The skin is the only tissue yet known in which the complete ultraviolet-B (UV-B)-induced pathway from 7-dehydrocholesterol to hormonally active calcitriol (1alpha,25-dihydroxyvitamin D(3)) occurs under physiological conditions. Epidermal synthesis of calcitriol could be of fundamental relevance because calcitriol regulates important cellular functions in keratinocytes and immunocompetent cells....

Calcitriol (1,25-dihydroxyvitamin D(3)), the hormonally active form of vitamin D, exerts growth inhibitory and prodifferentiating effects on many malignant cells and retards tumor growth in animal models. Calcitriol is being evaluated as an anticancer agent in several human cancers. The mechanisms underlying the anticancer effects of calcitriol include inhibition of cell proliferation, stimulat...

Patients with renal insufficiency develop secondary hyperparathyroidism. Monotherapy with active vitamin D or calcimimetics ameliorates secondary hyperparathyroidism. We compared kidney damage in subtotally nephrectomized (SNX) rats treated with active vitamin D (calcitriol) or the calcimimetic R-568. Male Sprague-Dawley SNX and sham-operated (sham-op) rats were randomized into the following tr...

BACKGROUND Prophylactic administration of calcitriol has been suggested to mitigate the risk of hypocalcemia after parathyroidectomy. The effect of calcitriol on postoperative serum ionized calcium concentrations has not been evaluated in dogs after parathyroidectomy. HYPOTHESIS/OBJECTIVES To determine the effect of prophylactic calcitriol administration on postoperative serum ionized calcium...

BACKGROUND The purpose of this study was to determine the effectiveness of oral calcium plus vitamin D supplementation and to compare the effects of cholecalciferol versus calcitriol treatments on postoperative hypocalcemia. METHODS After total thyroidectomy with central neck dissection, 306 patients were divided into 4 groups according to "routine use versus on-demand use" and "cholecalcifer...

While 1,25 dihydroxycholecalciferol (calcitriol) is best recognized for its effects on bone and mineral metabolism, epidemiological data indicate that low vitamin D levels may play a role in the genesis and progression of breast, lung, colorectal and prostate cancer, as well as malignant lymphoma and melanoma. Calcitriol has strong antiproliferative effects in prostate, breast, colorectal, head...

in mammals, phosphocalcic and bone metabolisms are mainly regulated by parathyroid hormone, parathyroid hormone-related peptide (pthrp) and 1α,25-dihydroxyvitamin d or calcitriol. in camels, circulating levels of calcitriol are 10 times higher than those determined in other ruminants and further increase during early lactation. calcitriol and parathyroid-related peptide stimulate intestinal abs...

There is no established therapeutic regimen for treatment of hypoparathyroidism during pregnancy. This is due particularly to uncertainty about the use of vitamin D or its analogues, as in animal experiments teratogenic side-effects have been reported. Nevertheless, vitamin D or its analogues are required to control tetany predisposing to abortion and preterm labour. We herein report the course...

The Janus kinase (JAK)1 and JAK2 inhibitor, ruxolitinib, and the active form of vitamin D (calcitriol) were previously reported to possess anticancer effects in breast cancer. The present study investigated the combined effects of ruxolitinib and calcitriol on an estrogen receptor (ER)‑positive, human epidermal growth factor receptor 2 (HER2)‑positive, breast cancer cell line. The ER and HER2‑p...

Hyperphosphatemia, calcitriol deficiency, and secondary hyperparathyroidism (SHPT) are common complications of chronic kidney disease (CKD). Fibroblast growth factor-23 (FGF-23) is a novel phosphaturic hormone that also inhibits renal 1alpha-hydroxylase activity and thus may be involved in the pathogenesis of SHPT. Several hypotheses were tested: that FGF-23 increases as renal function declines...