This study investigated the effects of intraspecimen variations in tissue mineral density (TMD) on the apparent-level stiffness of human trabecular bone. High-resolution finite element (FE) models were created for each of 12 human trabecular bone specimens, using both microcomputed tomography (μCT) and “gold-standard” synchrotron radiation μCT (SRμCT) data. Our results confirm that incorporating TMD spatial variation reduces the calculated apparent stiffness compared to homogeneous TMD models. This effect exists for both μCT- and SRμCT-based FE models, but is exaggerated in μCT-based models. This study provides a direct comparison of μCT to SRμCT data and is thereby able to conclude that the influence of including TMD heterogeneity is overestimated in μCT-based models.