Hand and back Pain. Suggest further.

I have donated blood on May 25th and from next day pain started on Neck(One side one time and another side different time) and also near bone in back side of the hands(Left and right).So i did colestrol testing and it is normal. And Pain was continuting So end of June i have did whole body testing(Gold package which includes stress test as well) in Jehangir hospital and everything was normal except calcium...it was low.As i was telling pains on hand doctor told it might be gas trouble for you and given tablets for 10 days and calcium tablets for 3 months.And for some days Body was normal and again it started pain(cannot say exactly the pain it is something like zive zive) in left hand and back pain.And also heavy chest and some swelling type near bone below neck and side of the hand. And when i told same thing to another doctor who sits in my office she told might be D and B12 defecncy and given some takens for the same...Can you please suggest further.