Is a b12 vitamin shot necessary?

Depends: If you are deficient in B12 and are unable to absorb the vitamin through oral intake, an injection would be appropriate. Even if you are deficient and have malabsorption, you may wish to try a sub lingual form of B12 supplement. It would be appropriate to discuss it with your doctor to see if you need B12 supplement and if you do, in what form. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Drink enough water daily, so that your urine is mostly colorless. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex.