Vitamin B12 Dosage: What Is the Proper Daily Amount? Dr. Axe The Advantages of B12 Injections Versus Oral Supplements: Shawn Veiseh, M.D.: Family Medicine I often get asked if B12 is just a concern for vegans. The answer? Not at all. Even if you eat meat or dairy, there's no guarantee you're absorbing enough, especially as People love to bring up B12 like it's a reason to eat meat. But here's the irony Even meat eaters can be deficient in B12. That's because B12 comes from bacteria in Vitamin B12 in Pregnancy: What You Need to Know NaturoBest The B12 in meat is from supplements given to the cows.so why not just take the supplement directly : r vegan