My rheumatologist recently discovered I am vitamin B-12 deficient. She said
it can cause pins and needles feelings. I just read up on it and found this from a list of 7 Symptoms of B-12 Deficiency:
2. Pins and Needles
It’s very common to experience pins and needles if you sit cross-legged for far too long. However, pins and needles (or the feeling of numbness) throughout the body when you haven’t compressed any part of your body, can indicate a B12 issue. Numbness or the feeling of electric shock waves can be the result of nerve damage in B12 deficient patients. Nerve issues in the body can be traced back to low oxygen levels, due to poor red blood cell production, which the B12 vitamin largely affects.