I am new to this forum, have had Mirena for three years and getting it removed in a couple of days. In the past few months I've had a few episodes of neurological symptoms that felt pretty scary (tingling in hands and feet, heart palpitations, headaches, brain fogginess, mood swings, in addition to other things--diarrhea, lack of appetite, insomnia, generally feeling horrible).
I'm not jumping to conclusions about Mirena necessarily, but I'm wondering if there is any connection between Mirena and the body's ability to process B12 properly. I have been taking B12 supplements for five years, since I was diagnosed with a B12 deficiency. I didn't have a Mirena then, but I was on the pill. I gradually increased my dosage of the B12 because it became clear that a) I was highly dependent on the supplements--going off of them for more than two days led to fatigue and severe headaches, without fail, and being on B12 made these symptoms disappear completely; and b) taking more B12 made me feel better. So I've been taking 5000 mcg of B12 daily for the past two years and had been feeling great until a few months ago, when the old symptoms that I had way back when I was first diagnosed with a B12 deficiency started, even though I was taking supplements religiously. I went off of B12 for the purposes of going to a doctor, thinking I might get a more accurate blood test, because I was thinking that I wasn't absorbing enough B12, even with the supplements. Not taking B12 for five days made me feel the worst I have ever felt in my life--and this is the first time I've had the constellation of neurological symptoms discussed above. Went to the doctor, my serum B12 was HIGH, not low, though by the time I found that out I had been back on B12 supplements for a few days and the neurological symptoms had gone away. After I got the test results I stopped taking the B12 again, thinking that somehow I had convinced myself I needed it when in fact I didn't, given the test results. The exact same neurological symptoms started up again, in the exact same timeframe as the first time. My doctor was pretty flummoxed by this (and referred me to a neurologist), but needless to say, I have gone back on B12, and after doing some research, I've started taking "methyl B12" (which is the "active" and better form, supposedly). I've improved tremendously, even from where I was when I had been taking the normal B12 supplements regularly (though I am still getting Mirena removed to see what if any role that is playing and if I can stop taking B12 supplements once it's removed).
Long (I know, too long!) story short, I've since read that oral contraceptives can affect how the body deals with B12, and I'm wondering if my recent B12 issues are related to the Mirena. And after reading about so many people with neurological symptoms after being on the Mirena, I'm wondering if many women having neurological and MS-like symptoms (many of which overlap with symptoms of B12 deficiency) are having issues with B12 (even if there is no "actual" deficiency! The serum B12 test is not a very good test and doesn't tell you whether your body is able to effectively use the B12 in your body). Given my own total dependence on B12 supplements, even with my high serum B12 level (due to taking supplements for years), it seems that I am unable to properly use B12 for some reason and I wonder if hormonal birth control is involved somehow. Anyway, maybe women having neurological symptoms with/post-Mirena might try taking a supplement of methyl B12 to see what happens. (An intense reaction--chills, tingling sensations, anxiety--to an initial supplement of methyl B12 can be a sign that your body hasn't had enough of it and has adapted to the deficiency, hence, sudden surplus makes you feel weird at first. Lot of info about this on Phoenix Rising, a site for people with chronic fatigue syndrome, which for some people might be related to B12 issues. Obviously I've spent too much time on the internet researching B12 deficiency! My experience with my doctor on this has been unsatisfying. :/ )
Of course, it's totally possible that my issues have nothing to do with Mirena or hormonal birth control. But a B12 supplement is an easy thing to start, and if it can help anybody else then I figured it's worth posting about.