I'm a little confused about B12. I originally started taking Jarrow 5000mcg B12 every day for some symptoms in my feet - stinging in the big toes, burning, minor tingling, unusual sweating, and painless muscles twitches that later spread to my calves. I just checked my Amazon order history and I took 5000mcg of B12 for 180 days.

About 1.5-2 months after the problems with my feet started, I developed severe pain in my shoulder - mostly the right one, but also somewhat in the left. The pain is an intense, deep ache somewhere between sharp and dull. Reminds me of a toothache. It's sometimes felt along the upper backs of my shoulders kind of along the scapula, in the clavicle area (above and below the collarbone), and where the shoulder meets the arm. I also get intense stabbing pains at the base of my neck around where the inner end of the collarbone is. I've noticed that there's also some painless, quiet clicking noises when I move my (right) shoulder, and I seem to have a lot of crepitus in my neck, although it only "crunches" when I look upward.

The doctors have been unable to successfully diagnose and treat both the feet and shoulder issues. I've just been told that my shoulders are inflamed. One doctor said I had a shoulder impingement, another said bursitis, etc. I've tried oral steroids (made me extremely ill), a cortisone shot to the shoulder bursa (did nothing), physical therapy, chiropractors, ice packs, heating pads, Epsom salts, and painkillers. Stretching helps - sometimes if I try to shrug my shoulder and experience a ton of pain, I'll leave my desk at work to go do some stretches in the hallway. If I can force my way through the pain and do the stretches, it seems like things loosen up and the pain will lessen a little. But doing computer work at my desk seems to inevitably lead to things tightening up and getting painful again, even though I try to be mindful of my posture.

I've come to realize that when I take my B12 pill, my shoulder pain is basically gone. There may be a twinge here and there, but overall I feel great, and my range of motion returns to normal. When the pain is at its worst it's hard to lift my arm up, especially when it's out at my side, and shrugging is veeeery painful. However, as soon as I stop taking my B12 I'm back to square one within a few days.

The issues with my feet have mostly cleared up, but I still have painless muscle twitches in my lower legs mostly, occasionally in my feet. FYI, my B12 level was a little under 500 when I originally got it tested back in April 2013.

Why don't I just keep taking my B12 every day, you ask? Well, unfortunately it causes some side effects. I get VERY short of breath and my heart starts racing within a few days. I do have some of Jarrow's B-Right which has a much, much lower dose of B12 in it, but that low dose doesn't affect my pain much. My body just can't seem to handle 5000mcg daily. I mean, it works great for the pain, but the shortness of breath is just brutal. I may try cutting the dose in half or taking it every other day. Or maybe I'll buy some 1000mcg pills. I'm not sure what to do.

I don't understand why the megadose of B12 seems to perform even better than a prescription painkiller like Naproxen, and my research hasn't turned up much. Does B12 just have a big anti-inflammatory effect? Is a lack of B12 the cause of my pain in the first place? The reason why I'm so curious is that this might help me get to an actual diagnosis, which I'm desparate for. Shoulder pain can have SO many causes. But if a high dose of B12 can kick that pain in the butt, it seems to me that it's unlikely I have something like a herniated disc in my neck or a rotator cuff tear, you know?