can b12 injections cause side effects Vitamin Effects: Risks of Excess Intake Oral vs. Intramuscular Vitamin B12

Oral versus intramuscular administration of vitamin B 12 for the treatment of patients with vitamin B 12 deficiency: A pragmatic, randomised, multicentre, non-inferiority clinical trial undertaken in the primary healthcare setting (Project OB12)

Consistent use and adherence to a healthy diet and exercise plan are important for optimal results

Reported dose-dependent limitation of weight and fat-mass gain, improved glucose tolerance and insulin sensitivity, reduced hyperinsulinemia, and improvements in steatosis and liver markers

These effects are typically mild and resolve within days

In 2025, scientists at University of California, San Francisco, reported that even older adults with B12 levels considered "normal" showed subtle signs of neurological decline

What results or benefits should I expect to see, and how soon