side effects of too much vitamin b12 injections Are Shots Safe? Royal Palm Beach Medical Group Side Effects of Too Much

The MHRA advises checking B12 levels in patients taking metformin who develop symptoms of deficiency or have risk factors, with periodic monitoring in at-risk patients

According to the 2025 meta-analysis by Alfalasi and colleagues, sublingual B12 showed an approximate 199% mean increase in serum B12 compared to approximately 307% for intramuscular injections

An incorrectly administered intramuscular injection can lead to severe pain, nerve damage, and long-term health complications

Each vitamin plays a unique and irreplaceable role in the body: Vitamin B6 : This vitamin is essential for protein metabolism, the production of neurotransmitters such as serotonin and dopamine, and the synthesis of hemoglobin , which is crucial for oxygen transport in the blood

For individuals with atrophic gastritis, pernicious anaemia, or those taking proton pump inhibitors , food-bound B12 absorption is already compromised