Time Intervals
A common cause of high B12 levels is the time interval between taking a supplement and a blood test. Ideally, you should not measure B12 levels in the blood within 10 days after an injection of this vitamin. During this period, the concentration is still high, which could lead to misleading results. Taking high-dose B12 supplements orally could also lead to the same effects. Ideally, the test should be implemented after 10 days, which is enough for the supplements to be absorbed by the body. [4]
