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The active hormonal form of vitamin D₃, 1,25-dihydroxyvitamin D₃[1,25(OH), which regulates cellular replication and function in many tissues and has a role in bone and calcium homeostasis, acts through a hormone receptor homologous with other steroid and thyroid hormone receptors. A 1,25(OH)₂D₃-responsive element (VDRE), which is within the promoter for osteocalcin [a bone protein induced by 1,25(OH)₂D₃] is unresponsive to other steroid hormones, can function in a heterologous promoter, and contains a doubly palindromic DNA sequence (TTGGTGACTCACCGGGTGAAC; -513 to -493 bp), with nucleotide sequence homology to other hormone responsive elements. The potent glucocorticoid repression of 1,25(OH)₂D₃ induction and of basal activity of this promoter acts through a region between -196 and +34 bp, distinct from the VDRE.