OBJECTIVE We investigated whether supplementation of the active form of vitamin D (calcitriol) in recent-onset type 1 diabetes can protect beta-cell function evaluated by C-peptide and improve glycemic control assessed by A1C and insulin requirement. RESEARCH DESIGN AND METHODS Thirty-four subjects (aged 11-35 years, median 18 years) with recent-onset type 1 diabetes and high basal C-peptide ...

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Aberrant Hedgehog (Hh) signaling is characteristic of the embryonal subtype (ERMS) and of fusion-negative alveolar RMS. In the mouse, ERMS-like tumors can be induced by mutations in the Hh receptor Patched1 (Ptch). As in humans these tumors show increased Hh pathway activity. Here we demonstrate that the treatment with t...

A series of nonsecosteroidal vitamin D3 receptor (VDR) ligands with phenyl-pyrrolyl pentane skeleton were synthesized for cancer therapy. In contrast to 1α,25-dihydroxyvitamin D3 (Calcitriol), these VDR ligands exhibited anti-proliferative activity without inducing hypercalcemia. These compounds were evaluated for vitamin D3-agonistic ability and anti-proliferative activity in vitro. Among them...

Calcium and phosphorus exist in a delicate balance in the body, with bone playing a central role in maintaining whole-body calcium–phosphorus homeostasis. The balance of phosphorus and calcium in healthy individuals is maintained through the complex interplay between parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D3 (calcitriol). If serum calcium levels fall, PTH acts to increase renal rea...

BACKGROUND AND PURPOSE Chemokines play a critical role in the pathogenesis of asthma and facilitate the recruitment of inflammatory cells in the airways. Evidence now suggests that airway smooth muscle (ASM) may serve as a source of chemokines in inflamed airways. Although vitamin D has potent anti-inflammatory properties in vitro in some cell types, its effects on ASM cells remain unclear. Her...

BACKGROUND The regulatory mechanisms of parathyroid hormone (PTH) synthesis are complex, involving calcium, calcitriol, the calcium-sensing receptor (CaR) and the vitamin D receptor (VDR). In this study, the effects of calcium and calcitriol on the simultaneous expression of CaR and VDR mRNA and protein levels were assessed in parathyroid glands cultured in vitro. METHODS Parathyroid glands (...

Low vitamin D status is considered as a risk factor for breast cancer and has prognostic significance. Furthermore, vitamin D deficiency increases after adjuvant cancer therapy, which alters bone metabolism increasing the risk of osteoporosis. It is now postulated that vitamin D supplementation in breast cancer treatment delays the recurrence of cancer thereby extending survival. We evaluated t...

BACKGROUND Preclinical and clinical data have suggested that high-dose calcitriol (1,25-dihydroxycholecalciferol) has activity against prostate carcinoma. Pulse-dosed calcitriol and dexamethasone may maximize tolerability and efficacy. The authors examined the toxicity of pulse-dosed calcitriol with zoledronate and with the addition of dexamethasone at the time of disease progression. METHODS...

BACKGROUND Secondary hyperparathyroidism is a common complication in patients with chronic kidney disease and treatment with vitamin D analogues is a mainstay of therapy. Although oral calcitriol and alfacalcidol are used extensively in Canada, there is little published data comparing equal doses of these agents. OBJECTIVES To compare the effect of equal doses of oral calcitriol and alfacalci...

A normal vitamin D status is essential for human health. Vitamin D deficiency is a recognized risk factor for all-cause mortality in normal individuals and in chronic kidney disease (CKD) patients. The link between vitamin D deficiency and death is a defective activation of the vitamin D receptor (VDR) by 1,25-dihydroxyvitamin D (calcitriol, the vitamin D hormone) to induce/repress genes that m...