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1 µg/d of B12 p.o.a

Serum B12 rose to 121 pmol/L (164 pg/mL) (said to be normal) and hemoglobin stabilized at 10.7 g/ 100 mL

1 pint/d of fresh milk (≈1.5 µg of B12)b

Serum B12 maintained at 100 pmol/L (134 pg/mL)

Not specified

Seven fulfilled at least one criterion for tissue B12 deficiency

1 µg/d of B12 p.o.

Serum B12 rose to 64 pmol/L (87 pg/mL), well below normal; gastritis may have decreased absorption of any B12 inadvertently present in the food


Half had serum B12 values < 74 pmol/L (100 pg/mL)

0.07–0.25 µg/d of B12

Judged inadequate

0.3–0.65 µg/d of B12

Hematological responses seen but serum B12 ≤ 74 pmol/L (100 pg/mL) in all

Interpretation complicated by transfusions and intramuscular injections

c SD = standard deviation.

d NA = not available.

Possible Ancillary Method: Maintenance of a Serum B12Concentration That Is Consistent with a Normal Circulating MMA Value

Several investigators have urged the use of the serum MMA concentration as the most sensitive indicator of B12 status (Lindenbaum et al., 1990; Moelby et al., 1990; Savage et al., 1994b; Stabler et al., 1996). This indicator could not be used as the criterion for setting

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