 [ Symptoms ] can vitamin b12 be used for weight control i took heavy does of steriods for mirgraines administered by a family doctor is pa at the time i was 44 years of age i left shortly after receiving the medication to go to california to visit my family i gained huge amounts of weight each day by the time i got back from california i had gained nearly 100 pounds i am now 69 and frustrated & asshamed of how heavry i am i have exercised and dieted on chicken fruits and vegetables could vitamin b12 injections help [ Disease ] no there is no correlation between vitamin b12 and weight changes either causing weight gain or facilitating weight loss