How to inject B12: https://youtu.be/miKARc4BABA
As a vegan, whether you’re practicing raw, 80/10/10, raw till 4, starch solution or fruitarian, you should supplement vitamin B12. The most common ways of taking B12 is orally or by injections. Injections are only necessary if there is a problem with absorbing B12. What is important is that once a year you get medically tested for B12 deficiency. If there is an issue injections are the way to go.
Vitamin B12 deficiency can happen if you have certain conditions, such as:
Atrophic gastritis, in which your stomach lining has thinned
Pernicious anemia, which makes it hard for your body to absorb vitamin B12
Surgery that removed part of your stomach or small intestine, including weight loss surgery
Conditions affecting the small intestine, such as Crohn’s disease, celiac disease, bacterial growth, or a parasite
Immune system disorders, such as Graves’ disease or lupus
Long-term use of acid-reducing drugs
You can also get vitamin B12 deficiency if you’re a vegan (meaning you don’t eat any animal products, including meat, milk, cheese, and eggs) or a vegetarian who doesn’t eat enough eggs or dairy products to meet your vitamin B12 needs.
Babies born to mothers who are vegetarians may also not get enough vitamin B12.