Administration of vitamin D and its metabolites in critically ill adult patients: an updated systematic review with meta-analysis of randomized controlled trials

Efficacy and safety of enteral supplementation with high-dose vitamin D in critically ill patients with vitamin D deficiency

BACKGROUND

Vitamin D deficiency is associated with mortality and morbidity in critically ill patients. This study investigated the safety and effectiveness of enteral high-dose vitamin D supplementation in intensive care unit (ICU) patients in Asia.

METHODS

This was a multicenter, prospective, randomized-controlled study. Eligible participants with vitamin D deficiency were randomly assigned to the control or vitamin D supplementation group. In the vitamin D supplementation group, the patients received 569,600 IU vitamin D. The primary outcome was the serum 25(OH)D level on day 7.

RESULTS

41 and 20 patients were included in the vitamin D supplementation and control groups, respectively. On day 7, the serum 25(OH)D level was significantly higher in the vitamin D supplementation group compared to the control group (28.5 [IQR: 20.2-52.6] ng/mL and 13.9 [IQR: 11.6-18.8] ng/mL, p < 0.001). Only 41.5% of the patients achieved serum 25(OH)D levels higher than 30 ng/mL in the supplementation group. This increased level was sustained in the supplementation group on both day 14 and day 28. There were no significant adverse effects noted in the supplementation group. Patients who reached a serum 25(OH)D level of >30 ng/mL on day 7 had a significantly lower 30-day mortality rate than did those who did not (5.9% vs 37.5%, p < 0.05).

CONCLUSIONS

In our study, less than half of the patients reached adequate vitamin D levels after the enteral administration of high-dose vitamin D. A reduction in 30-day mortality was noted in the patients who achieved adequate vitamin D levels. TRIAL REGISTRATION CLINICALTRIALS.

GOV ID

NCT04292873, Registered, March 1, 2020.

Outcomes of High-Dose Versus Low-Dose Vitamin D on Prognosis of Sepsis Requiring Mechanical Ventilation: A Randomized Controlled Trial

Background: Critically ill patients with sepsis have a high incidence of vitamin D deficiency. Vitamin D promotes the synthesis of human cathelicidin antimicrobial peptide, a precursor of LL-37, which is a part of the innate immune system. This study investigated the effectiveness and safety of the early administration of high-dose enteral vitamin D3 in comparison with low-dose vitamin D3 in patients with sepsis requiring mechanical ventilation (MV). Methods: Eighty adult patients with sepsis requiring MV with known vitamin D deficiency were randomly assigned to receive either an enteral 50 000 IU (Group I) or 5000 IU (Group II) vitamin D supplementation. Clinical and laboratory parameters were evaluated at baseline and on days 4 and 7 between the study groups. The change in serum procalcitonin (PCT) levels on day 7 was the primary outcome, while the change in serum LL-37 levels on day 7, changes in sequential organ failure assessment (SOFA) score, and clinical pulmonary infection score on day 7, MV duration, and hospital length of stay (LOS) were the secondary outcomes. Results: The (day 7-day 0) change in serum PCT and LL-37 levels and SOFA score were significantly different in Group I (P = .010, P < .001, and P < .001, respectively). The SOFA score was significantly different on days 4 and 7 in Group I (P < .001 and P < .001, respectively). The incidence of early ventilator-associated pneumonia was significantly different between both treatment groups (P = .025). The hospital LOS was shorter in Group I (P < .001). No 25-hydroxyvitamin-D toxicity was observed in either group. Conclusions: Early enteral administration of high-dose vitamin D3 in critically ill patients with sepsis requiring MV along with standard treatment for sepsis decreased serum procalcitonin levels, increased serum LL-37 levels, and ameliorated illness severity scores.

Vitamin D metabolism in critically ill patients with acute kidney injury: a prospective observational study

BACKGROUND

Vitamin D deficiency in critically ill patients is associated with poor outcomes, and vitamin D supplementation is recommended for patients with chronic kidney disease. Whether acute kidney injury (AKI) is associated with altered Vitamin D metabolism is unknown. We aimed to compare the longitudinal profiles of serum 25(OH)D and 1,25(OH)2D concentrations in critically ill patients with and without moderate to severe AKI and explore the impact of renal recovery and parathyroid hormone (PTH).

METHODS

In this prospective, observational study in two centres in the UK, critically ill patients with and without AKI underwent serial measurement of serum 25(OH)D and 1,25(OH)2D and plasma PTH concentrations for 5 days. Linear mixed model analysis and sensitivity analyses were performed.

RESULTS

Serial data of 137 patients were analysed. Seventy-one patients had AKI stage II/III of whom 23 recovered kidney function during the 5-day study period; 66 patients did not have AKI at enrolment of whom 14 developed new AKI. On day of enrolment, patients' serum 25(OH)D concentrations were low (median 18 nmol/L) but there was no significant difference between patients with and without AKI. Median serum 1,25(OH)2D levels were significantly lower in patients with AKI II/III (41 pmol/L [IQR 26, 58]) compared to similarly unwell patients without AKI (54 pmol/L [IQR 33, 69]) during the 5-day period. Recovery of kidney function in patients with AKI was associated with a rise in 1,25(OH)2D concentrations. Plasma PTH results were impacted by serum calcium and magnesium levels but not associated with 1,25(OH)2D levels.

CONCLUSIONS

Critically ill patients with moderate-to-severe AKI have significantly lower serum 1,25(OH)2D concentrations than similarly sick patients without AKI but there was no difference in serum 25(OH)D concentrations. Recovery of AKI was associated with a rise in serum 1,25(OH)2D concentrations. More research is needed to investigate the health benefits and safety of supplementation with active vitamin D in critically ill patients with moderate-to-severe AKI. Trial registration Clinicaltrials.gov (NCT02869919), registered on 16 May 2016.

Micronutrients as therapy in critical illness

PURPOSE OF REVIEW

Recent large-scale randomized controlled trials (RCTs) challenged current beliefs about the potential role of micronutrients to attenuate the inflammatory response and improve clinical outcomes of critically ill patients. The purpose of this narrative review is to provide an overview and critical discussion about most recent clinical trials, which evaluated the clinical significance of a vitamin C, vitamin D, or selenium administration in critically ill patients.

RECENT FINDINGS

None of the most recent large-scale RCTs could demonstrate any clinical benefits for a micronutrient administration in ICU patients, whereas a recent RCT indicated harmful effects, if high dose vitamin C was administered in septic patients. Following meta-analyses could not confirm harmful effects for high dose vitamin C in general critically ill patients and indicated benefits in the subgroup of general ICU patients with higher mortality risk. For vitamin D, the most recent large-scale RCT could not demonstrate clinical benefits for critically ill patients, whereas another large-scale RCT is still ongoing. The aggregated and meta-analyzed evidence highlighted a potential role for intravenous vitamin D administration, which encourages further research. In high-risk cardiac surgery patients, a perioperative application of high-dose selenium was unable to improve patients' outcome. The observed increase of selenium levels in the patients' blood did not translate into an increase of antioxidative or anti-inflammatory enzymes, which illuminates the urgent need for more research to identify potential confounding factors.

SUMMARY

Current data received from most recent large-scale RCTs could not demonstrate clinically meaningful effects of an intervention with either vitamin C, vitamin D, or selenium in critically ill patients. More attention is needed to carefully identify potential confounding factors and to better evaluate the role of timing, duration, and combined strategies.

Should I Supplement Vitamin D in a Patient With Sepsis?

Sepsis is a potentially fatal organ failure produced by the host's immune response to infection. It is critical to identify risk factors associated with a poor prognosis in septic patients in order to develop new therapy options. Vitamin D deficiency (25-hydroxyvitamin cholecalciferol < 20 ng/mL) is common in critical and septic patients. Serum vitamin D concentrations are associated with an increased incidence of mortality in critically ill adult patients. In critically ill patients, vitamin D supplementation (a very high vitamin D 3 or cholecalciferol loading dosage as a single bolus dose ranging from 400,000 to 540,000 IU) is feasible and safe. Some of the trials and their post-hoc analyses evaluating vitamin D supplementation in severely sick individuals, including septic patients, suggested possible benefits in mortality (reduced 28-day mortality in the range of 8.1%-17.5%), and other outcomes (reduction in hospital length in the range from 9 to 18 days, and decrease in duration of mechanical ventilation in the range from 5 to 10 days). Despite the fact that many studies support the provision of vitamin D to septic patients, there are still many studies that contradict this opinion, and there is still debate about the recommendation to use vitamin D in sepsis. A pragmatic clinical approach in severe sepsis could be supplementation of vitamin D if serum levels are diminished (< 30 ng/mL). It appears that a single ultrahigh dose of vitamin D 3 (cholecalciferol) could be administered to the septic patient via an enteral tube, followed by daily or monthly maintenance doses. Parenteral administration might be reserved for a subgroup of septic patients with gastrointestinal, hepatic, or renal dysfunction. Future clinical trials designed exclusively for septic patients are required to assess the potential advantages of vitamin D. Possible impacts of selective activators of vitamin D receptors, such as paricalcitol, should be elucidated in sepsis. This emphasizes the requirement for more study and confirmation of any potential beneficial effects of vitamin D in sepsis.

Pharmacological evaluation of vitamin D in COVID-19 and long COVID-19: recent studies confirm clinical validation and highlight metformin to improve VDR sensitivity and efficacy

Nearly four years after its first appearance, and having gone from pandemic to endemic, the SARS-CoV-2 remains out of control globally. The purpose of this study was to evaluate the clinical efficacy of vitamin D (VD) in COVID-19 and long COVID-19, explain the discrepancy in clinical outcomes and highlight the potential impact of metformin on VD efficacy in recent articles. Articles from January 2022 to August 2023 were selected for this review. The objective of this study was achieved by reviewing, analyzing, and discussing articles demonstrating (1) the mechanism of action of VD (2) observational or randomized clinical trials (RCTs) that support or not the beneficial clinical effects of VD in COVID-19 or long COVID. (3) genetic and non-genetic reasons for the variation in the effects of VD. Articles were collected from electronic databases such as PubMed, Scopus, MEDLINE, Google Scholar, Egyptian Knowledge Bank, Science Direct, and Cochrane Database of Systematic Reviews. Twenty three studies conducted in vitro or in animal models indicated that VD may act in COVID-19 through protecting the respiratory system by antimicrobial peptide cathelicidins, reducing lung inflammation, regulating innate and adaptive immune functions and up regulation of autophagy gene activity. Our review identified 58 clinical studies that met the criteria. The number of publications supporting a beneficial clinical activity of VD in treating COVID-19 was 49 (86%), including 12 meta-analyses. Although the total patients included in all articles was 14,071,273, patients included in publications supporting a beneficial role of VD in COVID-19 were 14,029,411 (99.7%). Collectively, extensive observational studies indicated a decisive relationship between low VD levels and the severity of COVID-19 and mortality outcomes. Importantly, evidence from intervention studies has demonstrated the effectiveness of VD supplements in treating COVID-19. Furthermore, the results of 4 observational studies supported the beneficial role of VD in alleviating symptoms of long COVID-19 disease. However, eight RCTs and one meta-analysis of RCTs may contain low-grade evidence against a beneficial role of VD in COVID-19. Twenty-five articles have addressed the association between VDR and DBP genetic polymorphisms and treatment failure of VD in COVID-19. Impaired VDR signaling may underlie the variability of VD effects as non-genetic mechanisms. Interestingly, in recent studies, metformin has a beneficial therapeutic role in COVID-19 and long COVID-19, possibly by improving AMPK signaling of the VDR and enhancing the efficacy of the VD. In conclusion, evidence has been significantly strengthened over the past 18 months, with several meta-analyses and RCTs reporting conclusive beneficial effects of VD supplementation against COVID-19 and highlighting metformin to improve VDR sensitivity and efficacy in treating COVID-19 and long COVID-19.

Update on vitamin D role in severe infections and sepsis

Severe infections frequently require admission to the intensive care unit and cause life-threatening complications in critically ill patients. In this setting, severe infections are acknowledged as prerequisites for the development of sepsis, whose pathophysiology implies a dysregulated host response to pathogens, leading to disability and mortality worldwide.Vitamin D is a secosteroid hormone that plays a pivotal role to maintain immune system homeostasis, which is of paramount importance to resolve infection and modulate the burden of sepsis. Specifically, vitamin D deficiency has been widely reported in critically ill patients and represents a risk factor for the development of severe infections, sepsis and worse clinical outcomes. Several studies have demonstrated the feasibility, safety and effectiveness of vitamin D supplementation strategies to improve vitamin D body content, but conflictual results support its benefit in general populations of critically ill patients. In contrast, small randomised clinical trials reported that vitamin D supplementation may improve host-defence to pathogen invasion via the production of cathelicidin and specific cytokines. Nonetheless, no large scale investigations have been designed to specifically assess the impact of vitamin D supplementation on the outcome of critically ill septic patients admitted to the intensive care unit.

The science of micronutrients in clinical practice - Report on the ESPEN symposium

BACKGROUND & AIMS

The European Society for Clinical Nutrition and Metabolism published its first clinical guidelines for use of micronutrients (MNs) in 2022. A two-day web symposium was organized in November 2022 discussing how to apply the guidelines in clinical practice. The present paper reports the main findings of this symposium.

METHODS

Current evidence was discussed, the first day being devoted to clarifying the biology underlying the guidelines, especially regarding the definition of deficiency, the impact of inflammation, and the roles in antioxidant defences and immunity. The second day focused on clinical situations with high prevalence of MN depletion and deficiency.

RESULTS

The importance of the determination of MN status in patients at risk and diagnosis of deficiencies is still insufficiently perceived, considering the essential role of MNs in immune and antioxidant defences. Epidemiological data show that deficiencies of several MNs (iron, iodine, vitamin D) are a global problem that affects human health and well-being including immune responses such as to vaccination. Clinical conditions frequently associated with MN deficiencies were discussed including cancer, obesity with impact of bariatric surgery, diseases of the gastrointestinal tract, critical illness, and aging. In all these conditions, MN deficiency is associated with worsening of outcomes. The recurrent problem of shortage of MN products, but also lack of individual MN-products is a worldwide problem.

CONCLUSION

Despite important progress in epidemiology and clinical nutrition, numerous gaps in practice persist. MN depletion and deficiency are frequently insufficiently searched for in clinical conditions, leading to inadequate treatment. The symposium concluded that more research and continued education are required to improve patient outcome.

[Laboratory and calorimetric monitoring of medical nutrition therapy in intensive and intermediate care units : Second position paper of the Section Metabolism and Nutrition of the German Interdisciplinary Association for Intensive Care and Emergency Medicine (DIVI)]

This second position paper of the Section Metabolism and Nutrition of the German Interdisciplinary Association for Intensive Care and Emergency Medicine (DIVI) provides recommendations on the laboratory monitoring of macro- and micronutrient intake as well as the use of indirect calorimetry in the context of medical nutrition therapy of critically ill adult patients. In addition, recommendations are given for disease-related or individual (level determination) substitution and (high-dose) pharmacotherapy of vitamins and trace elements.

Micronutrient intake to protect against osteoporosis during and after critical illness

PURPOSE OF REVIEW

Improved survival from critical illness has enhanced the focus on ways to augment functional outcomes following discharge from the Intensive Care Unit. An area that is gaining increased attention is the effect of critical illness on bone health and fragility fractures following the episode. This review discusses the micronutrients that may play a role in bone metabolism and the potential benefits of their supplementation to prevent osteoporosis. These include calcium, phosphorous, magnesium, vitamin D, vitamin C, vitamin K, and certain trace elements.

FINDINGS

Although there is sound physiological basis for the involvement of these micronutrients in bone health and fracture prevention, there are few clinically relevant publications in this area with calcium and vitamin D being the best studied to date.

SUMMARY

In the absence of high-quality evidence in critically ill populations, attention to measurement and supplementation of these micronutrients as per current guidelines outlining micronutrient requirements in enteral and parenteral nutrition might mitigate bone loss and its sequelae in the recovery phase from critical illness.

Vitamin D Supplementation during Intensive Care Unit Stay Is Associated with Improved Outcomes in Critically Ill Patients with Sepsis: A Cohort Study

BACKGROUND

Vitamin D, as a common micronutrient, has been widely used in critically ill patients. However, whether supplementation of vitamin D in adult patients with sepsis can improve their prognosis remains controversial.

METHODS

Data from the Mart for Intensive Care IV database was used in this retrospective cohort study, and adult patients with sepsis were enrolled. Critically ill patients, admitted to intensive care units (ICUs) between 2008 and 2019 at the Beth Israel Deaconess Medical Center (BIDMC), were divided into the vitamin D supplementation group and non-vitamin D supplementation group. The primary outcomes were defined as all-cause in-hospital, 28-day, and 90-day mortality rates after admission to the ICU. A 1:1 propensity score matching (PSM), inverse probability of treatment weighting (IPTW), and overlap weighting (OW) analyses were used to minimize selection bias and balance the baseline demographic characteristics. Regression and survival analyses were performed to assess the association between vitamin D supplementation and clinical outcomes in patients with sepsis.

RESULTS

In total, 3539 patients with sepsis were enrolled as study participants; of these, 315 were supplemented with vitamin D during their ICU stay. In-hospital, 28-day, and 90-day mortality rates were significantly lower in patients with sepsis supplemented with vitamin D. Multivariate regression analysis showed vitamin D supplementation as a potential protective factor for in-hospital mortality with an odds ratio (OR) = 0.70 (0.51-0.96) after adjusting for all confounders. The hazard ratios (HRs) for 28-day and 90-day mortality were 0.65 (0.50-0.85) and 0.70 (0.55-0.90), respectively. The survival analysis showed that the vitamin D supplementation group had a higher survival probability within 28 and 90 days (p-value < 0.05). These results remained relatively stable post PSM, IPTW, and OW. However, we found no evidence that vitamin D supplementation could shorten the length of stay in the ICU or hospital.

CONCLUSIONS

Vitamin D supplementation during an ICU stay was associated with improved prognosis in patients with sepsis, as evidenced by lower in-hospital, 28-day, and 90-day mortality rates and lower disease severity-related scores, but showed no influence on the length of stay in the hospital or ICU.

Vitamin D receptor (VDR) on the cell membrane of mouse macrophages participates in the formation of lipopolysaccharide tolerance: mVDR is related to the effect of artesunate to reverse LPS tolerance

It is unclear whether membrane vitamin D receptor (mVDR) exists on the macrophage membrane or whether mVDR is associated with lipopolysaccharide (LPS) tolerance. Herein, we report that interfering with caveolae and caveolae-dependent lipid rafts inhibited the formation of LPS tolerance. VDR was detected as co-localized with membrane molecular markers. VDR was detected on the cell membrane and its level was higher in LPS-tolerant cells than that in only LPS treatment cells. Anti-VDR antibodies could abolish the effect of artesunate (AS) to reverse LPS tolerance, and the wild-type peptides (H397 and H305) of VDR, but not the mutant peptide (H397D and H305A), led to the loss of AS's effect. AS decreased the mVDR level in LPS-tolerant cells. In vivo, AS significantly reduced VDR level in the lung tissue of LPS-tolerant mice. In summary, mVDR exists on the cell membrane of macrophages and is closely associated with the formation of LPS tolerance and the effects of AS. Video Abstract.

[Vitamin C and D supplementation in critically ill patients]

Micronutrient supplementation as part of the medical nutrition therapy for critically ill patients has received much attention in the past few years. Nevertheless, in clinical practice uncertainty remains about the optimal supplementation strategy, including which substance at which dosage should be administered at what time to specific groups of patients. Thus, the aim of this narrative review is to summarize the current evidence and recommendations for the micronutrients vitamin C and vitamin D. The physiological and pathophysiological roles of both vitamins are presented, recently published clinical trials are discussed, and the recommendations of the current guidelines are summarized. In addition, pragmatic tips for use in everyday clinical practice in the intensive care unit are given.

Genetic Variations of the Vitamin D Metabolic Pathway and COVID-19 Susceptibility and Severity: Current Understanding and Existing Evidence

The immunomodulatory and metabolic effects of vitamin D receptor (VDR) activation have been considered beneficial in mitigating the susceptibility and severity of COVID-19 infection. Furthermore, vitamin D-binding protein (DBP) has pleiotropic effects on the immune system that may influence inflammation associated with COVID-19. Multiple observational studies have demonstrated an association between low levels of serum 25-hydroxyvitamin D and risk and the severity of COVID-19 infection. However, the impact of vitamin D supplementation as an adjunctive treatment for COVID-19 based on evidence from randomized clinical trials is unclear. Equally important is that certain variations of the genes involved in the vitamin D metabolic pathway have been shown to affect immune function and linked with various clinical outcomes, including cardio-metabolic disorders, autoimmune diseases, infections, and cancers. This indicates inter-individual difference in body response to vitamin D. There is also emerging evidence that common polymorphisms of these genes may influence the susceptibility and severity of COVID-19, although the confidence of these findings is limited by a small number of studies and participants. Further studies are needed to address the potential role of VDR activation and DBP in the pathophysiology of COVID-19 which take into account the genetic variations of vitamin D metabolic pathway.

An update of the effects of vitamins D and C in critical illness

Many critically ill patients are vitamin D and vitamin C deficient and the current international guidelines state that hypovitaminoses should be compensated. However, uncertainty about optimal dosage, timing and indication exists in clinical routine, mainly due to the conflicting evidence. This narrative review discusses both micronutrients with regards to pathophysiology, clinical evidence of benefits, potential risks, and guideline recommendations. Evidence generated from the most recent clinical trials are summarized and discussed. In addition, pragmatic tips for the application of these vitamins in the clinical routine are given. The supplementations of vitamin D and C represent cost-effective and simple interventions with excellent safety profiles. Regarding vitamin D, critically ill individuals require a loading dose to improve 25(OH)D levels within a few days, followed by a daily or weekly maintenance dose, usually higher doses than healthy individuals are needed. For vitamin C, dosages of 100-200 mg/d are recommended for patients receiving parenteral nutrition, but needs may be as high as 2-3 g/d in acutely ill patients.

Vitamin D Status and Potential Therapeutic Options in Critically Ill Patients: A Narrative Review of the Clinical Evidence

Vitamin D covers roles of paramount importance in the regulation of multiple physiological pathways of the organism. The metabolism of vitamin D involves kidney-liver crosstalk and requires an adequate function of these organs, where vitamin D is progressively turned into active forms. Vitamin D deficiency has been widely reported in patients living in the community, being prevalent among the most vulnerable subjects. It has been also documented in many critically ill patients upon admission to the intensive care unit. In this context, vitamin D deficiency may represent a risk factor for the development of life-threatening clinical conditions (e.g., infection and sepsis) and worse clinical outcomes. Several researchers have investigated the impact of vitamin D supplementation showing its feasibility, safety, and effectiveness, although conflicting results have put into question its real benefit in critically ill patients. The existing studies included heterogeneous critically ill populations and used slightly different protocols of vitamin D supplementation. For these reasons, pooling up the results is difficult and not conclusive. In this narrative review, we described vitamin D physiology and the pathophysiology of vitamin D depletion with a specific focus on critically ill patients with liver dysfunction, acute kidney injury, acute respiratory failure, and sepsis.