Is calcifediol better than cholecalciferol for vitamin D supplementation?

Treatment response variations to a single large bolus of enteral cholecalciferol in vitamin D deficient critically Ill children: Metabolomic insights for precision nutrition

Vitamin D deficiency (VDD) is prevalent globally and in pediatric intensive care units, where it represents a modifiable risk factor that may impact patient recovery during hospitalization. Herein, we performed a retrospective analysis of serum samples from a phase-II randomized placebo-controlled trial involving a single large bolus of 10,000 IU/kg vitamin D3 ingested by critically ill children with VDD (25-OH-D < 50 nmol/L). Targeted and untargeted methods were used to comprehensively measure 6 vitamin D metabolites, 239 lipids, 68 polar metabolites, and 4 electrolytes using a multi-step data workflow for compound authentication. Complementary statistical methods classified circulating metabolites/lipids associated with vitamin D repletion following high-dose vitamin D3 intake (n = 20) versus placebo (n = 11) comprising an optional standard of care maintenance dose (< 1000 IU/day). There was a striking increase in median serum concentrations of 25-OH-D3 (4.7-fold), 3-epi-25-OH-D3 (24-fold) and their C3-epimer ratio (6.7-fold) in treated patients on day 3, whereas serum vitamin D3 peaked on day 1 (128-fold) unlike placebo. Treatment response differences were attributed to D3 bioavailability and C3-epimerase activity without evidence of hypercalcemia. For the first time, we report the detection of circulating 3-epi-D3 that was strongly correlated with vitamin D3 uptake (r = 0.898). Metabolomic studies revealed that vitamin D sufficiency (serum 25-OH-D >75 nmol/L) coincided with lower circulating levels of 3-methylhistidine, cystine, S-methylcysteine, uric acid, and two lysophosphatidylcholines 7 days after treatment. Rapid correction of VDD was associated with indicators of lower oxidative stress, inflammation, and muscle protein turn-over that may contribute clinical benefits in high-risk critically ill children.

Contribution of different vitamin D forms and fortified foods to vitamin D intake in Europe: a narrative review

In the current narrative review, the bioavailability of the main vitamin D forms is evaluated. The mean intakes and main contributing forms of vitamin D in the European diet are estimated, as well as the major contributing dietary sources. The literature is reviewed for studies reporting on the proportion of users and non-users of fortified food with vitamin D intakes below reference intakes. In addition, the availability of vitamin D-fortified prepackaged retail products and fortification levels in the European market is assessed. Previously, vitamins D2 and D3 forms were considered the primary forms in the diet. Recent analytical methods suggest that dietary 25(OH)D3, when adjusted for higher bioequivalence, significantly contributes to total vitamin D intakes. When also considering 25(OH)D3 from foods, the estimated vitamin D intake from an average European diet was 3.8µg/d of total Vitamin D Equivalents: vitamin D3, vitamin D2 and 25(OH)D3, contributing about 71%, 2%, and 27%, respectively. Animal foods, fortified fats and spreads contributed most to total intakes. Literature suggests that 94-100% of Europeans aged ≥13y fail to meet the vitamin D reference intake of 10µg/d. About 98-100% of vitamin D-fortified food users and 99-100% of non-users in the UK and Netherlands consumed less than 10µg/d of vitamin D. About 1.2% of prepackaged foods and drinks were voluntary fortified with vitamin D, margarine and plant-based drinks providing most of the daily vitamin D. Encouraging fortification and other strategies may support closing the gap between current and recommended vitamin D intakes.

Effect of calcifediol and cholecalciferol on muscle function in postmenopausal women: a randomized controlled trial

Brief rationale: Limited evidence exists on calcifediol's effect on lower extremity function in postmenopausal women with osteoporosis or osteopenia.

MAIN RESULT

Calcifediol (20 µg/day) showed no greater benefit than vitamin D3 (3200 IU/day) or placebo. Significance of the paper: Findings do not support high-dose vitamin D3 or calcifediol for improving lower extremity function.

PURPOSE

To test the effect of 20 µg/day of calcifediol compared with 3200 IU/day of vitamin D3 and placebo on lower extremity function in postmenopausal women with osteopenia or osteoporosis.

METHODS

This is a 3-arm double-blind RCT among postmenopausal women aged 50-70 years with serum 25(OH)D < 30 ng/mL, and a DXA-based diagnosis of osteopenia or osteoporosis. Participants were randomized to receive either daily 20 µg calcifediol, daily 3200 IU vitamin D3, or placebo. The primary endpoint was a composite measure of lower extremity function, assessed at baseline, 3, and 6 months, including four tests: gait speed, knee flexor and extensor strength, and repeated sit-to-stand test. The primary endpoint was the probability of success (improvement or maintenance from baseline) in any of the eight tests, four tests at 3 months and four tests at 6 months.

RESULTS

The trial enrolled 152 women (mean age, 61.0 years; mean serum 25(OH)D level, 23.4 ng/mL), and all but one woman completed all follow-up visits. Baseline characteristics, including the four tests of lower extremity function, were balanced across the three groups. The adjusted probability of success in any of the eight tests was 53.6% (95% confidence interval 47%, 60%) with calcifediol, 55.5% (50%, 61%) with vitamin D3, and 61.4% (55%, 67%) with placebo, without significant differences between treatment groups.

CONCLUSIONS

Our findings do not support supplementation with daily calcifediol or equivalent high-dose daily vitamin D3 for improving or maintaining lower extremity function among younger postmenopausal women (age 50-70) with osteopenia or osteoporosis, who were pre-selected for vitamin D insufficiency or deficiency (25(OH)D < 30 ng/mL; baseline mean 25(OH)D 23.4 ng/mL).

TRIAL REGISTRATION

Clinicaltrials.gov; NCT02527668; https://clinicaltrials.gov/ct2/show/NCT02527668.

Effect of cholecalciferol versus calcifediol on serum 25(OH)D concentrations: a systematic review with meta-analysis

BACKGROUND

Deficiency in vitamin D is widely prevalent around the world. Oral vitamin D supplementation is suggested for older adults to sustain appropriate 25-hydroxyvitamin D (25(OH)D) levels throughout the year. At present, cholecalciferol (vitamin D3) and ergocalciferol (vitamin D2) are the most commonly used compounds. Supplementation with calcifediol (25OHD3) rather than vitamin D itself should also be considered for the treatment. We performed a systematic review of the literature with a meta-analysis to assess the effects of cholecalciferol (vitamin D3) compared to calcifediol (25OHD3) on increasing serum 25(OH)D levels.

METHODS

A search of online databases was performed electronically for all relevant observational published population-based studies until November 2023, without geographical restrictions. We included studies that directly compared the effects of cholecalciferol and calcifediol on increasing concentrations of serum 25(OH)D. Only papers in English or French languages were considered. Records were screened and data were retrieved through a standardized extraction process.

RESULTS

Seventeen studies including 1575 participants were reviewed. Twelve intervention trials showed that, in spite of the dosage or the frequency of administration, calcifediol supplementation was more efficacious in raising serum 25(OH)D concentrations compared with cholecalciferol. Two studies showed that calcifediol and cholecalciferol were identically potent. According to three studies, cholecalciferol was more effective than calcifediol in raising 25(OH)D concentrations. A meta-analysis including randomized controlled trials (RCTs) and non-randomized trials revealed that calcifediol supplementation had a better impact on elevating serum 25(OH)D concentrations compared with the effect of cholecalciferol.

CONCLUSION

This meta-analysis suggests that calcifediol is more effective in increasing serum 25(OH)D concentrations compared to cholecalciferol. Consequently, calcifediol may emerge as the preferred option for supplementation.

Retrospective real world study on vitamin D supplementation: Looking for the most effective molecule and its frequency of use

BACKGROUND & AIMS

There is still uncertainty regarding the optimal serum levels 25-Hydroxy-vitamin D [25(OH)D] and the most effective supplementation strategies, including the choice of molecule and its dosing frequency. The aim of the study is to compare the effects of calcifediol versus two different frequencies of cholecalciferol administration on vitamin D supplementation, and to identity the key parameters that predict response to treatment.

METHODS

This retrospective, real-world cohort study included 105 patients, who were divided into three groups. Group 1 (n = 21) received cholecalciferol 50,000 international units (UI) once a month, Group 2 (n = 27) received cholecalciferol 25,000 UI every two weeks, and Group 3 (n = 57) received calcifediol 0.266 mg (mg) once a month. The primary outcome measured was the delta increase in 25(OH)D levels after 6 months of treatment, compared to pre-treatment levels.

RESULTS

The study revealed a significant greater delta increase in 25(OH)D levels in Group 1, which received cholecalciferol 50,000 IU once a month, compared to the other two groups. However, multiple regression analysis indicated that neither the type of molecule nor the frequency of administration independently influenced the treatment outcome. Only pre-treatment serum 25(OH)D levels were found to significantly affect the outcome. Based on the receiver operating characteristic curve, serum 25(OH)D levels below 19.5 ng/dL were predictive of a doubling of pre-treatment values, with high sensitivity and specificity.

CONCLUSION

Pre-treatment serum 25(OH)D levels are valuable for selecting patients who should undergo supplementation. This finding suggests the importance of tailoring therapy according to the degree of vitamin D deficiency.

Vitamin D: are all compounds equal?

Vitamin D is a pre-hormone essential for maintaining mineral homeostasis and also plays significant roles in bone, cardiovascular and renal health. Vitamin D deficiency is prevalent in the general population, and even more so in chronic kidney disease (CKD) patients, in which it contributes to the development and progression of mineral and bone disorder. The landscape of vitamin D treatment has evolved, with several analogues now available, each possessing distinct pharmacokinetic and pharmacodynamic properties, efficacies and safety profiles. This diversity allows for tailored, personalized approaches to treatment in CKD patients. This review aims to provide a comprehensive overview of vitamin D, including its natural sources and metabolism, and examines the main available pharmacological vitamin D products. Particular emphasis is placed on their application in CKD management, highlighting how these compounds can be strategically used to address both vitamin D deficiency and secondary hyperparathyroidism, while also acknowledging the ongoing debate about their impact on bone health and other clinical outcomes.

Vitamin D: Beyond Traditional Roles-Insights into Its Biochemical Pathways and Physiological Impacts

Background: It is true that vitamin D did not earn its title as the "sunshine vitamin" for nothing. In recent years, however, there has been a shift in the perception surrounding vitamin D to a type of hormone that boasts countless bioactivities and health advantages. Historically, vitamin D has been known to take care of skeletal integrity and the calcium-phosphorus balance in the body, but new scientific research displays a much larger spectrum of actions handled by this vitamin. Materials and Methods: A systematic literature search was performed using the following electronic databases: PubMed, Scopus, Web of Science, Embase, and Cochrane Library. Results: Many emerging new ideas, especially concerning alternative hormonal pathways and vitamin D analogs, are uniformly challenging the classic "one hormone-one receptor" hypothesis. To add more context to this, the vitamin D receptor (VDR) was previously assumed to be the only means through which the biologically active steroid 1,25-dihydroxyvitamin D3 could impact the body. Two other molecules apart from the active hormonal form of 1,25(OH)2D3 have gained interest in recent years, and these have reinvigorated research on D3 metabolism. These metabolites can interact with several other nuclear receptors (like related orphan receptor alpha-RORα, related orphan receptor gamma-RORγ, and aryl hydrocarbon receptor-AhR) and trigger various biological responses. Conclusions: This paper thus makes a case for placing vitamin D at the forefront of new holistic and dermatological health research by investigating the potential synergies between the canonical and noncanonical vitamin D pathways. This means that there are now plentiful new opportunities for manipulating and understanding the full spectrum of vitamin D actions, far beyond those related to minerals.

Daily or intermittent vitamin D supplementation in patients with or at risk of osteoporosis: Position statement from the GRIO

Advantages and disadvantages of intermittent versus daily vitamin D supplementation especially in adults with or at risk of osteoporosis are discussed by the Osteoporosis Research and Information Group (GRIO). The analysis of the literature suggests that intermittent long-term high doses vitamin D supplementation (such as 60,000IU/month or more), may increase the risk of falls, fracture and premature death in certain populations, while daily doses of 800-1000IU with calcium decrease falls and non-vertebral fractures in the elderly with vitamin D deficiency. In patients with or at risk of osteoporosis we hence recommend measuring the 25(OH)D concentration prior to supplementation and to provide vitamin D supplementation (with optimization of calcium intake if needed) to obtain a concentration between 30 and 60ng/mL. We recommend the use of an initial loading dose, especially in those who need a quick repletion of vitamin D store (symptoms of osteomalacia and/or 25(OH)D concentration <12ng/mL, patients eligible for treatment with potent antiresorptive therapy), followed by a maintenance dose. A daily supplementation should be the rule when possible. When daily forms are however not available or not reimbursed, we recommend, like other experts, to continue using intermittent dosing with the smallest available dose (≤50,000IU) and the shortest interval between doses as a stopgap until reimbursement or adequate daily pharmaceutical forms (pills or soft capsules of 1000, 2000IU) are available.

Exploring the link between fat-soluble vitamins and aging-associated immune system status: a literature review

The importance of vitamin D for a well-functioning immune system is becoming increasingly evident. Nevertheless, the other fat-soluble vitamins A, E and K also seem to play a central role regarding the adequate function of immune cells and to counteract excessive immune reactions and inflammatory processes. However, recognizing hidden hunger, particularly micronutrient deficiencies in vulnerable groups like the elderly, is crucial because older adults often lack sufficient micronutrients for various reasons. This review summarizes the latest findings on the immune modulating functions of fat-soluble vitamins in a physiological and pathophysiological context, provides a graphical comparison of the Recommended Daily Allowances between Deutschland, Austria, Confoederatio Helvetica (D-A-CH; eng. GSA, Germany, Switzerland, Austria), Deutsche Gesellschaft für Ernährung (DGE; eng. German Nutrition Society) and National Institutes of Health (NIH) across all age groups and, in particular, addresses the question regarding the benefits of supplementation of the respective micronutrients for the aging population of industrialized nations to strengthen the immune system. The following review highlights the importance of fat-soluble vitamins A, D, E and K which play critical roles in maintaining immune system function and, in some cases, in preventing excessive immune activation. Therefore, a better understanding of the relevance of adequate blood levels and consequently potential supplementation strategies may contribute to the prevention and management of infectious diseases as well as better overall health of the elderly.

Enhancing the Design of Nutrient Clinical Trials for Disease Prevention-A Focus on Vitamin D: A Systematic Review

OBJECTIVES

This systematic review (SR) highlights principles for nutrient clinical trials and explore the diverse physiological functions of vitamin D beyond its traditional role in the musculoskeletal system related to clinical study designs.

BACKGROUND

Thousands of published research articles have investigated the benefits of vitamin D (a nutrient example taken in this SR) beyond the musculoskeletal system, including the immune, pulmonary, and cardiovascular systems; pregnancy; autoimmune disorders; and cancer. They illustrated vitamin D's molecular mechanisms, interactions, and genomic and nongenomic actions.

METHODS

This SR was designed to identify shortcomings in clinical study designs, statistical methods, and data interpretation that led to inconsistent findings in vitamin D-related publications. SR also highlights examples and insights into avoiding study design errors in future clinical studies, including randomized controlled clinical trials (RCTs). The SR adheres to the latest PRISMA statement, guidelines, and the PICOS process.

RESULTS

Inappropriate or flawed study designs were frequent in clinical trials. Major failures discussed here include too short clinical study duration, inadequate or infrequent doses, insufficient statistical power, failure to measure baseline and achieved levels, and recruiting vitamin D-sufficient participants. These design errors have led to misleading interpretations. Thus, conclusions from such studies should not be generalized or used in guidelines, recommendations, or policymaking.

CONCLUSION

Adequately powered epidemiological studies and RCTs with sufficient vitamin D and duration in individuals with vitamin D deficiency reported favorable clinical outcomes, enriching the literature, enabling to understand its physiology and mechanisms. Proper study designs with rigorous methodologies and cautious interpretation of outcomes are crucial in advancing the nutrient field. The principles discussed apply not only to vitamin D, but also other micro-nutrients and nutraceutical research. Adhering to them enhances the credibility and reliability of clinical trials, SRs, and meta-analysis outcomes. The study emphasizes the importance of focused, hypothesis-driven, well-designed, statistically powered RCTs to explore the diverse benefits of nutrients, conducted in index nutrient deficient participants, and avoidance of study design errors. Findings from such studies should be incorporated into clinical practice, policymaking, and public health guidelines, improving the health of the nation and reducing healthcare costs.

A narrative review focusing on randomized clinical trials of vitamin D supplementation for COVID-19 disease

Current evidence is inconsistent on whether vitamin D supplementation can prevent COVID-19 infection or improve its clinical outcomes. To better understand and look into the issue, we went through the background knowledge of COVID-19 and vitamin D, searched in Pubmed [by using key words in the title containing "randomized clinical trial", "COVID-19", and "vitamin D (25-hydroxyvitamin D, or cholecalciferol, or calcidiol, or calcifediol) supplementation"] for publications of studies on vitamin D/supplementation in COVID-19 patients, especially those about the randomized clinical trials (RCTs). After reviewing these papers, we did a short background review of vitamin D and the pathophysiology of COVID-19, summarized the key features of the 25 RCTs in text and tabulated in a table of some of the features, commented, compared and discussed the differences between RCTs (for example, change the serum 25-hydroxyvitamin D concentration from nmol/L to ng/mL, making the comparison easier). The take-home question of the review is that serum 25-hydroxyvitamin D concentration is an important indicator of the supplementation effect of vitamin D correction but may not be reliable in predicting the supplementation effect on the clinical outcomes of COVID-19.

Different vitamin D supplementation strategies impact serum vitamin D concentrations and the mRNA expression of genes related to vitamin D metabolism, mitochondria respiration, redox balance, and immune system in weanling piglets

This study compared the effects of different vitamin D supplementation strategies to pre- and postweaning piglets on vitamin D metabolism and health-related parameters. Sixty Yorkshire-Landrace × Duroc suckling piglets were selected at the first day of age and randomly assigned to one of two vitamin D supplementation strategies (n = 30 pigs per treatment): CTR-oral saline at days 2, 8, and 21 of age and, from weaning (day 21), in-feed supplementation with 2,000 IU of vitamin D as cholecalciferol; and VD-oral 25-hydroxycholecalciferol (25(OH)D3) solution at days 2, 8, and 21 of age plus 15-min exposure to UVB light every second day from day 14 until day 21 and, from weaning, in-feed supplementation with 2,000 IU of vitamin D as 25(OH)D3. Piglets were slaughtered (n = 10 pigs per treatment/day) at days 21 (before start in-feed experimental diets), and 28 and 35 and blood and tissues samples (jejunum, liver, and kidney) were collected. Body weight (BW), concentrations of serum 25(OH)D3 and jejunum, liver, and kidney mRNA expression of genes related to vitamin D, antioxidant system, and immune defense were measured. Body weight was not affected by treatments (P ≥ 0.34). Serum 25(OH)D3 concentrations were greater for VD piglets at day 21, 28, and 35 (P < 0.01). No effect of treatment was detected (P ≥ 0.14) for mRNA expression in the jejunum mucosa. In the liver of VD piglets, mRNA expressions of genes related to the antioxidant system were lower at day 21 (NDUFB2) and at day 28 (BNIP3, GPX4, and MSRA) (P ≤ 0.10). The mRNA analysis in kidney during the overall period detected higher expression of genes related to the mitochondria oxidative phosphorylation (COX17, NDUFB2, and NDUFB6) in VD groups compared with CTR (P ≤ 0.09). The expression of CYP27B1 in kidney was higher at day 28 and CYP24A1 was lower at day 21 but higher at day 35 for VD animals. In conclusion, during the preweaning period, dietary 25(OH)D3 supplementation combined with UVB exposure was effective in increasing serum 25(OH)D3 concentrations at weaning, whereas in the postweaning period, dietary 25(OH)D3 supplementation at 2,000 IU/kg was more efficient then dietary cholecalciferol at similar levels. The overall results indicate that 2,000 IU of vitamin D/kg of diet, independently of source, may be enough to improve the vitamin D status of postweaning piglets. However, the use of dietary 25(OH)D3 may promote a better modulation of vitamin D metabolism and redox balance.

The Role of Vitamin D Deficiency in Hepatic Encephalopathy: A Review of Pathophysiology, Clinical Outcomes, and Therapeutic Potential

Hepatic encephalopathy (HE) is a neuropsychiatric condition frequently associated with cirrhosis and portosystemic shunting (PSS). It imposes a significant clinical and economic burden, with increasing attention toward identifying modifiable factors that could improve outcomes. Emerging evidence suggests that vitamin D deficiency (VDD), prevalent in patients with cirrhosis, may contribute to the development and severity of HE. This review explores the association between VDD and HE by analyzing the underlying pathophysiology, including oxidative stress, ammonia accumulation, and impaired hepatic function. Additionally, we summarize recent studies highlighting the correlation between low serum 25-hydroxy vitamin D (25-OHD) levels and worsening grades of HE. Despite strong observational data, interventional studies on vitamin D (VD) supplementation for HE remains limited. Current evidence suggests that VD's antioxidant properties may alleviate oxidative stress in HE, with potential benefits in mitigating disease severity. Future research should focus on longitudinal studies and randomized controlled trials to evaluate the clinical impact of VD supplementation on HE outcomes and explore VD's role in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) procedures. Understanding the therapeutic potential of VD could lead to improved management strategies for HE and cirrhotic patients at large.

Efficacy and Safety of Weekly Calcifediol Formulations (75 and 100 µg) in Subjects with Vitamin D Deficiency: A Phase II/III Randomised Trial

BACKGROUND/OBJECTIVE

Optimal vitamin D levels are required for bone health and proper functionality of the nervous, musculoskeletal and immune systems. The objective of this study was to assess the efficacy and safety profiles of new weekly calcifediol formulations with the potential to improve adherence and outcome.

METHODS

A Phase II-III, double-blind, randomized, multicentre trial (EudraCT 2020-001099-14 and NCT04735926). Subjects were randomized 2:2:1 to calcifediol 75 µg, 100 µg and placebo. 25(OH)D levels were measured at 4, 16, 24, 32 and 52 weeks. The main outcome was the percentage of subjects who achieved a response defined as 25(OH)D levels ≥20 ng/mL and/or ≥30 ng/mL at week 16.

RESULTS

398 subjects (51.1 ± 15.96 years, 74.2% females, 98.7% Caucasian) with plasma 25(OH)D levels between 10 and 20 ng/mL were randomized. A total of 376 subjects completed 16 weeks of treatment, and 355 subjects completed the study. Six patients withdrew due to an adverse event, all unrelated to treatment. At week 16, 93.6% and 74.4% of subjects receiving calcifediol 75 µg achieved response levels of ≥20 ng/mL and ≥30 ng/mL, respectively. The calcifediol 100 µg group showed 98.7% and 89.9% of responders for ≥20 ng/mL and ≥30 ng/mL, respectively. Both calcifediol groups showed superiority over placebo at each response level at all time points analyzed (p < 0.0001). Calcifediol treatments increased 25(OH)D levels from baseline to week 24 and remained stable thereafter. The frequency of treatment-emergent adverse events was balanced between groups.

CONCLUSIONS

New weekly calcifediol 75 and 100 µg formulations showed an effective and sustained response with a good long-term safety profile.

Impact of BMI on serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D with calcifediol supplementation in young adults: a longitudinal study

BACKGROUND

High body mass index (BMI) is a risk factor for vitamin D deficiency. The rise in serum 25-hydroxyvitamin D [25(OH)D] concentrations following cholecalciferol supplementation is suboptimal, owing to adipose tissue sequestration and/or volumetric dilution. Calcifediol is a proven potent oral alternative for vitamin D supplementation, but whether BMI adversely affects its efficacy in raising 25(OH)D concentrations, is not well known.

MATERIAL AND METHODS

Adults with serum concentrations of 25(OH)D < 30 ng/mL were recruited and stratified as normal, overweight, or obese using WHO criteria. Baseline evaluation included 25(OH)D, parathyroid hormone (PTH), and total 1,25-dihydroxyvitamin D [1,25(OH)2D] based on BMI category (n = 883). A subset of participants was supplemented with 50 µg calcifediol (n = 193) and assessed for the rise in serum concentrations of 25(OH)D at 3- and 6-months following supplementation.

RESULTS

Participants were stratified as obese (11.2%), overweight (32.1%), or normal weight (56.7%). There were no significant baseline differences in serum concentrations of 25(OH)D among the groups (13.1 ± 6.4 vs 12.8 ± 6.8 vs 11.6 ± 6.6 ng/mL, p = 0.62). Similarly, PTH or 1,25(OH)2D concentrations were not different among the groups. On follow-up, 25(OH)D concentrations increased in all three groups at 3 and 6 months from baseline. The increase in 25(OH)D was 74.4 ng/mL (IQR 35.3-115.3) in obese, followed by overweight 62.2 ng/mL (18.1-98.7) and normal weight groups 47.1 ng/mL (17.5-89.7) at 3 months. 1,25(OH)2D also increased in all groups, without any significant intergroup differences (p > 0.05).

CONCLUSION

BMI does not impede the rise in 25(OH)D concentrations following supplementation with calcifediol in young adults with vitamin D deficiency.

Consensus Statement on Vitamin D Status Assessment and Supplementation: Whys, Whens, and Hows

The 6th International Conference, "Controversies in Vitamin D," was convened to discuss controversial topics, such as vitamin D metabolism, assessment, actions, and supplementation. Novel insights into vitamin D mechanisms of action suggest links with conditions that do not depend only on reduced solar exposure or diet intake and that can be detected with distinctive noncanonical vitamin D metabolites. Optimal 25-hydroxyvitamin D (25(OH)D) levels remain debated. Varying recommendations from different societies arise from evaluating different clinical or public health approaches. The lack of assay standardization also poses challenges in interpreting data from available studies, hindering rational data pooling and meta-analyses. Beyond the well-known skeletal features, interest in vitamin D's extraskeletal effects has led to clinical trials on cancer, cardiovascular risk, respiratory effects, autoimmune diseases, diabetes, and mortality. The initial negative results are likely due to enrollment of vitamin D-replete individuals. Subsequent post hoc analyses have suggested, nevertheless, potential benefits in reducing cancer incidence, autoimmune diseases, cardiovascular events, and diabetes. Oral administration of vitamin D is the preferred route. Parenteral administration is reserved for specific clinical situations. Cholecalciferol is favored due to safety and minimal monitoring requirements. Calcifediol may be used in certain conditions, while calcitriol should be limited to specific disorders in which the active metabolite is not readily produced in vivo. Further studies are needed to investigate vitamin D effects in relation to the different recommended 25(OH)D levels and the efficacy of the different supplementary formulations in achieving biochemical and clinical outcomes within the multifaced skeletal and extraskeletal potential effects of vitamin D.

Vitamin D: Analytical Advances, Clinical Impact, and Ongoing Debates on Health Perspectives

BACKGROUND

Vitamin D, acknowledged since the 1930s for its role in preventing rickets, gained additional prominence in relation to fragility fracture prevention in the late 1980s. From the early 2000s, connections between vitamin D deficiency and extra-skeletal pathologies emerged, alongside increased awareness of widespread deficits. This prompted crucial debates on optimal serum concentrations, expected to conclude when the outcomes of high-dose supplementation randomized controlled trials were available. Skepticism arose with inconclusive results from these trials.

CONTENT

This review begins with an exploration of vitamin D metabolism, followed by a detailed description of the measurement of vitamin D metabolites and the crucial role of standardization. Subsequent sections focus on the association of vitamin D with bone health and explore the extra-skeletal effects. The review concludes with a comprehensive discussion on the definition of vitamin D status and its implications for supplementation.

SUMMARY

Despite standardization efforts, assay variations and challenges still exist, especially in specific patient groups. Vitamin D supplementation has a significant impact on bone metabolism and optimal vitamin D status improves the efficacy of antiresorptive drugs such as bisphosphonates. The extra-skeletal effects of vitamin D remain debated, but may include potential benefits in conditions such as respiratory infections and cancer mortality, particularly in deficient individuals. The definition of vitamin D sufficiency is nuanced, especially when variations in population groups and analytical methods are taken into account. Despite ongoing debates and recent mega-trials tempering enthusiasm, vitamin D remains a complex and essential element in human health. Further research is needed to clarify its role in various health outcomes and guide supplementation strategies.

Real-world effectiveness and safety of combined calcium 600 mg and cholecalciferol 2000 IU for treating vitamin d deficiency: Results from a nationwide study with focus in osteoporosis

Introduction

Treatment of calcium (Ca) and vitamin D (VD) deficiency (VDD) is crucial for health, especially in bone conditions, such as low bone mineral density (BMD) and osteoporosis. Despite updates in clinical guideline recommendations, no studies have evaluated the efficacy and safety of administering 2000 IU of cholecalciferol combined with calcium. Thus, the main objective of this study was to evaluate VD levels following treatment with Ca 600 mg/ cholecalciferol 2000 IU in real-life clinical practice.

Methods

This multicenter, retrospective, observational study included 302 adult patients receiving Ca 600 mg/D3 2000 IU orodispersible tablets, daily for ≥24 weeks. The primary outcome was 25-hydroxivitamin D [25(OH)D] serum levels following treatment. Key secondary outcomes included changes in serum 25(OH)D levels and other bone metabolism (BM) parameters, safety and tolerability. The protocol was approved by a Research Ethics Committee.

Results

285 patients were evaluated (mean age [SD]: 67.4 [12.6] years old; 88.4 % women; basal serum 25(OH)D: 20.0 [8.6] ng/mL); 80.7 % reported previous history of osteoporosis/low BMD (osteopenia) and 37.2 % had received other Ca/VD prior to start study treatment. Median treatment duration was 38.5 weeks [range 24.0-82.4]. Overall, 94.4 % of patients increased serum 25(OH)D following treatment to a mean of 36.3 [11.8] ng/mL (p < 0.001 vs. baseline). Patients with basal VDD, significantly increased serum 25(OH)D to a mean over 30 ng/mL; no significant change found in repleted patients (basal 25(OH)D level ≥ 30 ng/mL). PTH was significantly reduced after treatment, with no clinically relevant effect on serum Ca or phosphate. Three non-serious treatment-emergent adverse events were reported. A post-hoc analysis on osteoporotic patients revealed virtually identical results in this population.

Conclusion

Treatment with Ca 600 mg/cholecalciferol 2000 IU for at least 24 weeks is effective and safe, especially in osteoporosis. Patients with VDD significantly increase plasma 25(OH)D to optimal range for bone health, with no clinically relevant changes on other bone metabolism parameters other than reducing secondary hyperparathyroidism. The magnitude of 25(OH)D increase directly correlates with the severity of VDD, with no effect in basally repleted patients.

Optimisation of vitamin D status in global populations

Vitamin D is important for musculoskeletal health. Concentrations of 25-hydroxyvitamin D, the most commonly measured metabolite, vary markedly around the world and are influenced by many factors including sun exposure, skin pigmentation, covering, season and supplement use. Whilst overt vitamin D deficiency with biochemical consequences presents an increased risk of severe sequelae such as rickets, osteomalacia or cardiomyopathy and usually warrants prompt replacement treatment, the role of vitamin D supplementation in the population presents a different set of considerations. Here the issue is to keep, on average, the population at a level whereby the risk of adverse health outcomes in the population is minimised. This position paper, which complements recently published work from the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases, addresses key considerations regarding vitamin D assessment and intervention from the population perspective. This position paper, on behalf of the International Osteoporosis Foundation Vitamin D Working Group, summarises the burden and possible amelioration of vitamin D deficiency in global populations. It addresses key issues including screening, supplementation and food fortification.

Effect of 2 Years of Monthly Calcifediol Administration in Postmenopausal Women with Vitamin D Insufficiency

BACKGROUND

We assessed the long-term (24 months) efficacy and safety of monthly calcifediol (0.266 mg) in the correction and maintenance of total 25(OH)D levels in postmenopausal women with basal values <30 ng/mL.

METHODS

We initially enrolled 45 consecutive patients during the period September 2019-September 2020. After an initial visit, patients were instructed to return at 3, 6, 9, 12 and 24 months for measuring serum total 25(OH)D, ionised calcium, creatinine and isoenzyme of alkaline phosphatase (bALP). Here, we report only the per-protocol analysis, because the COVID-19 pandemic precluded adherence to the scheduled visits for some patients.

RESULTS

The patients' mean age was 62.4 ± 9.0 years. Mean basal 25(OH)D levels were 20.5 ± 5.3 ng/mL. There was a continuous increase of mean 25(OH)D values (p for trend < 0.001). However, mean values at month 24 (36.7 ± 15.9) were not significantly different in respect to values at month 12 (41.2 ± 11.18). At 24 months, only 1 out 19 patients had a value <20 ng/mL. There was a significant decrease with time of mean values of bALP (p < 0.0216), with no significant changes between 12 and 24 months. No significant changes were observed as far as ionised calcium or creatinine were concerned.

CONCLUSIONS

The long-term administration of calcifediol maintains stable and sustained 25(OH)D concentrations, with no safety concerns.

Safety and effects of calcifediol 0.266 milligrams soft capsules monthly and cholecalciferol 25000 international units monthly in osteoporotic women undergoing therapy with alendronate: a cross-sectional study

BACKGROUND

The role of vitamin D in human physiology is a topic of great interest for the scientific community in the last decades. The common target for all clinicians is to improve its status in order to prevent several pathological conditions.

METHODS

The aim of our study was to evaluate the safety and the efficacy of both calcifediol and cholecalciferol in combination with alendronate in osteoporotic women. A homogeneous population of 300 postmenopausal osteoporotic women was selected for this study. 150 women were administered with alendronate 70 mg combined with clacifediol 0.266 mg soft capsules monthly. The other half (other 150 women) were administered with alendronate 70 mg combined with cholecalciferol 25000 IU monthly. First follow-up was after 4 months and second follow-up after 12 months.

RESULTS

No case of toxicity was detected throughout the study in any patient. In regards to increase of vitamin D serum level, after four months supplementation calcifediol is 1.29 fold more effective than cholecalciferol while after 12 months of supplementation calcifediol is 2.32 fold more effective compared to cholecalciferol.

CONCLUSIONS

In our study calcifediol showed to be as safe as cholecalciferol and more effective than cholecalciferol in order to increase vitamin D serum level after four and 12 months of supplementation when supplementation is combined with alendronate 70 mg in osteoporotic women.

Accumulated LPS induced by colitis altered the activities of vitamin D-metabolizing hydroxylases and decreased the generation of 25-hydroxyvitamin D

It is generally accepted that low vitamin D (VD) levels are associated with a high prevalence factor for Inflammatory bowel disease (IBD). IBD patients have observed higher levels of lipopolysaccharide (LPS), ALT, and AST than healthy people. Gut-derived LPS causes inflammatory injury in the liver and kidney. The VD-metabolizing mechanism is involved in the liver and kidney, which means IBD might impact VD metabolism. However, whether IBD affects VD metabolism has not been studied. In vitro LPS resulted in decreased CYP2R1 in liver cells as well as decreased CYP27B1 and increased CYP24A1 in kidney cells, revealing that LPS changed the activities of several hydroxylases. Mice with acute colitis had an increased LPS in serum and liver with mild hepatic injuries, while mice with chronic colitis had a significant elevation of LPS in serum, liver, and kidney with hepatorenal injuries. Thus, the liver hydroxylase for VD metabolism would be the first to be affected in IBD. Consequently, serum 25-hydroxyvitamin D declined dramatically with a significant elevation of 24,25-dihydroxyvitamin D and 1,24,25-trihydroxyvitamin D. Unchanged serum levels of 1,25-dihydroxyvitamin D might be the result of other factors in vivo. In acute colitis, a small dosage (4 IU/day) of cholecalciferol could protect the colon, decrease the serum level of LPS, and finally increase serum 25-hydroxyvitamin D. However, this improvement of cholecalciferol was fading in chronic colitis. These results suggested that VD supplementations for preventing and curing IBD in the clinic should consider hepatorenal hydroxylases and be employed as soon as possible for a better outcome.

Discordant Health Implications and Molecular Mechanisms of Vitamin D in Clinical and Preclinical Studies of Prostate Cancer: A Critical Appraisal of the Literature Data

Clinical and preclinical studies have provided conflicting data on the postulated beneficial effects of vitamin D in patients with prostate cancer. In this opinion piece, we discuss reasons for discrepancies between preclinical and clinical vitamin D studies. Different criteria have been used as evidence for the key roles of vitamin D. Clinical studies report integrative cancer outcome criteria such as incidence and mortality in relation to vitamin D status over time. In contrast, preclinical vitamin D studies report molecular and cellular changes resulting from treatment with the biologically active vitamin D metabolite, 1,25-dihydroxyvitamin D3 (calcitriol) in tissues. However, these reported changes in preclinical in vitro studies are often the result of treatment with biologically irrelevant high calcitriol concentrations. In typical experiments, the used calcitriol concentrations exceed the calcitriol concentrations in normal and malignant prostate tissue by 100 to 1000 times. This raises reasonable concerns regarding the postulated biological effects and mechanisms of these preclinical vitamin D approaches in relation to clinical relevance. This is not restricted to prostate cancer, as detailed data regarding the tissue-specific concentrations of vitamin D metabolites are currently lacking. The application of unnaturally high concentrations of calcitriol in preclinical studies appears to be a major reason why the results of preclinical in vitro studies hardly match up with outcomes of vitamin D-related clinical studies. Regarding future studies addressing these concerns, we suggest establishing reference ranges of tissue-specific vitamin D metabolites within various cancer entities, carrying out model studies on human cancer cells and patient-derived organoids with biologically relevant calcitriol concentrations, and lastly improving the design of vitamin D clinical trials where results from preclinical studies guide the protocols and endpoints within these trials.

Extended-Release Calcifediol: A Data Journey from Phase 3 Studies to Real-World Evidence Highlights the Importance of Early Treatment of Secondary Hyperparathyroidism

BACKGROUND

Early secondary hyperparathyroidism (SHPT) diagnosis and treatment are crucial to delay the progression of SHPT and related complications, in particular, cardiovascular events and bone fractures. Extended-release calcifediol (ERC) has been developed for the treatment of SHPT in patients with stage 3/4 chronic kidney disease (CKD) and vitamin D insufficiency (VDI).

SUMMARY

This review compares baseline characteristics and treatment responses of SHPT patients receiving ERC in phase 3 studies with those treated with ERC in a real-world study. Mean ± standard deviation baseline parathyroid hormone (PTH) levels were 147 ± 56 pg/mL and 148 ± 64 pg/mL in the phase 3 ERC cohorts, and 181 ± 98 pg/mL in the real-world study. Other baseline laboratory parameters were consistent between the clinical and real-world studies. ERC treatment increased 25-hydroxyvitamin D (25(OH)D) and significantly reduced PTH levels, regardless of baseline CKD stage, in all studies. In the pooled phase 3 per-protocol populations, 74% of the ERC cohort were uptitrated to 60 μg/day after 12 weeks at 30 μg/day, 97% attained 25(OH)D levels ≥30 ng/mL, and 40% achieved ≥30% PTH reduction. Despite a much lower rate of uptitration in the real-world study, 70% of patients achieved 25(OH)D levels ≥30 ng/mL, and 40% had a ≥30% reduction in PTH.

KEY MESSAGES

These data establish a "continuum" of clinical and real-world evidence of ERC effectiveness for treating SHPT, irrespective of CKD stage, baseline PTH levels, and ERC dose. This evidence supports early treatment initiation with ERC, following diagnosis of SHPT, VDI, and stage 3 CKD, to delay SHPT progression.

Effect of 2 dosages of prepartum cholecalciferol injection on blood minerals, vitamin D metabolites, and milk production in multiparous dairy cows: A randomized clinical trial

The objective of the present study was to evaluate the effect of 2 dosages of prepartum cholecalciferol injection on blood minerals, vitamin D metabolites, and milk production. Cows entering their second or greater lactation (n = 158) were randomly assigned to a control group (CON) or one of 2 treatment groups receiving either 6 × 106 IU (6VitD) or 12 × 106 IU (12VitD) cholecalciferol intramuscularly on d 275 ± 1.2 (SD) of gestation. Concentrations of serum total Ca (tCa), phosphate, and Mg were determined on 1, 2, 3, 5, 7, and 10 d in milk (DIM). For a subsample of 30 cows entering the third lactation (n = 10/group), these samples were analyzed for cholecalciferol, 25-hydroxycholecalciferol (25-OHD3), and 24,25-dihydroxycholecalciferol (24,25-[OH]2D3). In these cows, we also determined 1,25-dihydroxycholecalciferol (1,25-[OH]2D3), the biologically most active metabolite, on 1, 2, 3, and 5 DIM. Repeated measures ANOVA was performed to evaluate the effect of different dosages of cholecalciferol on blood minerals, vitamin D metabolites, and milk yield over the first 5 test days after calving. Binary outcomes such as retained placenta and metritis were analyzed using a chi-squared test. Although the 12VitD treatment increased tCa concentrations on 1, 2, and 3 DIM compared with CON, administration of 6VitD increased tCa concentrations only on 1 DIM. Compared with CON cows and 6VitD cows, 12VitD cows had greater serum phosphate concentration during the first 10 DIM. Furthermore, 6VitD cows had greater serum phosphate concentrations compared with CON cows. On the contrary, 12VitD cows had lower serum Mg concentrations during the first 10 DIM compared with CON and 6VitD cows. Cholecalciferol was increased by the treatment and decreased quickly until 10 DIM. In respect to 25-OHD3, the 6VitD treatment resulted in a 4.1-fold increase in comparison to the CON group, while a 6.5-fold increase was observed in 12VitD animals. The vitamin D metabolite 24,25-(OH)2D3 increased linearly with 25-OHD3 serum levels, resulting in the highest concentrations in the 12VitD group. An increase of 1,25-(OH)2D3 until 3 DIM was observed in all cows. However, this rise was most pronounced in the CON group. The incidence of retained placenta was 1.9%, 11.5%, and 29.6%, and that of metritis was 11.5%, 15.4%, and 31.5% for CON, 6VitD, and 12VitD cows, respectively. Although none of the treated cows exerted clinical signs of hypocalcemia, one cow in CON incurred clinical hypocalcemia. Cows of the 12VitD group had a lower milk yield over the first 5 monthly test days compared with the control and 6VitD group (42.2 ± 0.5, 42.0, ± 0.5 and 40.7 ± 0.5 kg for control cows, 6VitD cows and 12VitD cows, respectively). Although no negative side effects were observed in 6VitD cows, we do not recommend the general application of 6 × 106 IU cholecalciferol before calving as positive effects on calcium homeostasis were marginal and restricted to the first DIM. The present findings confirm that the application of 12 × 106 IU cholecalciferol negatively affected milk production on this farm.

Synthesis of 25-Hydroxy-provitamin D3 by Direct Hydroxylation of Protected 7-Dehydrocholesterol

A new synthetic route to 25-hydroxy-provitamin D3 was elaborated. The synthesis consists of direct hydroxylation at C-25 of 7-dehydrocholesterol hetero Diels-Alder adducts. The adducts were prepared by [4 + 2] cycloaddition of azadienophiles to the steroidal diene. The hydroxylation reactions of adducts were carried out with different dioxiranes or with chromyl trifluoroacetate. The byproducts of these reactions were isolated and identified. The strengths and weaknesses of hydroxylation methods with different oxidizing agents were discussed.

Rickets Types and Treatment with Vitamin D and Analogues

The definition of "Vitamin D" encompasses a group of fat-soluble steroid compounds of different origins with similar chemical structures and the same biological effects. Vitamin D deficiency and/or a defect in the process of its synthesis or transport predispose individuals to several types of rickets. In addition to cholecalciferol, ergocalciferol, and vitamins D3 and D2, there are also active metabolites for the treatment of this condition which are commercially available. Calcitriol and aphacalcidiol are active metabolites that do not require the renal activation step, which is required with calcifediol, or hepatic activation. The purpose of this review is to summarize current approaches to the treatment of rickets for generalist physicians, focusing on the best vitamin D form to be used in each type, or, in the case of X-linked hypophosphatemic rickets (XLH), on both conventional and innovative monoclonal antibody treatments.

Vitamin D Supplementation: A Review of the Evidence Arguing for a Daily Dose of 2000 International Units (50 µg) of Vitamin D for Adults in the General Population

Vitamin D deficiency is considered a public health problem due to its worldwide high prevalence and adverse clinical consequences regarding musculoskeletal health. In addition, vitamin D may also be crucial for the prevention of certain extraskeletal diseases. Despite decades of intensive scientific research, several knowledge gaps remain regarding the precise definition of vitamin D deficiency and sufficiency, the health benefits of improving vitamin D status, and the required vitamin D intakes. Consequently, various societies and expert groups have released heterogeneous recommendations on the dosages for vitamin D supplementation. In this brief narrative review, we outline and discuss recent advances regarding the scientific evidence arguing for a daily vitamin D supplementation with 2000 international units (IU) (50 µg) of vitamin D3 to prevent and treat vitamin D deficiency. According to data from randomized controlled trials (RCTs), such a dose may improve some health outcomes and is sufficient to raise and maintain serum 25(OH)D concentrations above 50 nmol/L (20 ng/mL) and above 75 nmol/L (30 ng/mL) in >99% and >90% of the general adult population, respectively. According to large vitamin D RCTs, there are no significant safety concerns in supplementing such a dose for several years, even in individuals with an already sufficient vitamin D status at baseline. A daily vitamin D supplementation with 2000 IU (50 µg) may be considered a simple, effective, and safe dosage to prevent and treat vitamin D deficiency in the adult general population.

Highly selective whole-cell 25-hydroxyvitamin D3 synthesis using molybdenum-dependent C25-steroid dehydrogenase and cyclodextrin recycling

BACKGROUND

The global prevalence of vitamin D (VitD) deficiency associated with numerous acute and chronic diseases has led to strategies to improve the VitD status through dietary intake of VitD-fortified foods and VitD supplementation. In this context, the circulating form of VitD3 (cholecalciferol) in the human body, 25-hydroxy-VitD3 (calcifediol, 25OHVitD3), has a much higher efficacy in improving the VitD status, which has motivated researchers to develop methods for its effective and sustainable synthesis. Conventional monooxygenase-/peroxygenase-based biocatalytic platforms for the conversion of VitD3 to value-added 25OHVitD3 are generally limited by a low selectivity and yield, costly reliance on cyclodextrins and electron donor systems, or by the use of toxic co-substrates.

RESULTS

In this study, we used a whole-cell approach for biocatalytic 25OHVitD3 synthesis, in which a molybdenum-dependent steroid C25 dehydrogenase was produced in the denitrifying bacterium Thauera aromatica under semi-aerobic conditions, where the activity of the enzyme remained stable. This enzyme uses water as a highly selective VitD3 hydroxylating agent and is independent of an electron donor system. High density suspensions of resting cells producing steroid C25 dehydrogenase catalysed the conversion of VitD3 to 25OHVitD3 using either O2 via the endogenous respiratory chain or externally added ferricyanide as low cost electron acceptor. The maximum 25OHVitD3 titer achieved was 1.85 g L-1 within 50 h with a yield of 99%, which is 2.2 times higher than the highest reported value obtained with previous biocatalytic systems. In addition, we developed a simple method for the recycling of the costly VitD3 solubiliser cyclodextrin, which could be reused for 10 reaction cycles without a significant loss of quality or quantity.

CONCLUSIONS

The established steroid C25 dehydrogenase-based whole-cell system for the value-adding conversion of VitD3 to 25OHVitD3 offers a number of advantages in comparison to conventional oxygenase-/peroxygenase-based systems including its high selectivity, independence from an electron donor system, and the higher product titer and yield. Together with the established cyclodextrin recycling procedure, the established system provides an attractive platform for large-scale 25OHVitD3 synthesis.

Efficacy and Safety of Calcifediol in Young Adults with Vitamin D Deficiency: A Phase I, Multicentre, Clinical Trial-POSCAL Study

Vitamin D deficiency is highly prevalent, and recent evidence suggests a possible association between vitamin D deficiency and various health conditions. The aim of this study was to assess monthly calcifediol treatments for vitamin D deficiency (or biweekly, if the deficiency was severe) in a young adult population with no associated comorbidities. This multicentre phase I trial started with a four month open-label treatment phase (TP) that included 101 participants (65% women with mean age 29.8 years). Eighty-two percent of the subjects (79/96) achieved 25(OH)D levels within the target range (20-60 ng/mL) by the end of the TP, and they were subsequently randomised and subjected to a double-blind, placebo-controlled, five month follow-up phase (FP). At the end of the FP, 89% of participants maintained vitamin D levels of >20 ng/mL with calcifediol, versus 49% with placebo (p < 0.001). Subjects receiving monthly calcifediol during both phases (n = 32) maintained 25(OH)D levels >20 ng/mL, whereas those on the placebo during the FP (n = 38) exhibited deficiency levels of 25(OH)D by the end of the study. No clinically relevant changes in bone metabolism parameters or toxic 25(OH)D levels were observed, and no serious adverse events were reported throughout the study. Calcifediol is a safe and effective treatment for vitamin D deficiency in the young adult population, but long-term use may be required to sustain optimal 25(OH)D levels.

Dynamic Evaluation of Vitamin D Metabolism in Post-Bariatric Patients

BACKGROUND

findings from the previously conducted studies indicate altered regulatory mechanisms of calcium and vitamin D metabolism in obese patients and a role for bariatric surgery in regulating vitamin D metabolism; however, the available data is controversial and does not provide an adequate understanding of the subject.

METHODS

we evaluated serum parameters of vitamin D and mineral metabolism (vitamin D metabolites (25(OH)D3, 25(OH)D2, 1,25(OH)2D3, 3-epi-25(OH)D3, and 24,25(OH)2D3), vitamin D-binding protein (DBP), free 25(OH)D, fibroblast growth factor 23 (FGF-23), parathyroid hormone (PTH), total calcium, albumin, phosphorus, creatinine, magnesium) in 30 patients referred for bariatric surgery in comparison with 30 healthy volunteers of similar age, sex and baseline 25(OH)D3. Patients were also followed up with repeated laboratory assessments 3 months and 6 months after surgery. During the first 3 months, patients were prescribed high-dose cholecalciferol therapy (50,000 IU per week), with subsequent correction based on the results of the 3-month visit examination.

RESULTS

Preoperatively, patients with morbid obesity were characterized by a high prevalence of vitamin D deficiency (median 25(OH)D3 level 11.9 (6.8; 22.2) ng/mL), significantly lower levels of active vitamin D metabolite 1,25(OH)2D3 (20 (10; 37) vs. 39 (33; 50) pg/mL, p < 0.001), lower serum albumin-adjusted calcium levels (2.24 (2.20; 2.32) vs. 2.31 (2.25; 2.35) mmol/L, p = 0.009) and magnesium levels (0.79 (0.72; 0.82) vs. 0.82 (0.78; 0.85) mmol/L, p = 0.043) with simultaneous similar PTH levels (p = 0.912), and higher DBP levels (328 (288; 401) vs. 248 (217; 284) mg/L, p < 0.001). The 25(OH)D3 levels remained suboptimal (24.5 (14.7; 29.5) ng/mL at the 3-month visit and 17.9 (12.4; 21.0) ng/mL at the 6-month visit, p = 0.052) despite recommended high-dose cholecalciferol supplementation. Patients also demonstrated an increase in 1,25(OH)2D3 levels (38 (31; 52) pg/mL at the 3-month visit and 49 (29; 59) pg/mL at the 6-month visit, p < 0.001) without a change in PTH or calcium levels during the follow-up.

CONCLUSION

our results of a comprehensive laboratory evaluation of vitamin D status and mineral metabolism in patients undergoing bariatric surgery highlight the importance of improving current clinical guidelines, as well as careful monitoring and education of patients.

Efficacy of dietary vitamin D3 and 25(OH)D3 on reproductive capacities, growth performance, immunity and bone development in pigs

Vitamin D3 (Vit D3) and 25(OH)D3 are used as dietary sources of active vitamin D (1,25(OH)2D3) in pig husbandry. Although acting primarily on intestine, kidney and bone, their use in pig nutrition has shown a wide range of effects also in peripheral tissues. However, there is an ambiguity in the existing literature about whether the effects of Vit D3 and 25(OH)D3 differ in attributing the molecular and phenotypic outcomes in pigs. We searched Web of Science and PubMed databases concerning the efficacy of Vit D3 in comparison with 25(OH)D3 on pig physiology, i.e. reproductive capacities, growth performance, immunity and bone development. Dietary intake of Vit D3 or 25(OH)D3 did not influence the reproductive capacity of sows. Unlike Vit D3, the maternal intake of 25(OH)D3 significantly improved the growth performance of piglets, which might be attributed to maternally induced micronutrient efficiency. Consequently, even in the absence of maternal vitamin D supplementation, 25(OH)D3-fed offspring also demonstrated better growth than the offspring received Vit D3. Moreover, a similar superior impact of 25(OH)D3 was seen with respect to serum markers of innate and humoral immunity. Last but not least, supplements containing 25(OH)D3 were found to be more effective than Vit D3 to improve bone mineralisation and formation, especially in pigs receiving basal diets low in Ca and phosphorus. The insights are of particular value in determining the principal dietary source of vitamin D to achieve its optimum utilisation efficiency, nutritional benefits and therapeutic potency and to further improve animal welfare across different management types.

Vitamin D supplementation in a post-pandemic era: A narrative review

Vitamin D is a fat-soluble molecule referring to the different isoforms, ergocalciferol (D2) and cholecalciferol (D3). Its physiological functions include increasing calcium serum concentrations. 25-hydroxyvitamin D3 (25(OH)D) (Calcifediol), a non-active, circulating instant precursor is seen as a pre-hormone. Studies have shown that a deficiency in calcifediol is related to chronic conditions such as cardiovascular, musculoskeletal, immune system, neurological, and anti-neoplastic functions. Vitamin D supplementation has shown its benefit as prophylaxis and treatment during the coronavirus disease 2019 (COVID-19) pandemic and an increase in the prescribing of vitamin D supplementation has been observed. The intention of this review article is to provide guidance on the recommended dosage regimen as a prophylactic measure during COVID-19 and its use as a supplement in general. From this review article, it is clear that vitamin D has an important role to play not only in COVID-19 but also in various other health aspects of the human body.Contribution: This review article highlighted the role of vitamin D in managing vitamin D deficiency and its role as a supplement in the management of respiratory tract infections, especially COVID-19. This overview can assist physicians in optimising healthcare by optimised dosing recommendations and indications.

The Impact of Vitamin D Deficiency on Infants' Health

Vitamin D is an essential nutrient that plays a vital role in bone health and musculoskeletal development. The aim of this narrative review is to present up-to-date information about the impact of vitamin D deficiency (VDD) on the health status of infants in their first year of life. Vitamin D is indispensable for skeletal growth and bone health, and emerging research suggests that it may also have significant roles in maternal and fetal health. VDD affects a large proportion of infants according to current guidelines. However, its prevalence varies depending on geographic location, skin pigmentation, and the time of year. Based on current guidelines for normal vitamin D levels and recommended daily intake, studies suggest that VDD is a global health issue with potentially significant implications for those at risk, especially infants. Our understanding of the role of vitamin D has improved significantly in the last few decades. Systematic reviews and meta-analyses investigating the effect of vitamin D on preterm birth, low birth weight, anthropometric parameters, and health outcomes such as infectious diseases in infants, have found conflicting or inconsistent results. It is important to encourage further research to fill in these knowledge gaps and develop national or global strategies that ease the burden of VDD, especially in groups at risk.

Bariatric surgery and calcifediol treatment, Gordian knot of severe-obesity-related comorbidities treatment

Background

Obesity (OB) is a chronic metabolic disease with important associated comorbidities and mortality. Vitamin D supplementation is frequently administered after bariatric surgery (BS), so as to reduce OB-related complications, maybe including chronic inflammation.

Aim

This study aimed to explore relations between vitamin D metabolites and components of the inflammasome machinery in OB before and after BS and their relations with the improvement of metabolic comorbidities.

Patients and methods

Epidemiological/clinical/anthropometric/biochemical evaluation was performed in patients with OB at baseline and 6 months after BS. Evaluation of i) vitamin-D metabolites in plasma and ii) components of the inflammasome machinery and inflammatory-associated factors [NOD-like-receptors (NLRs), inflammasome-activation-components, cytokines and inflammation/apoptosis-related components, and cell-cycle and DNA-damage regulators] in peripheral blood mononuclear cells (PBMCs) was performed at baseline and 6 months after BS. Clinical and molecular correlations/associations were analyzed.

Results

Significant correlations between vitamin D metabolites and inflammasome-machinery components were observed at baseline, and these correlations were significantly reduced 6 months after BS in parallel to a decrease in inflammation markers, fat mass, and body weight. Treatment with calcifediol remarkably increased 25OHD levels, despite 24,25(OH)2D3 remained stable after BS. Several inflammasome-machinery components were associated with improvement in metabolic comorbidities, especially hypertension and dyslipidemia.

Conclusion

The beneficial effects of vitamin D on OB-related comorbidities after BS patients are associated with significant changes in the molecular expression of key inflammasome-machinery components. The expression profile of these inflammasome components can be dynamically modulated in PBMCs after BS and vitamin D supplementation, suggesting that this profile could likely serve as a sensor and early predictor of the reversal of OB-related complications after BS.

Calcium Homeostasis and Psychiatric Disorders: A Mendelian Randomization Study

Observational studies have investigated the impact of calcium homeostasis on psychiatric disorders; however, the causality of associations is yet to be established. Bidirectional Mendelian randomization (MR) analysis of calcium homeostasis hormones was conducted on nine psychiatric disorders. Calcium, serum 25-hydroxyvitamin D levels (25OHD), parathyroid hormone, and fibroblast growth factor 23 are the major calcium homeostasis hormones. The causality was evaluated by the inverse variance weighted method (IVW) and the MR Steiger test, while Cochran's Q test, the MR-Egger intercept test, funnel plot, and the leave-one-out method were used for sensitivity analyses. Bonferroni correction was used to determine the causative association features (p < 6.94 × 10-4). Schizophrenia (SCZ) was significantly associated with decreased 25OHD concentrations with an estimated effect of -0.0164 (Prandom-effect IVW = 2.39 × 10-7). In the Multivariable MR (MVMR) analysis adjusting for potentially confounding traits including body mass index, obesity, mineral supplements (calcium, fish oil, and vitamin D) and outdoor time (winter and summer), the relationship between SCZ and 25OHD remained. The genetically predicted autism spectrum disorder and bipolar disorder were also nominally associated with decreased 25OHD. This study provided evidence for a causal effect of psychiatric disorders on calcium homeostasis. The clinical monitoring of 25OHD levels in patients with psychiatric disorders is beneficial.

Calcifediol in the management of vitamin D deficiency-related skeletal and extraskeletal diseases: overview and clinical cases

As well as being essential for musculoskeletal health, vitamin D is involved in numerous other physiological processes. Poor vitamin D status is linked to a wide range of diseases, including cardiovascular disease, autoimmune conditions, pulmonary disorders and upper respiratory tract infections. While optimal target concentrations of serum 25-hydroxyvitamin D (25(OH)D) for health maintenance or therapeutic purposes are still the subject of debate, there is reasonable agreement that serum 25(OH)D levels <50 nmol/L (20 ng/mL) constitute vitamin D deficiency and that severe deficiency states (serum 25(OH)D levels <25-30 nmol/L ≈ 10-12 ng/mL) should be avoided. Main strategies to maintain or improve vitamin D status are food supplementation and therapeutic use of medicinal forms of vitamin D. In this review, we examine evidence that implicates vitamin D deficiency in diverse conditions in the clinical settings of endocrinology, rheumatology, pneumology and reproductive health. Cholecalciferol (vitamin D3) is the most frequently used vitamin D supplement worldwide, though calcifediol (25-hydroxyvitamin D3) has recently become more widely available. Calcifediol is one step closer than cholecalciferol in the metabolic pathway to biologically active vitamin D. Pharmacokinetic differences between these vitamin D metabolites confer putative advantages for calcifediol in certain clinical situations. The clinical use of calcifediol is explored more closely through case studies, which illustrate its adjunctive role in the treatment of several vitamin D deficiency-related skeletal and extraskeletal diseases.

Scientific opinion on the tolerable upper intake level for vitamin D, including the derivation of a conversion factor for calcidiol monohydrate

Following two requests from the European Commission (EC), the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the revision of the tolerable upper intake level (UL) for vitamin D and to propose a conversion factor (CF) for calcidiol monohydrate into vitamin D3 for labelling purposes. Vitamin D refers to ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), and calcidiol monohydrate. Systematic reviews of the literature were conducted to assess the relative bioavailability of calcidiol monohydrate versus vitamin D3 on serum 25(OH)D concentrations, and for priority adverse health effects of excess vitamin D intake, namely persistent hypercalcaemia/hypercalciuria and endpoints related to musculoskeletal health (i.e. falls, bone fractures, bone mass/density and indices thereof). Based on the available evidence, the Panel proposes a CF for calcidiol monohydrates of 2.5 for labelling purposes. Persistent hypercalciuria, which may be an earlier sign of excess vitamin D than persistent hypercalcaemia, is selected as the critical endpoint on which to base the UL for vitamin D. A lowest-observed-adverse-effect-level (LOAEL) of 250 μg/day is identified from two randomised controlled trials in humans, to which an uncertainty factor of 2.5 is applied to account for the absence of a no-observed-adverse-effect-level (NOAEL). A UL of 100 μg vitamin D equivalents (VDE)/day is established for adults (including pregnant and lactating women) and for adolescents aged 11-17 years, as there is no reason to believe that adolescents in the phase of rapid bone formation and growth have a lower tolerance for vitamin D compared to adults. For children aged 1-10 years, a UL of 50 μg VDE/day is established by considering their smaller body size. Based on available intake data, European populations are unlikely to exceed the UL, except for regular users of food supplements containing high doses of vitamin D.

Hormones and Aging: An Endocrine Society Scientific Statement

Multiple changes occur across various endocrine systems as an individual ages. The understanding of the factors that cause age-related changes and how they should be managed clinically is evolving. This statement reviews the current state of research in the growth hormone, adrenal, ovarian, testicular, and thyroid axes, as well as in osteoporosis, vitamin D deficiency, type 2 diabetes, and water metabolism, with a specific focus on older individuals. Each section describes the natural history and observational data in older individuals, available therapies, clinical trial data on efficacy and safety in older individuals, key points, and scientific gaps. The goal of this statement is to inform future research that refines prevention and treatment strategies in age-associated endocrine conditions, with the goal of improving the health of older individuals.

Evaluating the effect of calcifediol supplementation on seizure frequency in people with drug-resistant epilepsy

The well-known neuroprotective role and involvement of vitamin D in the function of the central nervous system has raised the speculation about the possible antiseizure effect of vitamin D supplementation. This issue is crucial when considering people with epilepsy (PWE), who frequently display vitamin D deficiency, but nowadays data are still unconclusive. In our study, we enrolled 25 adult patients affected by drug-resistant epilepsy and hypovitaminosis D to test the effect of Calcifediol on seizure frequency after 6 months of supplementation. Our findings evidenced that Calcifediol administration completely restored 25-hydroxy vitamin D (25-OHD) and intact parathyroid hormone (iPTH) serum values (p < 0.001 for both) without significant changes of median seizure frequency (-6.1%). Anyway, we observed some rate of PWE responders (32%) to Calcifediol supplementation. Further randomized controlled trials with larger subjects 'samples will be needed to verify the possible antiseizure effect of vitamin D.

Safety and efficacy of a feed additive consisting of 25-hydroxycholecalciferol (produced by Pseudonocardia autotrophicaDSM 32858) for all pigs, all poultry for fattening and ornamental birds and other poultry species (Huvepharma NV)

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a feed additive consisting of 25-hydroxycholecalciferol (produced by Pseudonocardia autotrophica DSM 32858) for all pigs, all poultry for fattening and ornamental birds and other poultry species. The production strain P. autotrophica DSM 32858 is not genetically modified however, uncertainties remain on the possible presence of its viable cells in the final product. Due to the lack of adequate safety data and uncertainty on the presence of nano particles, the FEEDAP Panel cannot conclude on the safety of the additive for the target species and the consumer. The additive was shown not to be irritant to skin or eyes and it is not a skin sensitiser. Considering the low dusting potential of the additive, the FEEDAP Panel concluded that the exposure through inhalation is unlikely. However, the FEEDAP Panel considered that uncertainties remain on genotoxicity and on the possible presence of viable cells of P. autotrophica DSM 32858 in the final product which might have an impact on the safety for the users. The use of the feed additive is considered safe for the environment. The Panel concluded that the additive has a potential to be efficacious under the proposed conditions of use.

Involvement of the secosteroid vitamin D in autoimmune rheumatic diseases and COVID-19

Evidence supporting the extra-skeletal role of vitamin D in modulating immune responses is centred on the effects of its final metabolite, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3, also known as calcitriol), which is regarded as a true steroid hormone. 1,25(OH)2D3, the active form of vitamin D, can modulate the innate immune system in response to invading pathogens, downregulate inflammatory responses and support the adaptive arm of the immune system. Serum concentrations of its inactive precursor 25-hydroxyvitamin D3 (25(OH)D3, also known as calcidiol) fluctuate seasonally (being lowest in winter) and correlate negatively with the activation of the immune system as well as with the incidence and severity of autoimmune rheumatic diseases such as rheumatoid arthritis, systemic lupus erythematosus and systemic sclerosis. Thus, a low serum concentration of 25(OH)D3 is considered to be a risk factor for autoimmune rheumatic diseases and vitamin D3 supplementation seems to improve the prognosis; moreover, long-term vitamin D3 supplementation seems to reduce their incidence (i.e. rheumatoid arthritis). In the setting of COVID-19, 1,25(OH)2D3 seems to downregulate the early viral phase (SARS-CoV-2 infection), by enhancing innate antiviral effector mechanisms, as well as the later cytokine-mediated hyperinflammatory phase. This Review provides an update of the latest scientific and clinical evidence concerning vitamin D and immune response in autoimmune rheumatic diseases and COVID-19, which justify the need for monitoring of serum 25(OH)D3 concentrations and for appropriate supplementation following clinical trial-based approaches.

Improving vitamin D content in pork meat by UVB biofortification

Vitamin D deficiency is prevalent worldwide and identification of alternative food-based strategies are urgently warranted. In two studies, 12-week old crossbred pigs (Duroc x (Large White x Landrace)) were exposed daily to narrowband UVB radiation for ∼10 weeks or control (no UVB exposure) until slaughter. In Study 1 (n = 48), pigs were exposed to UVB for 2 min and in Study 2 (n = 20), this duration was tripled to 6 min. All pigs were fed the maximum permitted 2000 IU vitamin D₃/kg feed. Loin meat was cooked prior to vitamin D LC-MS/MS analysis. In Study 1, pork loin vitamin D₃ did not differ between groups. Study 2 provided longer UVB exposure time and resulted in significantly higher loin vitamin D₃ (11.97 vs. 6.03 μg/kg), 25(OH)D₃ (2.09 vs. 1.65 μg/kg) and total vitamin D activity (22.88 vs. 14.50 μg/kg) concentrations, compared to control (P < 0.05). Pigs remained healthy during both studies and developed no signs of erythema. Biofortification by UVB radiation provides an effective strategy to further safely increase the naturally occurring vitamin D content of pork loin, alongside feed supplementation.

Calcifediol: Why, When, How Much?

Vitamin D deficiency is a constantly growing health problem worldwide. Adults affected with hypovitaminosis D could experience negative consequences on their musculoskeletal system and extra-skeletal health. In fact, an optimal vitamin D status is essential to ensure the correct bone, calcium, and phosphate homeostasis. To improve vitamin D status, it is important to not only increase the intake of food fortified with vitamin D, but also to administer vitamin D supplementation when required. Vitamin D3 (cholecalciferol) is the most widely used supplement. In recent years, the administration of calcifediol (25(OH)D3), the direct precursor of the biologically active form of vitamin D3, as oral vitamin D supplementation has progressively grown. Here, we report the potential medical benefits of some peculiar biological actions of calcifediol, discussing the possible specific clinical scenarios in which the oral intake of calcifediol could be most effective to restore the correct serum levels of 25(OH)D3. In summary, the aim of this review is to provide insights into calcifediol-related rapid non-genomic responses and the possible use of this vitamin D metabolite as a supplement for the treatment of people with a higher risk of hypovitaminosis D.

Comparison of calcifediol with vitamin D for prevention or cure of vitamin D deficiency

Vitamin D deficiency remains prevalent, with about 7% of the world's population living with severe vitamin D deficiency and about one third with mild deficiency. We compare the relative merits of calcifediol or 25-hydroxyvitamin D (25OHD) compared to vitamin D itself for supplementation as to prevent or cure vitamin D deficiency. The intestinal absorption of calcifediol is nearly 100% and thus higher than that of vitamin D itself. Moreover, calcifediol is absorbed by the intestinal cells and transported through the portal vein and thus immediately accessible to the circulation, while vitamin D is transported with chylomicrons through the lymph system. Therefore, in case of fat malabsorption or after bariatric surgery, calcifediol is much better absorbed in comparison with vitamin D itself. Serum 25OHD increases linearly with increasing doses of calcifediol, whereas serum 25OHD reaches a plateau when higher oral doses of vitamin D are used. Calcifediol, on a weight basis, is about 3 times more potent than vitamin D in subjects with mild vitamin D deficiency. This potency is even 6-8 times higher than vitamin D when baseline serum 25OHD is higher or when large doses are compared. In conclusion, calcifediol is an alternative option to correct vitamin D deficiency and may even be the preferred strategy in case of intestinal fat malabsorption, after bariatric surgery or in case of other conditions with suspected impaired 25-hydroxylase activity in the liver.

Calcifediol: a review of its pharmacological characteristics and clinical use in correcting vitamin D deficiency

BACKGROUND

In addition to the role of vitamin D in bone mineralization, calcium and phosphate homeostasis, and skeletal health, evidence suggests an association between vitamin D deficiency and a wide range of chronic conditions. This is of clinical concern given the substantial global prevalence of vitamin D deficiency. Vitamin D deficiency has traditionally been treated with vitamin D₃ (cholecalciferol) or vitamin D₂ (ergocalciferol). Calcifediol (25-hydroxyvitamin D₃) has recently become available more widely.

METHODS

By means of targeted literature searches of PubMed, this narrative review overviews the physiological functions and metabolic pathways of vitamin D, examines the differences between calcifediol and vitamin D₃, and highlights clinical trials conducted with calcifediol in patients with bone disease or other conditions.

RESULTS

For supplemental use in the healthy population, calcifediol can be used at doses of up to 10 µg per day for children ≥ 11 years and adults and up to 5 µg/day in children 3-10 years. For therapeutic use of calcifediol under medical supervision, the dose, frequency and duration of treatment is determined according to serum 25(OH)D concentrations, condition, type of patient and comorbidities. Calcifediol differs pharmacokinetically from vitamin D₃ in several ways. It is independent of hepatic 25-hydroxylation and thus is one step closer in the metabolic pathway to active vitamin D. At comparable doses to vitamin D₃, calcifediol achieves target serum 25(OH)D concentrations more rapidly and in contrast to vitamin D₃, it has a predictable and linear dose-response curve irrespective of baseline serum 25(OH)D concentrations. The intestinal absorption of calcifediol is relatively preserved in patients with fat malabsorption and it is more hydrophilic than vitamin D₃ and thus is less prone to sequestration in adipose tissue.

CONCLUSION

Calcifediol is suitable for use in all patients with vitamin D deficiency and may be preferable to vitamin D₃ for patients with obesity, liver disease, malabsorption and those who require a rapid increase in 25(OH)D concentrations.

Bioavailability of vitamin D biofortified pork meat: results of an acute human crossover study in healthy adults

Vitamin D intakes are concerningly low. Food-based strategies are urgently warranted to increase vitamin D intakes and subsequently improve 25-hydroxyvitamin D (25(OH)D) concentrations. This acute randomised three-way crossover study investigated the efficacy of vitamin D biofortified pork derived from pigs exposed to UVB light to increase serum 25(OH)D₃ concentrations, compared to a dose-matched vitamin D₃ supplement and control pork in adults (n = 14). Blood samples were obtained at baseline and then 1.5, 3, 6, 9 and 24 h postprandially. There was a significant effect of time (p < 0.01) and a significant treatment*time interaction (p < 0.05). UV pork and supplement significantly increased within-group serum 25(OH)D₃ concentrations over timepoints (p < 0.05) (max. change 0.9 nmol/L (2.2%) UV pork, 1.5 nmol/L (3.5%) supplement, 0.7 nmol/L (1.9%) control). Vitamin D biofortified pork modestly increased 25(OH)D₃ concentrations and produced a similar response pattern as a dose-matched vitamin D supplement, but biofortification protocols should be further optimised to ensure differentiation from standard pork.

Effects of maternal and offspring treatment with two dietary sources of vitamin D on the mineral homeostasis, bone metabolism and locomotion of offspring fed protein- and phosphorus-reduced diets

The present study aims to compare the effects of maternal and offspring treatment with 25-hydroxycholecalciferol (25-OHD₃) and vitamin D₃ on vitamin D status, mineral homoeostasis, bone metabolism and locomotion in the offspring. Either vitamin D₃ (50 μg/kg diet) or 25-OHD₃ (50 μg/kg diet) was supplemented to the gestation and lactation diets of 49 multiparous sows and/or to the diets of their growing offspring. Treatment of the sows did not affect plasma concentrations of 25-OHD₃ of the offspring. Pigs fed 25-OHD₃ had higher plasma concentrations of 25-OHD₃ than pigs that received vitamin D₃ during rearing and fattening. However, neither plasma concentrations of calcium, phosphate and bone markers during the observation period nor bone ash and bone mineral density at slaughter were clearly affected by the treatment. Maternal and offspring treatment with 25-OHD₃ instead of vitamin D₃ resulted in a slight reduction in the prevalence of leg swelling. In addition, more pigs walked with even steps and normal stride length. Further studies are needed to test whether the slight effects observed in the present experiment are reproducible and of relevance for animal health and welfare. In that case, the underlying mechanisms should be revealed in order to take advantage of potentially beneficial influences especially under certain feeding regimes.

Guidelines for Preventing and Treating Vitamin D Deficiency: A 2023 Update in Poland

Introduction: All epidemiological studies suggest that vitamin D deficiency is prevalent among the Polish general population. Since vitamin D deficiency was shown to be among the risk factors for many diseases and for all-cause mortality, concern about this problem led us to update the previous Polish recommendations. Methods: After reviewing the epidemiological evidence, case-control studies and randomized control trials (RCTs), a Polish multidisciplinary group formulated questions on the recommendations for prophylaxis and treatment of vitamin D deficiency both for the general population and for the risk groups of patients. The scientific evidence of pleiotropic effects of vitamin D as well as the results of panelists' voting were reviewed and discussed. Thirty-four authors representing different areas of expertise prepared position statements. The consensus group, representing eight Polish/international medical societies and eight national specialist consultants, prepared the final Polish recommendations. Results: Based on networking discussions, the ranges of total serum 25-hydroxyvitamin D concentration indicating vitamin D deficiency [<20 ng/mL (<50 nmol/L)], suboptimal status [20-30 ng/mL (50-75 nmol/L)], and optimal concentration [30-50 ng/mL (75-125 nmol/L)] were confirmed. Practical guidelines for cholecalciferol (vitamin D3) as the first choice for prophylaxis and treatment of vitamin D deficiency were developed. Calcifediol dosing as the second choice for preventing and treating vitamin D deficiency was introduced. Conclusions: Improving the vitamin D status of the general population and treatment of risk groups of patients must be again announced as healthcare policy to reduce a risk of spectrum of diseases. This paper offers consensus statements on prophylaxis and treatment strategies for vitamin D deficiency in Poland.