are vitamin b12 injections shot Best Vitamin B12 Injection Site:

Common symptoms of Vitamin D and B12 deficiency include persistent fatigue, muscle weakness, bone pain, brain fog, tingling sensation in hands and feet, mood changes, hair fall, and frequent infections

Carbohydrate timing around AOD-9604 administration matters

But if you have pernicious anemia (that is caused by a B12 deficiency) or have any other trouble absorbing B12, injections might be a good idea for you, Warren says

But the thigh is the best option for people who experience significant nausea, prefer clear visibility of the injection, or have limited subcutaneous fat in the abdominal area

PMID: 27916823

The primary diagnostic test is a blood test Normal vitamin B12 levels typically range from 200 to 800 pg/mL