There are two types of vitamin B12 injections:
If your vitamin B12 deficiency is caused by a lack of the vitamin in your diet, on the other hand, you may be prescribed vitamin B12 tablets to take every day between meals, explains the NHS.
How to to top up the vitamin through your diet
Vitamin B12 is naturally found in meat, oily fish, milk and other dairy products, and eggs
People who find it difficult to get enough vitamin B12 in their diets, such as those following a vegan diet, may need vitamin B12 tablets for life, notes the NHS.