Search Results (99)

Vitamin D plays a key role in immune modulation, cell proliferation, and hormone regulation. Dysregulated testosterone may contribute to breast cancer progression. We investigated whether long-term vitamin D supplementation affects serum testosterone levels in breast cancer survivors. Complete data at baseline, 12, and 24 months were derived from 253 women with early-stage breast cancer participating in the DEDiCa trial and randomized to receive either a high-dose vitamin D to maintain serum 25(OH)D at 60 ng/mL (group A) or a standard dose to maintain serum levels at 30 ng/mL (group B). Serum 25(OH)D levels significantly increased in both groups (p < 0.001). No significant changes in testosterone concentrations were observed between treatment groups over the 24 month treatment period (A: 0.125 to 0.140 ng/mL; B: 0.162 to 0.193 ng/mL; p = 0.682). Baseline serum testosterone levels emerged as the most significant predictor of testosterone trajectories, possibly modulated by hormone-suppressive therapy. These results are reassuring that vitamin D supplementation did not adversely affect testosterone levels in this population of breast cancer survivors and may partially concur with a healthy lifestyle to equilibrate testosterone levels. Full article

Broiler chickens are commonly reared in closed housing systems with limited exposure to sunlight, thereby relying entirely on dietary sources of vitamin D. The hydroxylated metabolite 25-hydroxycholecalciferol [25(OH)D₃] has been proposed as a more potent form than native vitamin D₃ (cholecalciferol). This study evaluated the effects of dietary supplementation with vitamin D₃ alone or in combination with 25(OH)D₃ on growth performance, bone characteristics, and cecal microbiota in Ross 308 broilers. A total of 952 one-day-old male chicks were allocated to four treatments: a negative control (no vitamin D₃), a positive control (vitamin D₃ according to Ross 308 specifications), and a positive control supplemented with 25(OH)D₃ at 1394 or 2788 IU/kg, in a randomized design with 17 replicates per treatment and 14 birds per replicate. Over a 40-day feeding trial, diets containing vitamin D₃ (positive control) or supplemented with 25(OH)D₃ significantly improved final body weight, weight gain, average daily gain, and feed conversion ratio compared with the negative control (p < 0.01), with no significant differences among the positive control and 25(OH)D₃-supplemented groups, with a clear linear dose-dependent response. Although tibia ash and bone-breaking strength were not significantly affected, linear responses indicated a slight numerical trend toward improved skeletal mineralization with increasing 25(OH)D₃. Microbiota analysis indicated that 25(OH)D₃ affected cecal microbial ecology: low-dose inclusion showed reduced species richness and evenness, whereas high-dose inclusion restored richness to levels comparable to the positive control and enriched taxa associated with fiber fermentation and bile acid metabolism while reducing Lactobacillus dominance. In conclusion, supplementation with 25(OH)D₃ in addition to vitamin D₃ enhanced growth performance and selectively shaped the cecal microbiota of broilers, with suggestive benefits for bone mineralization. These findings highlight 25(OH)D₃ as a more potent source of vitamin D than cholecalciferol alone and support its practical use in modern broiler nutrition to improve efficiency, skeletal health, and microbial balance. Full article

Small ruminant production is a significant sector of agricultural industry in Texas, USA. Heat stress has a negative effect on productivity and animal health. Cholecalciferol, a form of vitamin D₃, may enhance the function of immune cells and help ensure healthy immune function in farm animals exposed to heat stress. Practical applications of vitamin D₃ against infectious diseases can benefit from the protective effects of a delivery system comprised of soy protein isolate and stachyose in emulsion gel. The prebiotic oligosaccharide stachyose has shown to have a great potential as a substrate for beneficial intestinal bacteria, which are thought to modulate the immune system. Cellular and humoral immunity are both impaired in dairy animals under heat stress. The delivery of vitamin D₃ embedded within the soy protein isolate-stachyose emulsion gel resulted in a marked increase in 25-hydroxyvitamin D₃ [25-(OH)-D₃] concentration in blood serum. Chicken egg albumin (OVA)-immunized goats produced low anti-OVA immunoglobulin G (IgG) responses. In contrast, OVA-immunized goats fed vitamin D₃ within the soy protein isolate-stachyose emulsion gel diet strongly stimulated antibody production. These results show that anti-OVA IgG responses can be modulated in dairy goats using vitamin D₃, particularly if this vitamin is delivered in the form of emulsion gel. The results seem to depend on the highly hydrated gel matrix of soy protein isolate-stachyose at the low pH of the stomach as monitored by oxygen-17 (¹⁷O) and proton (¹H) nuclear magnetic resonance (NMR). In addition, the prebiotic nature of stachyose may boost beneficial gut bacteria, most notably for immune health and reducing the risk of infectious diseases. Full article

Background/Objectives: Cholecalciferol and Calcifediol are commonly used for oral supplementation in patients with vitamin D deficiency. Several studies have compared these two molecules; however, the studied population has only included healthy postmenopausal women so far. This retrospective observational study aims to evaluate which molecule is more effective and faster in achieving serum 25(oh)D levels within the normal range in post-stroke patients during the subacute phase. Secondary aims include assessing potential differences in functional outcomes and investigating the possible correlation between the degree of hypovitaminosis D and stroke severity. Methods: We observed 85 in-patients who received either Cholecalciferol or Calcifediol during intensive rehabilitation. All subjects underwent functional evaluations, blood tests, and a bone densitometry (DEXA) scan. Results: Four months after starting supplementation, subjects receiving calcifediol achieved significantly higher 25(oh)D levels (p < 0.001) compared to those receiving cholecalciferol. No significant between-group differences were observed in secondary outcomes. Another key finding is that no statistically significant correlation was found between serum of 25(oh)D levels and stroke severity. Conclusions: These results highlight the importance of further investigating bone metabolism in post-stroke patients, though findings should be confirmed in larger studies. Full article

Background: Patients with end-stage chronic diseases, especially those undergoing hemodialysis (HD), often experience mineral bone disease (MBD), leading to hypocalcemia, hyperphosphatemia, and elevated parathyroid hormone (PTH). Vitamin D deficiency and metabolism disorders are also common, resulting from impaired conversion of 25(OH)D3 to its active form, 1,25(OH)2D3, and reduced inactivation to 24,25(OH)2D3. This study aimed to assess the levels of 25(OH)D2, 25(OH)D3, 24,25(OH)2D3, 3-epi-25(OH)D3, and the vitamin D metabolism ratio (VMR) in patients with maintenance HD. Methods: A cross-sectional study was conducted on 66 HD patients (22–90 years, average 61.3 ± 16.4), with a control group of 206 adults without chronic kidney disease (CKD), both without cholecalciferol supplementation. Results: the HD patients had significantly lower 25(OH)D3 levels (15 ng/mL vs. 22 ng/mL) and higher deficiency rates (69% vs. 39%) compared to the controls. However, both groups showed similarly low levels of optimal vitamin D3. The HD patients had lower 24,25(OH)D3 levels (0.1 vs. 2.1 ng/mL) and a lower VMR (0.9% vs. 9%). 3-epi-25(OH)D3 levels and its ratio to 25(OH)D3 were significantly lower in the HD group. Alphacalcidol supplementation raised 1,25(OH)2D3 levels (30.4 vs. 16.2 pg/mL) without affecting other vitamin D metabolites. The HD patients had higher levels of 25(OH)D2 compared to the controls (0.61 vs. 0.31 ng/mL). Conclusions: Vitamin D3 reserves are lower, and both functional deficiency and impaired catabolism of vitamin D3 are present in HD patients compared to the general population. The VMR index is the most sensitive parameter for vitamin D3 deficiency assessment, highlighting the importance of measuring 24,25(OH)D3. Alphacalcidol supplementation increases 1,25(OH)2D3 levels without affecting other vitamin D metabolites. 25(OH)D2 is the only metabolite that was higher in HD patients than the controls. Full article

Clinical trials consistently demonstrate an inverse correlation between serum 25-hydroxyvitamin D [25(OH)D; calcifediol] levels and the risk of symptomatic SARS-CoV-2 disease, complications, and mortality. This systematic review (SR), guided by Bradford Hill’s causality criteria, analyzed 294 peer-reviewed manuscripts published between December 2019 and November 2024, focusing on plausibility, consistency, and biological gradient. Evidence confirms that cholecalciferol (D₃) and calcifediol significantly reduce symptomatic disease, complications, hospitalizations, and mortality, with optimal effects above 50 ng/mL. While vitamin D requires 3–4 days to act, calcifediol shows effects within 24 h. Among 329 trials, only 11 (3%) showed no benefit due to flawed designs. At USD 2/patient, D₃ supplementation is far cheaper than hospitalization costs and more effective than standard interventions. This SR establishes a strong inverse relationship between 25(OH)D levels and SARS-CoV-2 vulnerability, meeting Hill’s criteria. Vitamin D₃ and calcifediol reduce infections, complications, hospitalizations, and deaths by ~50%, outperforming all patented, FDA-approved COVID-19 therapies. With over 300 trials confirming these findings, waiting for further studies is unnecessary before incorporating them into clinical protocols. Health agencies and scientific societies must recognize the significance of these results and incorporate D₃ and calcifediol for prophylaxis and early treatment protocols of SARS-CoV-2 and similar viral infections. Promoting safe sun exposure and adequate vitamin D₃ supplementation within communities to maintain 25(OH)D levels above 40 ng/mL (therapeutic range: 40–80 ng/mL) strengthens immune systems, reduces hospitalizations and deaths, and significantly lowers healthcare costs. When serum 25(OH)D levels exceed 70 ng/mL, taking vitamin K₂ (100 µg/day or 800 µg/week) alongside vitamin D helps direct any excess calcium to bones. The recommended vitamin D dosage (approximately 70 IU/kg of body weight for a non-obese adult) to maintain 25(OH)D levels between 50–100 ng/mL is safe and cost-effective for disease prevention, ensuring optimal health outcomes. Full article

Vitamin D toxicosis poses a health threat to dogs, with cases often stemming from cholecalciferol rodenticide ingestion. This case report investigates two clinical cases of canine cholecalciferol toxicosis, shedding light on the persistent elevation of 25-hydroxyvitamin D (25(OH)D) and the adaptive response of 24,25-dihydroxyvitamin D (24,25(OH)₂D). Serum samples from affected dogs were analyzed over several months, revealing sustained increases in 25(OH)D concentrations. Notably, concurrent measurements of 24,25(OH)₂D unveiled a marked elevation, suggesting a compensatory mechanism to mitigate calcitriol excess and hypercalcemia. These findings highlight the potential role of upregulating 24-hydroxylase activity as a therapeutic target for managing cholecalciferol toxicosis. These cases underscore the importance of understanding vitamin D metabolism in canine toxicology and prompt further exploration into novel treatment strategies and other research areas. Full article

(1) Background and Objectives: Vitamin D is implicated in the pathogenesis of Chronic Kidney Disease—Mineral and Bone Disorder (CKD-MBD) in hemodialysis (HD) patients, including the development of secondary hyperparathyroidism (SHP). While cholecalciferol supplementation is recommended for vitamin D deficiency correction, its impact on CKD-MBD remains inconsistent. The aim of this observational prospective study was to assess the effect of cholecalciferol in achieving high–normal serum 25-hydroxycholecalciferol (25(OH)D > 75 ng/mL) levels and its impact on CKD-MBD biochemical markers, including 1,25-dihydroxycholecalciferol (1,25(OH)₂D) and parathormone (PTH) in HD patients. The study also evaluated the maintenance dosage required to sustain 25(OH)D levels within the 50–75 ng/mL range. (2) Materials and Methods: A total of 22 HD patients with baseline 25(OH)D levels 30–50 ng/mL received cholecalciferol (70,000 IU/week) to achieve the target serum 25(OH)D > 75 ng/mL. Baseline data on calcium, phosphate, 1–84 PTH, 25(OH)D, and 1,25(OH)₂D serum levels were compared with the data when 25(OH)D > 75 ng/mL was targeted or when the highest 25(OH)D levels were noted. (3) Results: Cholecalciferol significantly improved vitamin D status in HD patients, with 73% reaching the target 25(OH)D level >75 ng/mL in a median time of 7.5 weeks, with a median total dose of 525,000 IU. This was associated with a significant rise in 1,25(OH)₂D, decrease in 1–84 PTH, and no significant effect on calcium and phosphate levels. The median maintenance dose of cholecalciferol was established at 30,000 IU/week. (4) Conclusions: The findings support the use of cholecalciferol targeting high normal 25(OH)D levels to improve biochemical markers of CKD-MBD in HD patients. Full article

Background: There are few and controversial results on 24,25(OH)₂D and FGF23 acute changes following supplementation with cholecalciferol. Methods: Twenty-seven subjects with 25(OH)D < 30 ng/mL were randomized into three groups to receive a single oral dose of 25,000 I.U. or 600,000 I.U. of cholecalciferol or placebo, respectively. We measured 25(OH)D, 1,25(OH)₂D, 24,25(OH)₂D, and FGF23 levels at baseline and after 72 h. The 1,25(OH)₂D/25(OH)D, 1,25(OH)₂D/24,25(OH)₂D, and 24,25(OH)₂D/25(OH)D ratios were also calculated. Results: There was an increase in 25(OH)D and 1,25 (OH)₂D following both doses of cholecalciferol. In the group administered 600,000 I.U., there was a significant increase in the delta changes in 25(OH)D and 1,25(OH)₂D compared to the placebo and in the delta 24,25(OH)D₂ compared to the placebo and 25,000 I.U. groups (all p < 0.05). A decrease in both the 1,25(OH)₂D/25(OH)D and 1,25(OH)₂D/24,25(OH)₂D ratio (all p < 0.05) was observed in the 600,000 I.U. group. FGF23 values significantly increased only in the group administered 600,000 I.U. Conclusions: 25(OH)D and 1,25(OH)D levels significantly increased following 600,000 IU cholecalciferol administration compared to 25,000 I.U. and placebo. Following the massive administration of cholecalciferol, the CYP24A1 enzyme is actively involved in catabolism, thus, avoiding toxic effects. Full article

This study aimed to detect seasonal and species differences in serum 25-hydroxy vitamin D (25(OH)D) concentrations during summer and winter months in captive pachyderms in Europe. Both elephant species had low 25(OH)D while African elephants did not show a seasonal variation. Asian elephants had significantly higher 25(OH)D compared to their African counterparts but also did not show a seasonal difference. Both rhinoceros species investigated had higher 25(OH)D compared to both elephant species; the Indian rhinoceros had high circulating levels year-round, while the black rhinoceroses showed significantly lower 25(OH)D in winter. Malayan tapirs have very low 25(OH)D, comparable to horses. The higher 25(OH)D of elephants and rhinoceroses could indicate that elephants and rhinoceroses are capable of producing vitamin D. This might indicate that the Indian rhinoceroses are capable of producing enough endogenous vitamin D year-round at latitudes around 52° N, while both elephant species and the black rhinoceros are not. This study also showed that it is likely that both elephant species and rhinoceros species are capable of absorbing cholecalciferol from the digestive tract, according to the existing literature, while tapirs may not. 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

Background: Antiseizure medications (ASMs) are crucial for managing epilepsy in children. However, a well-documented side effect of ASMs is their impact on bone health, often due to interference with vitamin D metabolism. This can lead to vitamin D deficiency in children with epilepsy. This study aimed to determine if a daily dose of 400 IU or 1000 IU would maintain adequate vitamin D levels in children with epilepsy. Methods: A phase IV randomized controlled trial enrolled children aged 2–16 years with epilepsy and receiving antiseizure medications. Children were divided into two groups: the monotherapy group, which was defined as children on one antiseizure medication (ASM), and the polytherapy group, which was defined as children receiving two or more ASMs. Eligible children with levels above 75 nmol/L were randomized to receive a maintenance dose of either 400 IU/day or 1000 IU/day of cholecalciferol. Baseline and 6-month assessments included demographic data, anthropometric measurements, seizure type, medications, seizure control, and 25(OH)D level. Results: Out of 163 children, 90 were on monotherapy and 25 on polytherapy. After 6 months of vitamin D maintenance, the proportion of children with 25(OH)D concentration below 75 nmol/L was 75.0% in the 400 IU group and 54.8% in the 1000 IU group. In the monotherapy group, baseline seizure-free children increased from 69% to 83.6% after treating vitamin D deficiency. Conclusion: Daily vitamin D supplementation with 1000 IU may be beneficial for children with epilepsy, particularly those receiving monotherapy, to maintain sufficiency and potentially improve seizure control. Full article

Despite numerous scientific reports on the negative impact of vitamin D3 deficiency on many respiratory diseases, little is known about the influence of this phenomenon on the development and progression of hypersensitivity pneumonitis (HP). The presented study is an attempt to shed light on this occurrence. The research was performed on mouse strain C57BL/6J exposed to the antigen of Pantoea agglomerans (etiological factor of HP). To induce vitamin D3 deficiency, mice received a diet with a 10 times lower amount of cholecalciferol than the main control group. VD3-deficient mice inhaled 25(OH)-VD3 or 1,25(OH)2-VD3 used separately or with SE-PA. At the beginning of the experiment and after 14 and 28 days of inhalation, respiratory function was examined using whole-body plethysmography. Moreover, at indicated time points, mice were sacrificed and samples collected for histological examination, flow cytometry, and ELISA. The performed study revealed that inhalations with 25(OH)-VD3 and 1,25(OH)2-VD3 effectively eliminated most of the negative changes in the respiratory system caused by vitamin D3 deficiency by restoring the physiological concentration of 1,25(OH)₂-VD3 in the body. VD3-deficient mice which inhaled P. agglomerans antigen and vitamin D3 metabolites also demonstrated the ability of the tested compounds to eliminate, or at least weaken, the negative effects of the HP causative factor and desired effect, including improvement of respiratory functions and attenuation of inflammation and signs of fibrosis. The obtained results suggested that the beneficial influence of inhaled vitamin D3 metabolites on HP development was associated with the restoration of the physiological concentration of 1,25(OH)2-VD3 in the pulmonary compartments in VD3-deficient mice. Full article

High dose bolus cholecalciferol supplementation has been associated with falls and fracture, and this does not appear to be due to hypercalcaemia. The primary aim of this study was to determine the change in free vitamin D and metabolites after high dose bolus supplementation. This was a single centre, double-blinded, randomised, controlled trial of three different oral bolus doses of vitamin D₃ (50,000 IU, 150,000 IU, and 500,000 IU) in otherwise healthy, vitamin D deficient (total 25-hydroxylated vitamin 25(OH)D < 30 nmol/L) postmenopausal women. Thirty-three women were randomized to one of the three treatment groups. Twenty-seven vitamin D sufficient (25(OH)D > 50 nmol/L) postmenopausal women were recruited as a concurrent control group. Participants attended five study visits over three months. We measured total 25(OH)D₃ and free 25(OH)D, total and free 1,25(OH)₂D, parathyroid hormone, fibroblast-growth factor-23, serum calcium, ionised calcium, urinary calcium excretion, and bone turnover markers (procollagen I N-propeptide (PINP), serum C-telopeptides of type I collagen (CTX-I) and Osteocalcin (OC)). We assessed muscle strength and function with grip strength and a short physical performance battery. Postural blood pressure and aldosterone:renin ratio (ARR) was also measured. Total 25(OH)D₃ and free 25(OH)D increased in response to dose, and there were proportionate increases in total and free metabolites. Treatment did not affect serum calcium, postural blood pressure, ARR, or physical function. Bone turnover markers increased transiently one week after administration of 500,000 IU. High dose bolus cholecalciferol supplementation does not cause disproportionate increases in free vitamin D or metabolites. We did not identify any effect on blood pressure regulation or physical function that would explain increased falls after high dose treatment. A transient increase in bone turnover markers one week after a 500,000 IU bolus suggests that very high doses can have acute effects on bone metabolism, but the clinical significance of this transient increase is uncertain. Full article

Recent studies have demonstrated the relationship between vitamin D deficiency, infection severity and mortality from COVID-19. This study aimed to analyze the vitamin D metabolites and cytokine expression levels of COVID-19 patients who were hospitalized with bolus cholecalciferol supplementation. Materials and methods: This study represents the next stage of the open-label randomized pilot conducted by the Almazov National Medical Research Centre. A total of 44 hospitalized patients, comparable in demographic, clinical, laboratory and instrumental baseline characteristics, with moderate/severe COVID-19 were included. All patients had similar doses of concomitant corticosteroid therapy. Twenty-two patients received 50,000 IU cholecalciferol on the first and eighth days of hospitalization. The serum 25(OH)D, 1,25(OH)2D and 28 plasma cytokines were estimated for each group initially and on the ninth day of hospitalization. Results: Initially, there were no differences in the 1,25(OH)2D and cytokine levels in patients with vitamin D deficiency and normal 25(OH)D. Bolus cholecalciferol therapy at a total dose of 100,000 IU led to an increase in 25(OH)D levels in hospitalized patients with COVID-19, while the levels of the active metabolite (1,25(OH)2D) did not show significant differences between the groups or in its increased level over time, regardless of cholecalciferol supplementation. Furthermore, cholecalciferol supplementation at a total dose of 100,000 IU did not affect the majority of the cytokines estimated on the ninth day of hospitalization, except for the pro-inflammatory marker IL-1b, the concentration of which was lower in the group of patients without vitamin D supplementation. Conclusions: The 25(OH)D level was positively associated with an anti-inflammatory immune response, but cholecalciferol supplementation at a total dose of 100,000 IU did not affect the active-form vitamin D or cytokine expression levels. This fact may be explained by the impact of corticosteroid therapy, and it requires further investigation in a post-COVID-19 context. Full article