Pharmacokinetics of 1α,25-Dihydroxyvitamin D<sub>3</sub> in Normal Mice after Systemic Exposure to Effective and Safe Antitumor Doses

Abstract

These results demonstrate diurnal variation in baseline plasma 1,25-D(3) concentrations in mice. Plasma 1,25-D(3) PK in mice receiving doses that are effective in slowing tumor growth, inducing cell cycle arrest and apoptosis, and potentiating taxanes and platinum analogue antitumor activity are at least 5-10 times higher than those easily achieved and nontoxic in patients receiving high-dose intermittent oral therapy.