Bone marrow and serum concentrations of 25-hydroxyvitamin D, 24,25-dihydroxyvitamin D, and 1 alpha,25-dihydroxyvitamin D in patients with leukemia and normal subjects.

Concentrations of 25-hydroxyvitamin D (25-OH-D), 24,25-dihydroxyvitamin D [24,25(OH)2D], and 1 alpha,25-dihydroxyvitamin D [1,25(OH)2D] in bone marrow and serum of patients with leukemia and normal subjects were assayed. There were highly significant correlations between the bone marrow and serum concentrations of the respective vitamin D metabolites. Especially, the concentrations of 25-OH-D and 1,25(OH)2D in the bone marrow gave very similar values to those in serum. This is a big advantage in controlling the bone marrow levels of vitamin D metabolites in patients with leukemia, because doctors can calculate the bone marrow levels from the serum levels of the respective vitamin D metabolites without bone marrow aspiration. When 1 alpha-hydroxyvitamin D3 (1 alpha-OH-D3) was administered orally to eight patients with leukemia, clinical conditions were improved in seven patients: four complete remissions (CR), one partial response (PR), and two minor responses (MR) without severe hypercalcemia. The results suggest that the therapy with 1 alpha-OH-D3 is fairly effective for curing human leukemia although it is not dramatic.