can b12 injections cause nausea Are Shots Safe? Royal Palm Beach Medical Group Sublingual B12 vs. B12 Injections:

This is an elective wellness service not intended to diagnose or treat deficiency

Additional risk factors include: Chronic kidney disease : Reduced renal clearance may impair B12 excretion Liver disease : Hepatic dysfunction can disrupt B12 metabolism and storage Myeloproliferative disorders : Certain blood cancers increase B12-binding proteins Concurrent medication use : Some drugs may interact with B12 metabolism, including metformin, proton pump inhibitors, and H2 antagonists Patients with these conditions should have B12 supplementation carefully monitored by their healthcare team

It is important to note that all current evidence derives from in vitro cellular models and in vivo animal studies, and no human clinical trials have been conducted as of February 2026

When to Consider Vitamin B12 Injections If You Have a Deficiency : People who have been diagnosed with a vitamin B12 deficiency, especially those with underlying health conditions that affect absorption, may benefit from the rapid absorption and higher bioavailability offered by injections