Search Results (76)

We synthesized two vitamin D₃ analogues, 3 and 4, which have a shortened or elongated fluoro-side-chain based on 24,24-difluoro-25-hydroxyvitamin D₃ (5) using an efficient convergent approach and studied their preliminary biological activity. Both analogues exhibited greater resistance to CYP24A1-mediated metabolism than the natural 25-hydroxyvitamin D₃ (6), although their stability was lower than that of 5. Analogue 3 showed an approximately 100-fold lower human vitamin D receptor (hVDR)-binding affinity compared with 5 and 6. Despite this marked reduction in VDR-binding affinity, it demonstrated an approximately 1.5-fold increase in VDR-ligand binding domain (LBD) transcriptional activation of the natural ligand 6. In contrast, analogue 4 displayed moderate VDR-binding affinity and VDR-LBD transactivation compared with 5 and 6. We found that compound 3 is a unique vitamin D analogue with a fluorinated and shortened side-chain, exhibiting low binding affinity for hVDR but potent transcriptional activity through VDR-LBD with its long half-life; thus, 3 may serve as a basic structural skeleton for advancing medicinal chemistry and drug discovery. Full article

Vitamin D exists in various forms and plays a central role in the absorption and regulation of calcium and phosphate. In chronic kidney disease, vitamin D concentrations become progressively reduced with the deterioration of kidney function, which becomes even more pronounced in end-stage kidney disease. Herein, we aim to summarize existing data regarding the pathogenetic role of vitamin D in dialysis and the potential effect of supplementation of various forms of vitamin D on hard and surrogate clinical endpoints. We performed a narrative review, gathering existing observational and clinical studies from 2001 to 2025 in English in the Medline/PubMed database, along with current guidelines and consensus statements regarding the use of vitamin D and D analogues in end-stage kidney disease patients. Vitamin D should be monitored and corrected, but supraphysiologic doses should be avoided, as well as very high levels of vitamin D to avoid toxicity. In dialysis, native D is used only to correct vitamin D deficiency; the real target here is secondary hyperparathyroidism, where vitamin D analogues and calcimimetics should be administered. Full article

Tertiary hyperparathyroidism (THPT) arises in patients with chronic kidney disease (CKD) as a consequence of prolonged secondary hyperparathyroidism and is marked by autonomous parathyroid hormone (PTH) secretion. In some cases, parathyroid hyperplasia persists even after successful renal transplantation, resulting in sustained PTH elevation and hypercalcaemia. These alterations contribute to bone loss, vascular calcification, and increased cardiovascular risk. Management includes medical therapy with calcimimetics or vitamin D analogues and surgical intervention via parathyroidectomy. However, optimal timing and treatment strategy remain uncertain. This review examines the pathophysiology, clinical manifestations, and current management paradigms of THPT, with an emphasis on areas that require further research and consensus. Full article

Calcipotriol, a synthetic vitamin D₃ analogue widely used in psoriasis treatment, requires a detailed stability assessment due to its topical application and potential exposure to UV radiation. As a drug applied directly to the skin, calcipotriol is particularly susceptible to photodegradation, which may affect its therapeutic efficacy and safety profile. The present study focuses on the analysis of calcipotriol photostability. An advanced UHPLC/MS^E method was employed for the precise determination of calcipotriol and its degradation products. Particular attention was given to the effects of commonly used organic UV filters—approved for use in cosmetic products in both Europe and the USA (benzophenone-3, dioxybenzone, meradimate, sulisobenzone, homosalate, and avobenzone)—on the stability of calcipotriol. Unexpected degradation of calcipotriol was observed in the presence of sulisobenzone. Importantly, this effect was consistently detected in methanolic solution and in the pharmaceutical formulation containing calcipotriol and betamethasone, which is particularly significant from a practical perspective. This finding underscores the necessity of evaluating photostability under real-life conditions, as cosmetic ingredients, when co-applied with topical drugs on the skin, may substantially influence the stability profile of the pharmaceutical active ingredient. The research resulted in the first-time characterization of four degradation products of calcipotriol. The degradation process was found to primarily affect the E-4-cyclopropyl-4-hydroxy-1-methylbut-2-en-1-yl moiety, causing its isomerization to the Z isomer and the formation of diastereomers with either the R or S configuration. Computational analyses using the OSIRIS Property Explorer indicated that none of the five degradation products exhibit a toxicity effect, whereas molecular docking studies suggested possible binding of two of the five degradation products of calcipotriol with the VDR. Full article

Psoriasis is a chronic inflammatory autoimmune disease that causes significant deterioration of the quality of life, and due to its multifactorial causes, it is often difficult to manage. Apart from genetic and environmental components, an important part of its pathophysiology comprises an oxidative stress induction that the standard antioxidative mechanisms of the human body cannot compensate for. Moreover, in many psoriatic patients, there is a documented imbalance between antioxidant and pro-oxidative factors. Usually, psoriasis is evaluated using the Psoriasis Area and Severity Index (PASI) score. It has been demonstrated that dietary choices can lead to significant modification of PASI scores. Hypocaloric diets that are rich in antioxidants are highly effective in this regard, especially when focusing on vegetables and restricting consumption of animal-derived protein. Specific dietary regimens, namely the Mediterranean diet and potentially the ketogenic diet, are very beneficial, in the former case owing in large part to the omega-three fatty acids it provides and its ability to alter gut microbiome, a factor which seems to play a notable role in the pathogenesis of the disease. Another option is the topical application of vitamin D and its analogues, combined with corticosteroids, which can ameliorate the manifestations of psoriasis at the level of the skin. Finally, oral vitamin D supplementation has a positive impact on psoriatic arthritis and can mitigate the risk of associated comorbidities. Full article

The active form of vitamin D₃, 1α,25-dihydroxyvitamin D₃ (1,25D₃), regulates a number of physiological and pathological processes, including cell proliferation and differentiation. Thousands of analogues of 1,25D₃ have been developed with the aim of selective effects for medical use. Here we describe the synthesis of two new unconventional vitamin D analogues bearing A-ring modifications with ortho-carborane (dicarba-o-closo-1,2-dodecaborane) units. The ligands function as agonists for VDR with similar antiproliferative activities as 1,25D₃. Whereas mice treated with the analogues 4 and 5 exhibited similar hypercalcemic activities as 1,25D₃, only compound 4 and 1,25D₃ induced the strong activation of CYP24A1 mRNA expression but not compound 5. Full article

Background/Objectives: To evaluate the neuromodulative effects of oral intake of a fixed combination of citicoline 500 mg plus homotaurine 50 mg plus vitamin B3 54 mg plus pyrroloquinoline quinone (CIT/HOMO/B3/PPQ) or of citicoline 800 mg alone (CIT800) on retinal ganglion cell (RGC) function in glaucoma patients by pattern electroretinogram (PERG) and to investigate the effects on quality of life and visual function. Methods: Consecutive patients with primary open-angle glaucoma with controlled IOP (<18 mmHg) receiving prostaglandin analogues as monotherapy; with two reliable visual fields (Humphrey 24-2 SITA Standard) per year in the last 2 years; and an early to moderate visual field defect (MD < −12 dB) were randomized to: arm A. topical therapy + CIT/HOMO/B3/PPQ for 4 months, followed by 4 months of topical therapy + CIT800; and arm B. topical therapy + CIT800 for 4 months, then topical therapy + CIT/HOMO/B3/PPG for 4 months. Patients were examined at month 0, 4, and 8. Complete ocular examination, visual field test, PERG, and quality of life assessment (NEI-VFQ25) were performed at each visit. Results: Forty patients were selected and completed the study, and none developed or reported an adverse event. The overall mean age was 64.2 (±7.7) years, 27 were male. At the end of the intake period of both products, patients exhibited higher P50 and N95-wave amplitudes and shorter latencies compared to baseline. The crossover analysis found that PERG parameters were better when patients received the CIT/HOMO/B3/PQQ combination with a statistically significant shorter peak time of 1.24 ms (95% CI, 0.37 to 2.10; p = 0.006) in the central P50 wave, 1.32 ms (95% CI, 0.44 to 2.22; p = 0.004) in the inferior P50 wave, and 1.70 ms (95% CI, 0.09 to 3.31; p = 0.038) in the inferior N95 wave; and a statistically significant increase of 0.35 µV (95% CI, 0.10 to 0.60; p = 0.006) in the superior N95 amplitude. The crossover analysis did not reveal any significant differences between the intake of CIT800 and CIT/HOMO/B3/PQQ in terms of visual acuity or IOP. During the intake of CIT/HOMO/B3/PQQ, a significant improvement was observed in the total mean score (p = 0.004), in the general health scale (GH, p = 0.01), in the color vision scale (p = 0.006), and in the peripheral vision scale (p = 0.001). Conclusions: The present study has shown that the addition of CIT/HOMO/B3/PQQ in early glaucoma improves PERG parameters and quality of life, likely by slowing down RGC aging and enhancing mitochondrial function more significantly than citicoline 800 mg alone. Full article

Vitamin D, a hormone synthesized in the skin through ultraviolet B radiation (UVB), plays a crucial role not only in calcium and phosphate homeostasis but also in regulating skin homeostasis and modulating immune responses. In keratinocytes, vitamin D is converted to its active form, 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D), which interacts with the vitamin D receptor (VDR) to regulate gene expression involved in proliferation, differentiation, and antimicrobial defense. Dysregulation of this pathway has been implicated in inflammatory skin diseases such as psoriasis, atopic dermatitis, acne vulgaris, and hidradenitis suppurativa. These conditions are associated with altered epidermal differentiation, immune imbalance, and microbial interactions, where vitamin D plays a modulatory role by suppressing proinflammatory cytokines, enhancing antimicrobial peptide synthesis, and restoring skin barrier integrity. Topical vitamin D analogues have shown therapeutic benefits in psoriasis, while emerging evidence supports the adjunctive role of vitamin D supplementation in acne, hidradenitis suppurativa, and atopic dermatitis. Despite promising associations between low serum vitamin D levels and disease severity, a causal relationship remains uncertain. This review integrates molecular mechanisms with clinical findings, emphasizing the role of vitamin D in cutaneous physiology and pathology, and highlights the need for further research into targeted supplementation strategies in dermatological disorders. Full article

Vitamin D and its metabolites are essential in various physiological processes, including muscle strength, metabolism, antifibrotic activity, and immune regulation. Researchers are focusing on developing vitamin D derivatives with optimized receptor selectivity and reduced systemic toxicity, enhancing their therapeutic efficacy against cancer, autoimmune disorders, and inflammatory diseases. Several analogues, such as alfacalcidol, paricalcitol, and falecalcitriol, are used for managing CKD-related bone disorders, while eldecalcitol is effective for osteoporosis, and calcipotriol against psoriasis. Recent studies have explored their impact on metabolic pathways, parathyroid hormone secretion, asthma, and liver fibrosis, revealing their broad clinical potential. Despite enormous efforts in the past decades, translations of vitamin D-drugs are disproportionately limited, mainly due to toxicity due to calcemic effects and undesirable metabolic profile. This review discusses structural modifications in vitamin D3, their influence on VDR binding, transcriptional activity, and calcium homeostasis, along with their role in targeting pathways like EGFR, KRAS, and Hedgehog in cancers. Advanced analytical techniques such as LC/ESI-MS/MS facilitate precise detection of vitamin D metabolites, further improving pharmacokinetic profiling. Future research may enable the clinical approval of novel vitamin D-based therapeutics with minimal disruption to calcium–phosphorus balance. Full article

Abstract: Objectives: Bone mineral density (BMD) variation under vitamin D supplementation, determined using dual-energy X-ray absorptiometry (DXA), is the gold standard and the main tool used in most studies in this domain. However, the scientific literature is lacking with regard to the usefulness of REMS in BMD follow-up, especially the importance of the fragility score (FS). The main objective of this study was to determine whether FS follow-up is relevant in a group of patients with axial spondyloarthritis and whether REMS could have clinical applicability. Methods: Patients with a certain diagnosis of axial spondyloarthritis (AxSpA) were recruited from two medical healthcare centers and were scanned using Radiofrequency Echographic Multi-Spectrometry in order to obtain their fragility score (FS), an objective measurement of bone quality. The main group was randomized into a vitamin D supplementation branch and a non-supplementation branch and followed up every 6 months for 18 months in total. Comparisons between the branches were made using MiniTab v.20 statistical software. Results: Lower FS values were obtained in patients who initially had high scores, suggesting a positive impact of vitamin D on bone quality (p = 0.008). Muscle strength was evaluated through a visual analogue scale (VAS), with improvements being seen in the supplementation branch (p < 0.005). Furthermore, although some patients had experienced falls in previous years, during the study period, no new events were recorded in either group. Conclusions: The FS is a reliable tool for evaluating bone architecture and is useful in everyday practice for the management of patients taking vitamin D supplements. Full article

Lymphomas represent a heterogeneous group of blood tumors, generally divided into non-Hodgkin lymphoma (NHL) (90% of all lymphomas) and Hodgkin lymphoma (HL). High-grade NHL can rapidly progress so that new strategies and potentially therapeutical options are needed. Recently, it was shown that Vitamin D (VitD) inhibits the growth of cancer cells, controls their invasion and metastasis, and strengthens the antitumor activity of various types of chemotherapeutic anticancer agents. Therefore, we reviewed the recent literature about the influence of VitD and its analogues (VDAs) on the treatment and the prognosis of B-cell lymphomas. As to the in vitro studies in different cell lines, VitD3 and VDAs enhanced the anti-proliferative efficacy of various chemotherapeutics and increased the expression of VitD receptor. In in vivo studies, blood levels of VitD were considered: higher values of plasma bioavailable VitD were correlated with better progression-free survival (PFS) and overall survival (OS), while an unfavorable PFS and OS were observed in VitD deficient groups. No clinical trial was made on the analogs, thus confirming the absence of in vivo positive role of these synthetic drugs. In conclusion, higher levels of circulating VitD are related to improved OS, reduced cancer-specific mortality, and better disease-free survival. VitD and analogs showed also positive effects in in vitro studies, while only VitD was able to improve clinical parameters. Furthermore, a complex approach with plant-based diet, adequate levels for motor exercise, and/or eventual VitD supplementation could be a valuable strategy to challenge lymphomas. Full article

The Hedgehog (Hh) signaling pathway plays a crucial role in the initiation and progression of tumors, and Hh inhibitors have been used as potential chemotherapeutic agents for the treatment of basal cell carcinomas (BCCs). Vitamin D₃ (VD₃) and its derivatives have been identified as potent Hh inhibitors. However, the selectivity of VD₃ derivatives to vitamin D receptor (VDR) and the Hh signaling pathway still needs optimization. In this study, a series of aromatic A-ring mimics VD₃ analogues that contain a C-23 oxygen atom or incorporate C-25 hydroxyl on side chains were designed and synthesized. These compounds were tested in various cell lines for anti-Hh activity, with analogues 3j and 4i identified as potent inhibitors. Mechanism studies showed their anti-Hh effects are mainly due to targeting Smoothened (Smo) without binding to the cyclopamine site. Structure-activity relationship (SAR) studies revealed that VD₃-based inhibitors enhance anti-Hh activity by adding a hydroxyl group at C25 while reducing VDR activity by incorporating an oxygen atom into the side chain. Full article

Objectives: To investigate the correlation between baseline serum concentrations of 25-hydroxyvitamin D (25-OHD) and quality of life (QoL), as well as pain perception in patients with chronic pain with long-term prescription opioid usage before opioid detoxification. Methods: We prospectively studied 45 patients with chronic pain with long-term prescription opioid usage who were selected for elective detoxification. Baseline serum 25-OHD levels were measured prior to detoxification, classifying patients as either vitamin D deficient (<75 nmol/L) or sufficient (≥75 nmol/L). QoL was assessed using the SF-36v2^TM questionnaire, while pain levels were assessed using Visual Analogue Scale (VAS) scores before treatment. Results: Mean pain scores before detoxification of the patients with sufficient baseline 25-OHD levels vs. those with deficient levels were, respectively, 6.06 ± 2.32 vs. 6.86 ± 2.10 (normalized scores 1.22 ± 0.571 vs. 0.950 ± 0.632; p = 0.164). The analysis of SF-36v2™ questionnaire scores revealed minimal variation between groups (35.00 ± 14.198 vs. 34.97 ± 13.52), indicating no significant association between Vitamin D levels and QoL (p = 0.913). Conclusions: The analysis of baseline 25-OHD levels in relation to QoL assessments and pain scores did not reveal a statistically significant association, indicating that variations in baseline vitamin D levels may not substantially impact QoL or pain perception. Further studies may help determine how to assess and optimize vitamin D levels in patients with chronic pain on long-term prescription opioids. Full article

The active metabolite of vitamin D3, calcitriol (1,25D), is widely recognised for its direct anti-proliferative and pro-differentiation effects. However, 1,25D is calcaemic, which restricts its clinical use for cancer treatment. Non-calcaemic agonists of the vitamin D receptor (VDR) could be better candidates for cancer treatment. In this study, we examined the influence of the hydroxylated lithocholic acid derivative CAR-R on osteosarcoma (OS) cell (MG63) growth and differentiation. Treatment of MG63 cells with CAR-R inhibited growth under conventional and hypoxic conditions. Co-treating cells with CAR-R and a lysophosphatidic acid (LPA) analogue resulted in their differentiation, as supported by synergistic increases in alkaline phosphatase (ALP) activity. Under hypoxic conditions, however, this differentiation response was attenuated. The importance of observed increases in hypoxia inducible factors (HIFs) were investigated through targeted disruption using pharmacological and genetic approaches. Disruption elicited a reduction in ALP activity, suggesting an important role for HIFs in OS differentiation. Finally, we examined the expression of the VDR protein. Hypoxic MG63s expressed less VDR, with the levels increasing with CAR-R exposure. Whilst these findings are encouraging, future studies aimed at bolstering the pro-differentiating effect of CAR-R under hypoxic conditions are warranted if this agent is to gain traction in the treatment of OS. Full article

Epidemiological and observational studies suggest that vitamin D has potential for the chemoprevention of ovarian cancer. The anticancer effect of vitamin D in the fallopian tube epithelium (FTE), which is now thought to harbor the precursor cells for high grade ovarian cancer, is not known. The purpose of this study was to investigate whether vitamin D can inhibit carcinogenesis in the mogp-TAg fallopian tube (FT) ovarian cancer mouse model and examine underlying mechanisms. To test this hypothesis, 3 groups of 40 5-week-old female mogp-TAg mice were divided equally into two cohorts of 20 mice, treated with either vehicle (vitamin D solvent) or the active 1,25(OH)2D3 analogue EB1089, delivered via mini-pump or IP injection or cholecalciferol delivered in the feed. The FTs were characterized histologically and pathologically after 3 and 7 weeks of treatment. The effect of vitamin D on cultured human FTE cells was also examined. After 3 weeks, vitamin D, delivered as either cholecalciferol or EB1089 significantly inhibited FT carcinogenesis. After 7 weeks, cholecalciferol significantly reduced p53 signatures, serous tubal epithelial carcinoma, FT cancer, and plasma CA125 while increasing apoptosis in the FTE. EB1089 had no significant effect on FT carcinogenesis at 7 weeks. Cholecalciferol significantly reduced proliferation and increased apoptosis in vitro in p53-altered FTE cells. In conclusion, vitamin D inhibited FT carcinogenesis by clearing cells with p53 alterations. These data suggest that vitamin D has merit for the chemoprevention of fallopian tube/ovarian cancer. The optimal chemopreventive effect may be dependent on the route of vitamin D administration Full article