It was Christmas week 1990 in Oakland. Steven Bloom was wandering through The Lot, that timeless gathering of hippies that springs up in the parking lot before every Grateful Dead concert, when a Deadhead handed him a yellow flyer.
Because of the general safety of the vitamin, upper limits for normal intake do not exist. If your blood values for the vitamin fall below a range of 170 to 250 picograms per milliliter, you may develop a B12 deficiency.
Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your health care provider. Results are given in nanograms per milliliter (ng/mL). A normal range for vitamin B12 is 190 to 900 ng/mL.f the test is done on your blood plasma, a normal range for folate is 2 to 10 ng/mL. If the test is done on red blood cells, a normal range is 140 to 960 ng/mL. If your folate results are low, it may mean you have: A diet that doesn't provide enough folate.