b12 injection vs oral Why get shots take B12 orally?, •B12 injections are more bioavailable Vitamin B-12 Injections Vs Oral

It is possible that compensatory mechanisms could develop that reduce efficacy with prolonged use

Other people who are at risk of having vitamin B12 deficiency include those who have had intestinal surgery, or who have gut diseases like Crohns disease or celiac disease

While these are population-level numbers, the principle applies to individuals as well: routine injection visits for non-deficient patients add up in copays, travel time, and appointment scheduling without delivering additional benefit

Common reasons include: Pernicious anemia , an autoimmune condition affecting intrinsic factor production Gastrointestinal disorders, such as Crohns disease or celiac disease Prolonged use of certain medications, like proton pump inhibitors Knowing these causes helps spot at-risk people

That's why it's important to let your doctor know if you have any of the following conditions before you're prescribed hydroxocobalamin: If you've had an allergic reaction to hydroxocobalamin or any other medicines in the past If you've been diagnosed with low levels of potassium If you have an irregular or fast heartbeat Once you've started taking hydroxocobalamin, you may have some side effects such as pain, swelling, or itchy skin at the point where the syringe was injected

A blood test tells you that, so you are treating a real, measured problem rather than guessing