amazon. The bulk manufacturer is probably based in China, though this isn't documented for the above product, there does seem to be MK-4 manufacturing sources in China, (...and since it isn't stated as being based elsewhere...).edit: In Japan the supplier is "Eisai" who apparently has a patent from the Ministry of Japan. MK-4 is sold in Japan and across Asia under the brand name Glakay.

Quick shipping. Very satisfied.

good

My people seam to think it works well .

I'm glad they make this MK-4 version. MK-7 gives me horrible insomnia, even though other people do just fine on it.

My wife and I have been taking a capsule daily for several months now.I have noticed vague differences that may only be psychological or related to something else.Nonetheless, I feel good about taking this product based on the burgeoning research that is taking place regarding Vitamin K2 (the MK4 version has had the most studies done at this point). Cause and effect points to K2 superior to our previous routine of taking calcium and Vitamin D. We have stopped taking calcium (we eat foods that have plenty of calcium) and are now taking D and K2. Do some research and one will find that K2 is superior regarding bone building/bone loss prevention along with preventing calcification of arteries, heart tissue/other organ tissues vs. the accepted, conventional calcium supplementation. There are also other suspected benefits being investigated.

I took this form of K2 (MK7, I copied and pasted from my review for an MK7) for about seven months last year, in an attempt to improve the condition of my teeth. I did a bit of research into vitamin K and after reading many reviews, I decided to try MK7 after using Life Extension Super K for 1-2 months and not seeing much difference. Since the reviews for MK7 and other MK7 versions were so good, I thought everything would be great and kept reordering MK7 without worry.Seven months later, my teeth were horribly WORSE than before. I had developed a huge cavity in those few months that wasn't there before, my teeth were turning brown all along the inner edges, and one of my molars had a chunk of tooth just chip off on its own, on the side of the tooth. I hadn't really paid much attention to my teeth since I thought the MK7 would be taking care of them for me (dumb, yes I know). I never experienced that 'smoothness' on my teeth people always mentioned when taking vitamin K.I freaked out and started researching in earnest, everything I could, and why/how people's teeth were improving on vitamin K. I read Weston A Price, the entire website. I knew food sources of vitamin K + cod liver oil were not enough to rescue my teeth, especially the one huge cavity that started to be painful (definitely a root canal waiting to happen), and then I came across one article on Marks Daily Apple that discussed one woman's experience in saving her teeth with vitamin K, specifically MK4, NOT MK7.After reading that article I immediately ordered Carlson's MK4, which is 5mg per capsule, and started taking three a day, along with the Cure Your Tooth Decay book's emergency protocol of cod liver oil three times a day. The difference in my teeth has been incredible. The huge cavity I have has shrunk, and is now a light brown instead of black, doesn't cause me anymore pain, and all the brown along the inner edges of my teeth have faded away. My teeth are the brightest white they've ever been, and when I run my tongue along them, they are all smooth and clean. Before, when I would floss, the floss would rip and get caught on all kinds of jagged edges between my teeth but not anymore. It's been about 3 months on MK4 but the difference it has made in my teeth is really staggering.One thing I noticed on the MK4 is that I didn't need to take any vitamin D supplements at all, the vitamin K seems to 'magnify' or multiply what little you get from the sun so I would get terrible headaches and pains when taking both D + K, which disappeared when I stopped the vitamin D. I still get some vit.D from the cod liver oil, and it seems to be enough. My theory is that too much vitamin D without a proper vitamin K to balance/utilize it can really screw you up, and I firmly believe MK7 is NOT the right vitamin K to be taking.I also tried Thorne's MK4 drops, both sublingually and transdermally (a la Ray Peat), and it did not seem to be as effective as taking Carlson's orally, at least for me.update June 2017I am still taking this, but alternate between Carlson's and Thorne MK4 drops (taken orally). I have also added a high dose vitamin A (NOW foods 25,000 from fish oil) to balance out the vitamin D I am taking (5000iu every other day), financially I can't always buy the fermented CLO, which if taken 3 times a day is approx 30,000iu vitamin A (retinol forms not beta carotene). I learned that the headaches I would get were from an imbalance in the fat soluble vitamins (A, D, K) and perhaps occasional oxalate dumping - BUT I'm not an expert. I just am happy to have smooth teeth. I still strongly believe MK7 is not the correct form of vitamin K to take and believe my teeth really suffered during the time I took it. I've read articles that mention MK7 is much cheaper to produce than MK4 so manufacturers stand to gain much more profit from it. Also, Weston A Price noticed the 'X-factor' only when humans consumed animal by-products and not plant products, the former being sources of MK4 and the latter MK7. I don't doubt the health benefits of MK7 but I don't think it affects the bone/tooth structure the way MK4 does.