Diagnostic Accuracy of Holotranscobalamin, Vitamin B12, Methylmalonic Acid, and Homocysteine in Detecting B12 Deficiency in a Large, Mixed Patient Population

Table 4

Diagnostic accuracies of the different markers for detecting low B12 (4cB12< -0.5 and >-1.5) in men and women over or under 50 years.

Marker ( whole group) ( with low 4cB12)	Women () ()	Men () ()	<50 years () ()	≥50 years () ()	Women, <50 years () ()	Women, ≥50 years () ()	Men, <50 years () ()	Men, ≥50 years () ()
HoloTC	0.919	0.913	0.919	0.918	0.923	0.925	0.915	0.910
B12	0.898	0.91	0.923	0.893	0.918	0.887	0.936	0.899
MMA	0.913	0.902	0.921	0.899^†	0.925	0.905^†	0.911	0.895
Hcy	0.783^‡	0.831^‡	0.771^‡	0.799^‡	0.773^‡	0.793^‡	0.855^‡	0.817^‡

Significant difference between the AUC of B12 and HoloTC ().^†Significant difference between HoloTC and MMA (). ^‡Significant difference between Hcy and all other markers (). The difference in the AUC of B12 and MMA was not significant in either subgroup ( in women; in women ≥50 years).