Hypercalcemia in Two Patients With Sarcoidosis and Mycobacterium avium intracellulare Not Mediated by Elevated Vitamin D Metabolites

Although hypercalcemia in granulomatous diseases has been attributed to be mediated by elevated vitamin D metabolites, there have been several case reports that documented normal values of active vitamin D metabolites. This report illustrates the regulatory feedback mechanisms of vitamin D synthesis and introduces the term “inappropriately normal” vitamin D metabolites levels in light of low levels of parathyroid hormone.