[History of the development of new vitamin D analogs for the treatment of renal failure, and future aspects].

In 1981, Suda and colleagues reported the new activity of calcitriol namely its ability to differentiate the myeloid leukemia cells into monocyte-macrophages. Several companies and organic chemists initiated the synthesis of vitamin D analogs with the aim to separate the calcemic actions of calcitriol from its actions on regulating the cell growth and differentiation. The group of Chugai company succeeded in marketing OCT, Oxarol, as a therapeutic agent for secondary hyperparathyroidism and psoriasis, and Leo company, MC903, Dovonex, as a drug for psoriasis. The work on OCT and MC903 vigorously stimulated research world-wide in the development of vitamin D analogs into pharmaceutical products. More new impressive vitamin D analogs are being developed. I am convinced that various vitamin D analogs will become highly effective therapeutic agents at the clinical level in the new century, and also that a new theory on the mechanism of vitamin D action will be generated.