The Mechanism of Calcitriol in Cancer Prevention and Treatment

Abstract

Calcitriol (1, 25-dihydroxyvitamin D3) is the most biologically active metabolite derived from the secosteroid hormone vitamin D. Apart from its calcium homeostatic effects, epidemiological studies have shown that reduced serum calcitriol levels are associated with an increased risk of some types of cancer. Numerous recent epidemiological and experimental studies have reported that it elicits anti-proliferative, apoptotic and differentiation effects in several malignant cell types. The inhibition of calcitriol results in reduced effects of anticancer drugs. Results from a number of clinical trials revealed that sufficient dosing and exposure to calcitriol is critical for achieving antitumor effects during intermittent regimens. This review summarizes the role of calcitriol in anticancer therapy and the progress in understanding its mechanism.

Dietary Intake of Vitamin D from Dairy Products Reduces the Risk of Osteoporosis

“…Recently vitamin D supplementation was tested for its role in preventing coronavirus infections [ 54 ]. Thus, the increase in 25(OH)D concentrations with the aim of decreasing cancer risk will have other additional benefits [ 55 ]. The optimal 25(OH)D concentration is certainly above 75 nmol/L, probably close to 100–150 nmol/L; to obtain those concentrations, 1000–5000 IU/d of vitamin D3 is necessary, or a moderate amount of sun exposure [ 55 ].…”

“…Thus, the increase in 25(OH)D concentrations with the aim of decreasing cancer risk will have other additional benefits [ 55 ]. The optimal 25(OH)D concentration is certainly above 75 nmol/L, probably close to 100–150 nmol/L; to obtain those concentrations, 1000–5000 IU/d of vitamin D3 is necessary, or a moderate amount of sun exposure [ 55 ]. The only way to surely determine that the desired concentration has been obtained is to evaluate serum 25(OH)D concentration [ 56 ].…”

Vitamin D: a new anti‐infective agent?

“…The therapeutic properties of vitamin D have recently been rediscovered, and the administration of vitamin D has become increasingly common in different conditions, such as osteoporosis, rheumatic disorders, and cancer . In addition, some recent findings allude to antibiotic‐like properties of vitamin D .…”

“…The therapeutic properties of vitamin D have recently been rediscovered, and the administration of vitamin D has become increasingly common in different conditions, such as osteoporosis, 1,2 rheumatic disorders, 1,3 and cancer. 1,2 In addition, some recent findings allude to antibiotic-like properties of vitamin D. 4 Thus, this natural compound may prove to be effective against some infections, including possibly multidrug-resistant (MDR) pathogens, as an adjunct treatment modality.…”

The Potential of Vitamin D-Regulated Intracellular Signaling Pathways as Targets for Myeloid Leukemia Therapy

“…It is clear that despite the strong epidemiological evidence that optimal levels of vitamin D reduce overall mortality by at least 7% [ 212 , 213 ], while low vitamin D levels are associated with adverse outcomes in AML [ 214 ], translation of this knowledge to cancer prevention or treatment has been disappointingly slow. The early focus on the generation and testing of countless vitamin D analogs for cancer treatment has not led to encouraging results, and combinations of 1,25D or analogs with cytotoxic agents have not led to conclusive results in neoplastic diseases, including AML [ 215 , 216 , 217 ]. It appears more likely that the therapeutic regimens for AML will require the addition of small molecule inhibitors, or enhancers of signaling pathways, or entirely new strategies.…”