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Normal value ranges for vitamin B12 vary slightly among different laboratories and can range anywhere between 200 to 900 pg/mL. The general consensus is values less than 200 pg/mL constitute a B12 deficiency.ormal value ranges for vitamin B12 vary slightly among different laboratories and can range anywhere between 200 to 900 pg/mL. The general consensus is values less than 200 pg/mL constitute a B12 deficiency.
The US RDA minimum for Vitamin B12 is 2.4 mcg per day for adults, and 2.8 mcg for pregnant or nursing women. More recent studies put the ideal intake at 4-7 mcg per day. The trouble is our bodies don't absorb all of the B12 we take, and there's kind of a cap on how much we absorb at one time.