how long for vitamin b12 injection to take effect Fast Does a Shot Work? B12 INJECTION - Elite IV

Everyone processes nutrients at a slightly different pace

The vitamin is delivered into the fat layer just under the skin, often in the abdomen or thigh

If you experience severe pain, signs of infection (redness, warmth, swelling), or an allergic reaction (rash, itching, difficulty breathing), seek medical attention immediately

We order vitamin B12 and folate testing when a person with Down syndrome we are evaluating has symptoms described above, has a lab abnormality for which follow up testing of vitamin B12 and/or folate is indicated, or the person has a condition in which deficiency is common (e.g., celiac disease)