Some people report feeling increased energy and improved well-being within days of getting a B12 injection, but it may take a few days or weeks before your vitamin B12 levels and symptoms start to improve.
The frequency of Vitamin B12 shots depends on dosage and how well the body replenishes its vitamin stores. Some people may only need a shot every 7-10 days, while others may get good results with monthly injections.
Vitamin B12 supplements, such as tablets or capsules, can be effective in treating a deficiency, but they may not be as well absorbed as an injection. In some cases, people with gastrointestinal issues may not absorb Vitamin B12 effectively from oral supplements.
