I did see a web page that says excess B12 can cause loss of calcium, which in turn can raise blood pressure. I don't recall seeing that warning here, with recommendations of 5,000mcg of B12 being safe to take. I am on blood pressure medication (that works very well for me) & hadn't checked it in some time. I discovered that my BP is at levels like it was before I started the medication, and I'm taking just 2,000 mcg daily. I plan to cut most of my supplements tomorrow, to see if that is B12, or a different one. I'm also on gabapentin, which in more rare cases, can elevate blood pressure, and that will have to be changed if cutting the supplements doesn't work. For proof of my statement, check this page under HYPERTENSION: http://www.livestrong.com/article/32...lood-pressure/