Serum levels of free 1,25-dihydroxyvitamin D in vitamin D toxicity.
Pettifor JM, Bikle DD, Cavaleros M, Zachen D, Kamdar MC, Ross FP.
Ann Intern Med. 1995 Apr 1;122(7):511-3.
PMID: 7872586
CONCLUSIONS: Although the patients had normal or near-normal total 1,25-(OH)2D values, most patients had elevated free 1,25-(OH)2D levels. These findings suggest that elevated free 1,25-(OH)2D levels might play a role in the pathogenesis of hypercalcemia in vitamin D toxicity.