This page covers both, with the oral route first
First time I have ever been to a place like this always thought it was just for women
When youre deficient in vitamin B12, your mood and overall mental health may suffer
Because they give a slower, more gradual release than intravenous injections, subcutaneous injections are frequently used as a way to administer both vaccines and medications (for instance, type I diabetics often use this type of injection to administer insulin.)
The most common cause of vitamin B12 deficiency in the UK is pernicious anaemia, which is not related to your diet
Never discontinue B12 injections without medical advice, even if you feel completely well, as deficiency can recur and cause irreversible neurological damage if left untreated