Vitamin B12 Benefits and Best Sources 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, theres no guarantee youre absorbing enough, especially as you age or if youre on B12 doesn't magically come from animals, it's made by bacteria in soil. Farmed animals are literally injected with B12 these days because they don't get it from food anymore. We scrub and