Fig. 2

Comparison of percent bias of 25(OH)D Assays [7]. Comparison of % bias of Method Mean of 25(OH)D assays from NIST-assigned target values for DEQAS samples from 2012 to 2014 and 2015-2017. The error bars are ± SD of the % bias (n = 36). Adapted from C.Q. Burdette et al., J. AOAC Int., 100 (5), 1277-1287 (2017)