Calcifediol is superior to cholecalciferol in improving vitamin D status in postmenopausal women: a randomized trial

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.

Analysis of the Efficacy and Safety of Weekly Calcifediol 100 µg in Vitamin D Deficient Patients

Background/Objectives: Adequate vitamin D levels are critical for overall health, yet vitamin D deficiency remains prevalent. This study aims to evaluate the efficacy and safety of a standardized weekly supplementation regimen of 100 μg calcifediol for patients with varying degrees of vitamin D deficiency. Methods: A post hoc pool analysis was conducted from a randomized, double-blind, placebo-controlled, multicenter, two-cohort trial. Cohort 1 included vitamin D mild deficiency patients (25(OH)D levels > 10 < 20 ng/mL) and Cohort 2 severe deficiency patients (25(OH)D levels ≤ 10 ng/mL). As both had placebo and weekly calcifediol 100 μg arms (ratio 1:2), a pooled analysis of safety and efficacy was conducted. The primary outcome was the percentage of subjects achieving 25(OH)D levels ≥ 20 ng/mL and/or ≥30 ng/mL at various time points. Results: A total of 401 participants across both cohorts were included in the analysis, 130 who received a placebo and 271 calcifediol 100 µg weekly. By week 52, 94.5% of individuals in the calcifediol group achieved 25(OH)D levels ≥ 20 ng/mL, compared to 25.3% in the placebo group (p < 0.0001). At this same week, 80.5% of subjects in the calcifediol group, but none in the placebo group (p < 0.0001), had 25(OH)D levels ≥ 30 ng/mL. The mean 25(OH)D level plateaued around 40.7 ng/mL from weeks 16 to 52. The frequency of treatment-emergent adverse events was similar in both groups, placebo and calcifediol. Conclusions: Weekly supplementation of 100 μg calcifediol effectively restores vitamin D levels in individuals with both mild and severe deficiencies, demonstrating a favourable safety profile.

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.

The role of nutritional vitamin D in chronic kidney disease-mineral and bone disorder in children and adults with chronic kidney disease, on dialysis, and after kidney transplantation-a European consensus statement

Vitamin D deficiency is common in patients with chronic kidney disease (CKD) and associates with poor outcomes. Current clinical practice guidelines recommend supplementation with nutritional vitamin D as for the general population. However, recent large-scale clinical trials in the general population failed to demonstrate a benefit of vitamin D supplementation on skeletal or non-skeletal outcomes, fueling a debate on the rationale for screening for and correcting vitamin D deficiency, both in non-CKD and CKD populations. In a collaboration between the European Renal Osteodystrophy initiative of the European Renal Association (ERA) and the European Society for Paediatric Nephrology (ESPN), an expert panel performed an extensive literature review and formulated clinical practice points on vitamin D supplementation in children and adults with CKD and after kidney transplantation. These were reviewed by a Delphi panel of members from relevant working groups of the ERA and ESPN. Key clinical practice points include recommendations to monitor for, and correct, vitamin D deficiency in children and adults with CKD and after kidney transplantation, targeting 25-hydroxyvitamin D levels >75 nmol/l (>30 ng/ml). Although vitamin D supplementation appears well-tolerated and safe, it is recommended to avoid mega-doses (≥100 000 IU) and very high levels of 25 hydroxyvitamin D (>150-200 nmol/l, or 60-80 ng/ml) to reduce the risk of toxicity. Future clinical trials should investigate the benefit of vitamin D supplementation on patient-relevant outcomes in the setting of vitamin D deficiency across different stages of CKD.

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 Deficiency Meets Hill's Criteria for Causation in SARS-CoV-2 Susceptibility, Complications, and Mortality: A Systematic Review

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.

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.

Selective Oxidation of Vitamin D3 Enhanced by Long-Range Effects of a Substrate Channel Mutation in Cytochrome P450BM3 (CYP102A1)

Vitamin D deficiency affects nearly half the population, with many requiring or opting for supplements with vitamin D3 (VD3), the precursor of vitamin D (1α,25-dihydroxyVD3). 25-HydroxyVD3, the circulating form of vitamin D, is a more effective supplement than VD3 but its synthesis is complex. We report here the engineering of cytochrome P450BM3 (CYP102A1) for the selective oxidation of VD3 to 25-hydroxyVD3. Long-range effects of the substrate-channel mutation Glu435Ile promoted binding of the VD3 side chain close to the heme, enhancing VD3 oxidation activity that reached 6.62 g of 25-hydroxyVD3 isolated from a 1-litre scale reaction (69.1 % yield; space-time-yield 331 mg/L/h).

Native vitamin D in CKD and renal transplantation: meaning and rationale for its supplementation

Chronic kidney disease (CKD) poses a significant epidemiological challenge, necessitating effective patient management strategies. Nutritional intervention, particularly vitamin D supplementation, has garnered attention for its potential therapeutic utility in CKD. Despite widespread acknowledgment of the importance of vitamin D, particularly in bone and mineral metabolism, its supplementation in CKD patients for non-skeletal purposes remains contentious due to limited evidence. Hypovitaminosis D linked with CKD substantially contributes to disturbances in mineral and bone metabolism, increasing the risks of cardiovascular complications and skeletal disorders. Notably, CKD patients experience progressive vitamin D deficiency, exacerbating as the disease progresses. Guidelines recommend monitoring 25-hydroxyvitamin D (25 (OH)-D) levels due to their correlation with mineral metabolism parameters, although robust evidence for recommending supplementation is lacking. The primary aim of this paper is to focus on the main open questions regarding vitamin D supplementation in CKD, reporting the current evidence concerning the role of vitamin D supplementation in CKD and in renal transplant recipients.

Calcifediol boosts efficacy of ChAdOx1 nCoV-19 vaccine by upregulating genes promoting memory T cell responses

The ChAdOx1 nCoV-19 (COVISHIELD) vaccine has emerged as a pivotal tool in the global fight against the COVID-19 pandemic. In our previous study eligible subjects were supplemented with calcifediol, a direct precursor to the biologically active form of vitamin D, calcitriol with an objective to enhance the immunogenicity of the COVISHIELD vaccine. Herein we investigated the effects of calcifediol supplementation on gene expression profiles in individuals who received the COVISHIELD vaccine. Peripheral blood mononuclear cells were isolated from vaccinated individuals with and without calcifediol supplementation at baseline, 3rd and 6th month, and the gene expression profiles were analyzed using high-throughput sequencing. The results revealed distinct patterns of gene expression associated with calcifediol supplementation, suggesting potential molecular mechanisms underlying the beneficial effects of calcifediol in improving the efficacy of COVISHIELD vaccine via augmentation of T cell activation, proliferation and T cell memory responses. Additionally, there was upregulation of NOD like receptor, JAK/STAT and TGF beta signaling pathways. Calcifediol supplementation in vaccinated individuals also downregulated the pathways related to the Coronavirus disease. Taken together, our findings provide valuable insights into the interplay between vitamin D receptor (VDR) signaling and vaccine-induced immune responses and offer another approach in improving vaccination induced antiviral responses.

Clinical Practice Guidelines of the Latin American Federation of Endocrinology for the use of vitamin D in the maintenance of bone health: recommendations for the Latin American context

INTRODUCTION

These guidelines aim to provide evidence-based recommendations for the supplementation of Vitamin D in maintaining bone health. An unmet need persists in Latin American regarding the availability of clinical and real-world data for rationalizing the use of vitamin D supplementation. The objective of these guidelines is to establish clear and practical recommendations for healthcare practitioners from Latin American countries to address Vitamin D insufficiency in clinical practice.

METHODS

The guidelines were developed according to the GRADE-ADOLOPMENT methodology for the adaptation or adoption of CPGs or evidence-based recommendations. A search for high quality CPGs was complemented through a comprehensive review of recent literature, including randomized controlled trials, observational studies, and systematic reviews evaluating the effects of Vitamin D supplementation on bone health. The evidence to decision framework proposed by the GRADE Working Group was implemented by a panel of experts in endocrinology, bone health, and clinical research.

RESULTS

The guidelines recommend Vitamin D supplementation for individuals aged 18 and above, considering various populations, including healthy adults, individuals with osteopenia, osteoporosis patients, and institutionalized older adults. These recommendations offer dosing regimens depending on an individualized treatment plan, and monitoring intervals of serum 25-hydroxyvitamin D levels and adjustments based on individual results.

DISCUSSION

The guidelines highlight the role of Vitamin D in bone health and propose a standardized approach for healthcare practitioners to address Vitamin D insufficiency across Latin America. The panel underscored the necessity for generating local data and stressed the importance of considering regional geography, social dynamics, and cultural specificities when implementing these guidelines.

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.

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.

Changes in miRNA expression in the lungs of pigs supplemented with different levels and forms of vitamin D

BACKGROUND

Vitamin D is an immunomodulator, and its effects have been linked to many diseases, including the pathogenesis of cancer. However, the effect of vitamin D supplementation on the regulation of gene expression of the lungs is not fully understood. This study aims to determine the effect of the increased dose of cholecalciferol and a combination of cholecalciferol + calcidiol, as well as the replacement of cholecalciferol with calcidiol, on the miRNA profile of healthy swine lungs.

METHODS AND RESULTS

The swine were long-term (88 days) supplemented with a standard dose (2000IU/kg) of cholecalciferol and calcidiol, the increased dose (3000 IU/kg) of cholecalciferol, and the cholecalciferol + calcidiol combination: grower: 3000 IU/Kg of vitamin D (67% of cholecalciferol and 33% of calcidiol), finisher 2500 IU/Kg of vitamin D (60% of cholecalciferol and 40% of calcidiol). Swine lung tissue was used for Next Generation Sequencing (NGS) of miRNA. Long-term supplementation with the cholecalciferol + calcidiol combination caused significant changes in the miRNA profile. They embraced altered levels of the expression of miR-150, miR-193, miR-145, miR-574, miR-340, miR-381, miR-148 and miR-96 (q-value < 0.05). In contrast, raising the dose of cholecalciferol only changed the expression of miR-215, and the total replacement of cholecalciferol with calcidiol did not significantly affect the miRNAome profile.

CONCLUSIONS

The functional analysis of differentially expressed miRNAs suggests that the use of the increased dose of the cholecalciferol + calcidiol combination may affect tumorigenesis processes through, inter alia, modulation of gene regulation of the TGF- β pathway and pathways related to metabolism and synthesis of glycan.

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.

Infections and Autoimmunity-The Immune System and Vitamin D: A Systematic Review

Both 25-autoimmunity and(25(OH)D: calcifediol) and its active form, 1,25-dihydroxyvitamin D (1,25(OH)2D: calcitriol), play critical roles in protecting humans from invasive pathogens, reducing risks of autoimmunity, and maintaining health. Conversely, low 25(OH)D status increases susceptibility to infections and developing autoimmunity. This systematic review examines vitamin D's mechanisms and effects on enhancing innate and acquired immunity against microbes and preventing autoimmunity. The study evaluated the quality of evidence regarding biology, physiology, and aspects of human health on vitamin D related to infections and autoimmunity in peer-reviewed journal articles published in English. The search and analyses followed PRISMA guidelines. Data strongly suggested that maintaining serum 25(OH)D concentrations of more than 50 ng/mL is associated with significant risk reduction from viral and bacterial infections, sepsis, and autoimmunity. Most adequately powered, well-designed, randomized controlled trials with sufficient duration supported substantial benefits of vitamin D. Virtually all studies that failed to conclude benefits or were ambiguous had major study design errors. Treatment of vitamin D deficiency costs less than 0.01% of the cost of investigation of worsening comorbidities associated with hypovitaminosis D. Despite cost-benefits, the prevalence of vitamin D deficiency remains high worldwide. This was clear among those who died from COVID-19 in 2020/21-most had severe vitamin D deficiency. Yet, the lack of direction from health agencies and insurance companies on using vitamin D as an adjunct therapy is astonishing. Data confirmed that keeping an individual's serum 25(OH)D concentrations above 50 ng/mL (125 nmol/L) (and above 40 ng/mL in the population) reduces risks from community outbreaks, sepsis, and autoimmune disorders. Maintaining such concentrations in 97.5% of people is achievable through daily safe sun exposure (except in countries far from the equator during winter) or taking between 5000 and 8000 IU vitamin D supplements daily (average dose, for non-obese adults, ~70 to 90 IU/kg body weight). Those with gastrointestinal malabsorption, obesity, or on medications that increase the catabolism of vitamin D and a few other specific disorders require much higher intake. This systematic review evaluates non-classical actions of vitamin D, with particular emphasis on infection and autoimmunity related to the immune system.

Therapeutic Effects of Vitamin D on Vaginal, Sexual, and Urological Functions in Postmenopausal Women

Recent years have witnessed the emergence of growing evidence concerning vitamin D's potential role in women's health, specifically in postmenopausal women. This evidence also includes its connection to various genitourinary disorders and symptoms. Numerous clinical studies have observed improvements in vulvovaginal symptoms linked to the genitourinary syndrome of menopause (GSM) with vitamin D supplementation. These studies have reported positive effects on various aspects, such as vaginal pH, dryness, sexual functioning, reduced libido, and decreased urinary tract infections. Many mechanisms underlying these pharmacological effects have since been proposed. Vitamin D receptors (VDRs) have been identified as a major contributor to its effects. It is now well known that VDRs are expressed in the superficial layers of the urogenital organs. Additionally, vitamin D plays a crucial role in supporting immune function and modulating the body's defense mechanisms. However, the characterization of these effects requires more investigation. Reviewing existing evidence regarding vitamin D's impact on postmenopausal women's vaginal, sexual, and urological health is the purpose of this article. As research in this area continues, there is a potential for vitamin D to support women's urogenital and sexual health during the menopausal transition and postmenopausal periods.

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.

Prevention of COVID-19 with oral vitamin D supplemental therapy in essential healthcare teams (PROTECT): protocol for a multicentre, triple-blind, randomised, placebo-controlled trial

INTRODUCTION

In the COVID-19 pandemic, healthcare workers (HCWs) were at high risk of infection due to their exposure to COVID infections. HCWs were the backbone of our healthcare response to this pandemic; every HCW withdrawn or lost due to infection had a substantial impact on our capacity to deliver care. Primary prevention was a key approach to reduce infection. Vitamin D insufficiency is highly prevalent in Canadians and worldwide. Vitamin D supplementation has been shown to significantly decrease the risk of respiratory infections. Whether this risk reduction would apply to COVID-19 infections remained to be determined. This study aimed to determine the impact of high-dose vitamin D supplementation on incidence of laboratory-confirmed COVID-19 infection rate and severity in HCWs working in high COVID incidence areas.

METHODS AND ANALYSIS

PROTECT was a triple-blind, placebo-controlled, parallel-group multicentre trial of vitamin D supplementation in HCWs. Participants were randomly allocated in a 1:1 ratio in variable block size to intervention (one oral loading dose of 100 000 IU vitamin D₃+10 000 IU weekly vitamin D₃) or control (identical placebo loading dose+weekly placebo). The primary outcome was the incidence of laboratory-confirmed COVID-19 infection, documented by RT-qPCR on salivary (or nasopharyngeal) specimens obtained for screening or diagnostic purposes, as well as self-obtained salivary specimens and COVID-19 seroconversion at endpoint. Secondary outcomes included disease severity; duration of COVID-19-related symptoms; COVID-19 seroconversion documented at endpoint; duration of work absenteeism; duration of unemployment support; and adverse health events. The trial was terminated prematurely, due to recruitment difficulty.

ETHICS AND DISSEMINATION

This study involves human participants and was approved by the Research Ethics Board (REB) of the Centre hospitalier universitaire (CHU) Sainte-Justine serving as central committee for participating institutions (#MP-21-2021-3044). Participants provided written informed consent to participate in the study before taking part. Results are being disseminated to the medical community via national/international conferences and publications in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

https://clinicaltrials.gov/ct2/show/NCT04483635.

Calcifediol Cornerstone of the Vitamin D Endocrine System

It is likely that rickets has afflicted humanity since the dawn of time, but it was first described in great detail in the mid-17th century [...].

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.

Determinants and Effects of Vitamin D Supplementation in Postmenopausal Women: A Systematic Review

Hormonal fluctuations, excessive clothing covering, sunscreen use, changes in body fat composition, a vitamin D-deficient diet, and a sedentary lifestyle can all predispose postmenopausal women to vitamin D deficiency. An effective supplementation plan requires a thorough understanding of underlying factors to achieve the desired therapeutic concentrations. The objective of this study was to conduct a systematic review of the predictors that affect vitamin D status in postmenopausal women. From inception to October 2022, we searched MEDLINE, Embase, Web of Science, Scopus, and clinical trial registries. Randomized clinical trials of postmenopausal women taking supplements of vitamin D with serum 25-hydroxyvitamin D (25(OH)D) measurement as the trial outcome were included. Two independent reviewers screened selected studies for full-text review. The final assessment covered 19 trials within 13 nations with participants aged 51 to 78. Vitamin D supplementation from dietary and pharmaceutical sources significantly increased serum 25(OH)D to optimal levels. Lower baseline serum 25(OH)D, lighter skin color, longer treatment duration, and prolonged skin exposure were all associated with a better response to vitamin D supplementation in postmenopausal women.

Long-Term Treatment and Effect of Discontinuation of Calcifediol in Postmenopausal Women with Vitamin D Deficiency: A Randomized Trial

Vitamin D plays a major role in bone health and probably also in multiple extraskeletal acute and chronic diseases. Although supplementation with calcifediol, a vitamin D metabolite, has demonstrated efficacy and safety in short-term clinical trials, its effects after long-term monthly administration have been studied less extensively. This report describes the results of a 1-year, phase III-IV, double-blind, randomized, controlled, parallel, multicenter superiority clinical trial to assess the efficacy and safety of monthly calcifediol 0.266 mg versus cholecalciferol 25,000 IU (0.625 mg) in postmenopausal women with vitamin D deficiency (25(OH)D < 20 ng/mL). A total of 303 women were randomized and 298 evaluated. Patients were randomized 1:1:1 to calcifediol 0.266 mg/month for 12 months (Group A1), calcifediol 0.266 mg/month for 4 months followed by placebo for 8 months (Group A2), and cholecalciferol 25,000 IU/month (0.625 mg/month) for 12 months (Group B). By month 4, stable 25(OH)D levels were documented with both calcifediol and cholecalciferol (intention-to-treat population): 26.8 ± 8.5 ng/mL (Group A1) and 23.1 ± 5.4 ng/mL (Group B). By month 12, 25(OH)D levels were 23.9 ± 8.0 ng/mL (Group A1) and 22.4 ± 5.5 ng/mL (Group B). When calcifediol treatment was withdrawn in Group A2, 25(OH)D levels decreased to baseline levels (28.5 ± 8.7 ng/mL at month 4 versus 14.4 ± 6.0 ng/mL at month 12). No relevant treatment-related safety issues were reported in any of the groups. The results confirm that long-term treatment with monthly calcifediol in vitamin D-deficient patients is effective and safe. The withdrawal of treatment leads to a pronounced decrease of 25(OH)D levels. Calcifediol presented a faster onset of action compared to monthly cholecalciferol. Long-term treatment produces stable and sustained 25(OH)D concentrations with no associated safety concerns. © 2023 Faes Farma SA. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Effect of vitamin D3 vs. calcifediol on VDR concentration and fiber size in skeletal muscle

INTRODUCTION

This study sought to examine the effect of vitamin D₃ (VD₃) 3200 IU/d, calcifediol (HyD) 20mcg/d, or placebo on intramyonuclear vitamin D receptor (VDR) concentration, muscle fiber cross-sectional area (FCSA), and muscle satellite cell activation.

MATERIALS AND METHODS

It was conducted on a subset of the VD₃ (n = 12), HyD (n = 11), and placebo (n = 13) groups who participated in the 6-month randomized controlled HyD Osteopenia Study in postmenopausal women. Baseline and 6-month vastus lateralis muscle cross sections were probed for VDR, fiber type I and II, and PAX7 (satellite cell marker) using immunofluorescence.

RESULTS

Baseline mean ± SD age was 61 ± 4 years and serum 25-hydroxyvitamin D (25OHD) level was 55.1 ± 22.8 nmol/L. Baseline characteristics did not differ significantly by group. Six-month mean ± SD 25OHD levels were 138.7 ± 22.2 nmol/L (VD₃), 206.8 ± 68.8 nmol/L (HyD), and 82.7 ± 36.1 nmol/L (placebo), ANOVA P < 0.001. There were no significant group differences in 6-month change in VDR concentration (ANOVA P = 0.227). Mean ± SD percent 6-month changes in type I FCSA were 20.5 ± 32.7% (VD₃), - 6.6 ± 20.4% (HyD), and - 0.3 ± 14.0% (placebo, ANOVA P = 0.022). Type II FCSA or PAX7 concentration did not change significantly by group (all P > 0.358).

CONCLUSION

This study demonstrated no significant change in intramyonuclear VDR in response to either form of vitamin D vs. placebo. Type I FCSA significantly increased with VD₃, but not with HyD at 6 months. As type I fibers are more fatigue resistant than type II, enlargement in type I suggests potential for improved muscle endurance. Although HyD resulted in the highest 25OHD levels, no skeletal muscle benefits were noted at these high levels.

CLINICAL TRIAL

NCT02527668.

Role of vitamin D supplementation in the management of musculoskeletal diseases: update from an European Society of Clinical and Economical Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) working group

Vitamin D is a key component for optimal growth and for calcium-phosphate homeostasis. Skin photosynthesis is the main source of vitamin D. Limited sun exposure and insufficient dietary vitamin D supply justify vitamin D supplementation in certain age groups. In older adults, recommended doses for vitamin D supplementation vary between 200 and 2000 IU/day, to achieve a goal of circulating 25-hydroxyvitamin D (calcifediol) of at least 50 nmol/L. The target level depends on the population being supplemented, the assessed system, and the outcome. Several recent large randomized trials with oral vitamin D regimens varying between 2000 and 100,000 IU/month and mostly conducted in vitamin D-replete and healthy individuals have failed to detect any efficacy of these approaches for the prevention of fracture and falls. Considering the well-recognized major musculoskeletal disorders associated with severe vitamin D deficiency and taking into account a possible biphasic effects of vitamin D on fracture and fall risks, an European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) working group convened, carefully reviewed, and analyzed the meta-analyses of randomized controlled trials on the effects of vitamin D on fracture risk, falls or osteoarthritis, and came to the conclusion that 1000 IU daily should be recommended in patients at increased risk of vitamin D deficiency. The group also addressed the identification of patients possibly benefitting from a vitamin D loading dose to achieve early 25-hydroxyvitamin D therapeutic level or from calcifediol administration.

Vitamin D Endocrine System and COVID-19: Treatment with Calcifediol

The COVID-19 pandemic is the greatest challenge facing modern medicine and public health systems. The viral evolution of SARS-CoV-2, with the emergence of new variants with in-creased infectious potential, is a cause for concern. In addition, vaccination coverage remains in-sufficient worldwide. Therefore, there is a need to develop new therapeutic options, and/or to optimize the repositioning of drugs approved for other indications for COVID-19. This may include the use of calcifediol, the prohormone of the vitamin D endocrine system (VDES) as it may have potential useful effects for the treatment of COVID-19. We review the aspects associating COVID-19 with VDES and the potential use of calcifediol in COVID-19. VDES/VDR stimulation may enhance innate antiviral effector mechanisms, facilitating the induction of antimicrobial peptides/autophagy, with a critical modulatory role in the subsequent host reactive hyperinflammatory phase during COVID-19: By decreasing the cytokine/chemokine storm, regulating the renin–angiotensin–bradykinin system (RAAS), modulating neutrophil activity and maintaining the integrity of the pulmonary epithelial barrier, stimulating epithelial repair, and directly and indirectly decreasing the increased coagulability and prothrombotic tendency associated with severe COVID-19 and its complications. Available evidence suggests that VDES/VDR stimulation, while maintaining optimal serum 25OHD status, in patients with SARS-CoV-2 infection may significantly reduce the risk of acute respiratory distress syndrome (ARDS) and severe COVID-19, with possible beneficial effects on the need for mechanical ventilation and/or intensive care unit (ICU) admission, as well as deaths in the course of the disease. The pharmacokinetic and functional characteristics of calcifediol give it superiority in rapidly optimizing 25OHD levels in COVID-19. A pilot study and several observational intervention studies using high doses of calcifediol (0.532 mg on day 1 and 0.266 mg on days 3, 7, 14, 21, and 28) dramatically decreased the need for ICU admission and the mortality rate. We, therefore, propose to use calcifediol at the doses described for the rapid correction of 25OHD deficiency in all patients in the early stages of COVID-19, in association, if necessary, with the new oral antiviral agents.

Calcifediol for Use in Treatment of Respiratory Disease

Calcifediol is the prohormone of the vitamin D endocrine system (VDES). It requires hydroxylation to move to 1,25(OH)2D3 or calcitriol, the active form that exerts its functions by activating the vitamin D receptor (VDR) that is expressed in many organs, including the lungs. Due to its rapid oral absorption and because it does not require first hepatic hydroxylation, it is a good option to replace the prevalent deficiency of vitamin D (25 hydroxyvitamin D; 25OHD), to which patients with respiratory pathologies are no strangers. Correcting 25OHD deficiency can decrease the risk of upper respiratory infections and thus improve asthma and COPD control. The same happens with other respiratory pathologies and, in particular, COVID-19. Calcifediol may be a good option for raising 25OHD serum levels quickly because the profile of inflammatory cytokines exhibited by patients with inflammatory respiratory diseases, such as asthma, COPD or COVID-19, can increase the degradation of the active metabolites of the VDES. The aim of this narrative revision is to report the current evidence on the role of calcifediol in main respiratory diseases. In conclusion, good 25OHD status may have beneficial effects on the clinical course of respiratory diseases, including COVID-19. This hypothesis should be confirmed in large, randomized trials. Otherwise, a rapid correction of 25(OH)D deficiency can be useful for patients with respiratory disease.

Treatment of Vitamin D Deficiency with Calcifediol: Efficacy and Safety Profile and Predictability of Efficacy

Calcifediol (25-OH-vitamin D3) is the prohormone of the vitamin D endocrine system. It is used to prevent and treat vitamin D deficiency. Calcifediol, as well as cholecalciferol (vitamin D3), is efficient and safe in the general population, although calcifediol has certain advantages over cholecalciferol, such as its rapid onset of action and greater potency. This review analyzed studies comparing the efficacy and safety of both calcifediol and cholecalciferol drugs in the short and long term (>6 months). Calcifediol was found to be more efficacious, with no increase in toxicity. We also assessed the predictability of both molecules. A 25OHD increase depends on the dose and frequency of calcifediol administration. In contrast, after cholecalciferol administration, 25OHD increase depends on more factors than dose and frequency of administration, also phenotypic aspects (such as obesity and malabsorption), and genotypic factors impacts in this increase.

Effect of Calcifediol on Physical Performance and Muscle Strength Parameters: A Systematic Review and Meta-Analysis

There is general agreement that optimal vitamin D status is necessary for bones, muscles, and general health, particularly in older adults, who are at higher risk of negative consequences of vitamin D deficiency, including sarcopenia; vitamin D supplementation is proposed as a potential intervention to mitigate sarcopenia. Several RCTs have reported that calcifediol (25(OH)D) was more potent than cholecalciferol in increasing plasma 25(OH)D. The present systematic review and meta-analysis aimed to summarize the effects of calcifediol on physical performance and muscle strength. We searched databases from inception to 1 January 2022 for studies investigating calcifediol on physical performance or muscle strength parameters. We calculated the difference between the means of follow-up vs. baseline data using standardized mean differences (SMD) and their 95% confidence intervals (CIs); a random-effect model was considered for all of the analyses. Seven RCTs were included in the meta-analysis. Calcifediol significantly improved gait speed (SMD = 2.500; 95%CI = 1.768−3.223; p < 0.0001); handgrip strength (n = 5446 participants, SMD = 0.532; 95%CI: 0.305−0.758; p < 0.0001; I2 = 20.2%); and leg extension (n = 4318 participants, SMD = 0.641; 95%CI: 0.346 to 0.935; p < 0.0001; I2 = 18.8%;) vs. baseline values. In conclusion, in this systematic review and meta-analysis, we observed that calcifediol may have a positive effect on muscle strength parameters, with less evidence on physical performance. These data further indicate the importance of vitamin D and, in particular, of calcifediol, not only on bone metabolism but also on muscle parameters and sarcopenia.

Skin, hair and beyond: the impact of menopause

The skin is an endocrine organ and a major target of hormones such as estrogens, androgens and cortisol. Besides vasomotor symptoms (VMS), skin and hair symptoms often receive less attention than other menopausal symptoms despite having a significant negative effect on quality of life. Skin and mucosal menopausal symptoms include dryness and pruritus, thinning and atrophy, wrinkles and sagging, poor wound healing and reduced vascularity, whereas skin premalignant and malignant lesions and skin aging signs are almost exclusively caused by environmental factors, especially solar radiation. Hair menopausal symptoms include reduced hair growth and density on the scalp (diffuse effluvium due to follicular rarefication and/or androgenetic alopecia of female pattern), altered hair quality and structure, and increased unwanted hair growth on facial areas. Hormone replacement therapy (HRT) is not indicated for skin and hair symptoms alone due to the risk-benefit balance, but wider potential benefits of HRT (beyond estrogen's effect on VMS, bone, breast, heart and blood vessels) to include skin, hair and mucosal benefits should be discussed with women so that they will be able to make the best possible informed decisions on how to prevent or manage their menopausal symptoms.

Clinical Practice in the Prevention, Diagnosis and Treatment of Vitamin D Deficiency: A Central and Eastern European Expert Consensus Statement

Vitamin D deficiency has a high worldwide prevalence, but actions to improve this public health problem are challenged by the heterogeneity of nutritional and clinical vitamin D guidelines, with respect to the diagnosis and treatment of vitamin D deficiency. We aimed to address this issue by providing respective recommendations for adults, developed by a European expert panel, using the Delphi method to reach consensus. Increasing the awareness of vitamin D deficiency and efforts to harmonize vitamin D guidelines should be pursued. We argue against a general screening for vitamin D deficiency but suggest 25-hydroxyvitamin D (25(OH)D) testing in certain risk groups. We recommend a vitamin D supplementation dose of 800 to 2000 international units (IU) per day for adults who want to ensure a sufficient vitamin D status. These doses are also recommended for the treatment of vitamin D deficiency, but higher vitamin D doses (e.g., 6000 IU per day) may be used for the first 4 to 12 weeks of treatment if a rapid correction of vitamin D deficiency is clinically indicated before continuing, with a maintenance dose of 800 to 2000 IU per day. Treatment success may be evaluated after at least 6 to 12 weeks in certain risk groups (e.g., patients with malabsorption syndromes) by measurement of serum 25(OH)D, with the aim to target concentrations of 30 to 50 ng/mL (75 to 125 nmol/L).

The Role of Vitamin D in Supporting Health in the COVID-19 Era

The genomic activity of vitamin D is associated with metabolic effects, and the hormone has a strong impact on several physiological functions and, therefore, on health. Among its renowned functions, vitamin D is an immunomodulator and a molecule with an anti-inflammatory effect, and, recently, it has been much studied in relation to its response against viral infections, especially against COVID-19. This review aims to take stock of the correlation studies between vitamin D deficiency and increased risks of severe COVID-19 disease and, similarly, between vitamin D deficiency and acute respiratory distress syndrome. Based on this evidence, supplementation with vitamin D has been tested in clinical trials, and the results are discussed. Finally, this study includes a biochemical analysis on the effects of vitamin D in the body's defense mechanisms against viral infection. In particular, the antioxidant and anti-inflammatory functions are considered in relation to energy metabolism, and the potential, beneficial effect of vitamin D in COVID-19 is described, with discussion of its influence on different biochemical pathways. The proposed, broader view of vitamin D activity could support a better-integrated approach in supplementation strategies against severe COVID-19, which could be valuable in a near future of living with an infection becoming endemic.

A Randomized, Open-Label Study to Assess Efficacy of Weekly Assumption of Cholecalciferol versus Calcifediol in Older Patients with Hypovitaminosis D

The aim of this single-center, open-label, randomized controlled study was to evaluate which formulation of vitamin D—between cholecalciferol and calcifediol—is most effective in the treatment of hypovitaminosis D in older adults. Demographic characteristics, clinical history, and comprehensive geriatric assessment were recorded at admission. Eligible patients were randomly assigned an equivalent vitamin D supplement, either with cholecalciferol or calcifediol, from the time of hospital admission to three months after discharge. Among the 140 older patients included (mean age 83 ± 6.6 years, 57.8% females), 69 received cholecalciferol and 71 received calcifediol. The mean plasma values of 25-hydroxyvitamin D3 (25OH-vitamin D3) found at the time of enrollment were 16.8 ± 9.9 ng/mL in patients receiving cholecalciferol and 18.8 ± 13.3 ng/mL in those treated with calcifediol (p = 0.31). At the three month follow-up, the mean concentration of 25OH-vitamin D3 was significantly higher in patients treated with calcifediol than in those receiving cholecalciferol (30.7 ± 8.4 vs. 45.4 ± 9.8 ng/mL, respectively; p < 0.001). Supplementation with either cholecalciferol or calcifediol effectively results in reaching the optimal circulating values of 25OH-vitamin D3 in older patients suffering from hypovitaminosis D. However, supplementation with calcifediol led to average circulating values of 25OH-vitamin D3 that were significantly higher (over 50%) than those obtained with cholecalciferol.

Real world evidence of calcifediol or vitamin D prescription and mortality rate of COVID-19 in a retrospective cohort of hospitalized Andalusian patients

COVID-19 is a major worldwide health problem because of acute respiratory distress syndrome, and mortality. Several lines of evidence have suggested a relationship between the vitamin D endocrine system and severity of COVID-19. We present a survival study on a retrospective cohort of 15,968 patients, comprising all COVID-19 patients hospitalized in Andalusia between January and November 2020. Based on a central registry of electronic health records (the Andalusian Population Health Database, BPS), prescription of vitamin D or its metabolites within 15-30 days before hospitalization were recorded. The effect of prescription of vitamin D (metabolites) for other indication previous to the hospitalization was studied with respect to patient survival. Kaplan-Meier survival curves and hazard ratios support an association between prescription of these metabolites and patient survival. Such association was stronger for calcifediol (Hazard Ratio, HR = 0.67, with 95% confidence interval, CI, of [0.50-0.91]) than for cholecalciferol (HR = 0.75, with 95% CI of [0.61-0.91]), when prescribed 15 days prior hospitalization. Although the relation is maintained, there is a general decrease of this effect when a longer period of 30 days prior hospitalization is considered (calcifediol HR = 0.73, with 95% CI [0.57-0.95] and cholecalciferol HR = 0.88, with 95% CI [0.75, 1.03]), suggesting that association was stronger when the prescription was closer to the hospitalization.

Vitamin D and acute and severe illness - a mechanistic and pharmacokinetic perspective

The COVID-19 pandemic has generated high interest in factors modulating risk of infection, disease severity and recovery. Vitamin D has received interest since it is known to modulate immune function and vitamin D deficiency is associated with increased risk of respiratory infections and adverse health outcomes in severely ill patients. There are no population representative data on the direct relationship between vitamin D status and SARS-CoV-2 infection risk and severity of COVID-19. Data from intervention studies are limited to 4 studies. Here we summarise findings regarding vitamin D status and metabolism and their alterations during severe illness, relevant to COVID-19 patients. Further, we summarise vitamin D intervention studies with respiratory disease outcomes and in critically ill patients and provide an overview of relevant patient and population guidelines. Vitamin D deficiency is highly prevalent in hospitalised patients, particularly when critically ill including those with COVID-19. Acute and critical illness leads to pronounced changes in vitamin D metabolism and status, suggestive of increased requirements. This needs to be considered in the interpretation of potential links between vitamin D status and disease risk and severity and for patient management. There is some evidence that vitamin D supplementation decreases the risk of respiratory tract infections, while supplementation of ICU patients has shown little effect on disease severity or length of treatment. Considering the high prevalence of deficiency and low risks associated with supplementation, pro-actively applying current population and patient management guidelines to prevent, monitor and correct vitamin D deficiency is appropriate.