[1] [2] While high-dose oral B12 supplements can be effective through passive diffusion, they are not routinely recommended for pernicious anaemia management in UK practice
Safety and Precautions for Vitamin B12 Injections Injections of vitamin B12 are usually safe and well-tolerated
It should be stored at room temperature and not frozen, and should be used within 28 days of first puncture
Vegans and vegetarians

Vitamin B12 injections deliver B12 deeply into the muscle or just under the skin, allowing it to bypass the digestive system and enter the bloodstream for rapid absorption. This route is especially helpful for people who cannot absorb B12 well from diet or oral supplements, including those with digestive disorders, certain medications, or longstanding deficiency. Clinical experience and clinical studies show that B12 injections are one of the most efficient ways to restore low B12 levels, often improving energy levels, mental clarity, and overall wellness. Many patients report more energy, better sleep, and improved mood after regular B12 supplementation, though results can vary and should always be guided by a healthcare provider. Where You Can Get B12 Injections There are several safe, reputable places to receive vitamin B12 injections, each with different levels of medical oversight and convenience. Primary care and specialist clinics Your primary care physician is the standard starting point to check B12 levels, diagnose deficiency with a blood test, and prescribe injections when appropriate. In these settings, injections are administered in the care teams office by nurses or other medical professionals, where patients can also consult healthcare providers for instructions and scheduling

Some people may have no symptoms at all, even with low B12 levels