Cyanacobalamin? Has b12 + b9 + b3?

Dear, What is simple difference between cyanacobalamin injection v/s Methylcobalamin injection? Both are B12 I believe so? Then, Which of above B12 form is better quality for beta thalassemia minor patient to take every 3 months? Can Methylcobalamin injection will do better than cyanacobalamin? Should beta thalassemia minor patient take pure cyanacobalamin or should we take combo injection with b6 and b9? Vitcofol has B12 + b9 + b3? I earlier took cyanacobalamin alone for 5 yrs in foreign. Off late I took Vitcofol which is more painful than cyanacobalamin, as India does not have pure cyanacobalamin injection here. We always get combos with something else. India manufacturers pure cyanacobalamin but only export. Please explain the best. Sincerely, Thank you.