The only thing positive I can say about this vitamin is that because of the crazy side effects I've experienced from taking it, I now know that I must do extensive research (i.e. the good, bad and ugly)on every supplement I take before I buy it; whereas before, I only focused on the positive benefits of a supplement especially if some Guru promoted its claim to fame or it gets high reviewer ratings here on Amazon. On day 3 of taking this supplement, I begin to have scary heart palpitations which is something I have never had in my entire life of being a generally healthy person. At first I thought it was just really bad heartburn or some indigestion issues since I usually gobble my breakfast down before heading to work. However, the more I took this vitamin, the more frequent the heart palpitations would surface. But get this, not only did I have heart palpitations, but it also seemed as though the pills caused my brain to misfire or something. I really wish I could find the right words to describe what was going on with my mind. All I can do is give you an example by sharing that one day while I was working with a student in my office going over some details of an assignment with him, he asked me why I kept on saying the same thing and was I alright? He said that I went over the same bullet point 3 times in a row. He said I kept saying the same thing over and over as if it were my first time saying it. While taking the pills, I felt I was off, but not to the degree he would notice. I was very embarrassed and scared because I thought I was losing my mind. Taking this stuff resulted in my brain becoming very foggy, a bit discombobulated, sluggish and my behavior was filled with unnecessary redundancy. I knew something wasn't right with me, but I didn't know it was that bad until the student shared what he observed about my behavior. I really thought I was losing my mind. It was sooooooo scary because I am in my late 30's so I couldn't understand why this was happening to me. Not one time did it cross my mind that this vitamin could be affecting my life to this degree. I began to take the Mk-7 and D3 at the same time so in all honesty, I thought I was taking too much D3 since it was my first time ever taking it and I started out with a high dose of 5,000 IU's. I stopped taking them both and thankfully my right mind returned and I didn't experience any more heart issues. But I really wanted to know what caused those issues so I slowly re-introduced D3 back into my regimen at 1,000 and 2,000 IU's. I didn't have any issues with the D3, but as soon as I resumed taking the MK-7, my brain and heart started having the same issues again so I immediately threw the MK-7 out of my house, thus out of my life for good! This is absolutely one of those vitamins that you cannot play around with. I know they say consult with your physician before taking anything and we normally don't do that, but this is definitely one of those vitamins where you must do just that! In fact, I wouldn't take this vitamin unless I was under the care of a wholistic doctor because most regular doctors won't know much about this vitamin let alone its effects, unless they personally advise you to take it. I know everyone is different and others taking it may not have these kind of side effects, but I would never recommend this vitamin to anyone because it seemed to do more harm than good for me. If you do decide to take it, please be very cautious and know that you've been warned..... Also, many (not all, but many) of the 4 and 5 star reviews of this product rate this product based on what they believe, heard, or have read it is supposed to do in terms of the health benefits. That's why I tried it. Sometimes we just take supplements because we read about how good its suppose to be for you or some credible person said we should take this, that, and the other. It is not easy to test the efficacy of this vitamin. As far as I know, it is not like Iron or D3 where you can readily or easily get tested to see whether or not you are deficient in this vitamin. I buy lots of supplements and I only rate a few. That is because if I don't know for a fact that a product is actually working (whether for me or against me), I won't rate it at all because with many supplements it's hard to know if they really work or not. Pointing out all the stuff that it is supposed to do is a useless review. Nonetheless, by a process of deductive reasoning, you do know when something is bad for you and this product was a living nightmare for me. After taking this vitamin, I know now why my beloved and dearly departed grandmother used to say, "thank God everyday when you wake up and you are clothed in your right mind and have a good body to go with it." I am soooooo very grateful that I am now feeling like myself again, and after my horrific experience, I never want to see this vitamin again