I Have Chronic Severe Leg Cramps At Night That Disturb

I have chronic severe leg cramps at night that disturb my sleep, I had gastric by-pass surgery in 1996. These cramps started about 12 years ago but were few and far between. At that time my doctor started giving me B12 injections which seemed to help. I switched doctors about 5 years ago and she stopped the injections and said my B12 levels were good. The cramps started again about 6 months ago. Usually after I am very active here at the farm. Should I restart the B12 injections?