Hypocalcaemic cardiac failure post BMT secondary to unrecognized vitamin D deficiency

Insights Into the Role of Vitamin D as a Biomarker in Stem Cell Transplantation

Vitamin D was discovered 100 years ago and since then multiple studies have consistently proved its effect on bone health and mineral metabolism. Further research has also explored its so-called "non-classical" biological effects, encompassing immune regulation and control of cell proliferation and differentiation. Vitamin D downregulates pro-inflammatory immune cells and subsequently their cytokine production, while enhancing the anti-inflammatory subsets, thus mediating inflammation and fostering a more tolerogenic environment. Its biological action is exerted through the vitamin D receptor, a nuclear receptor that mediates gene transcription and is expressed in most cells from the innate and adaptive immunity. Owing to its immune-modulatory properties, its role in cancer pathophysiology, hematology disorders and stem cell transplantation has also been investigated. Vitamin D deficiency causes immune imbalance and cytokine dysregulation, contributing to some autoimmune diseases. In the hematopoietic stem cell transplant setting this could lead to complications such as acute and chronic graft-versus-host disease, ultimately impacting transplant outcomes. Other factors have also been linked to this, including specific polymorphisms of the vitamin D receptor in both stem cell donors and recipients. Nevertheless, studies thus far have shown conflicting results and the use of vitamin D or its receptor as biomarkers has not been validated yet, therefore there are no evidence-based consensus guidelines to guide clinicians in their day-to-day practice. To gain more insight in this topic, we have reviewed the existent literature and gathered the current evidence. This is an overview of the role of serum vitamin D and its receptor as biomarkers for clinical outcomes in patients undergoing hematopoietic stem cell transplantation. Further prospective studies with larger cohorts are warranted to validate the viability of using serum vitamin D, and its receptor, as biomarkers in potential stem cell donors and patients, to identify those at risk of post-transplant complications and enable early therapeutic interventions.

Current Practice in Vitamin D Management in Allogeneic Hematopoietic Stem Cell Transplantation: A Survey by the Transplant Complications Working Party of the European Society for Blood and Marrow Transplantation

Beyond its impact on bone health, numerous studies have investigated the immune-regulatory properties of vitamin D and shown how its deficiency can affect outcomes in allogeneic hematopoietic stem cell transplantation (HSCT), particularly in acute or chronic graft-versus-host disease. This survey, carried out by the Transplant Complications Working Party of the European Society for Blood and Marrow Transplantation (EBMT), describes the current clinical practice discrepancies across the EBMT HSCT programs. We therefore recommend the development of evidence-based guidelines to standardize evaluation criteria and to harmonize the management of vitamin D deficiency in patients undergoing allogeneic HSCT.

Correction of vitamin D deficiency in critically ill patients - VITdAL@ICU study protocol of a double-blind, placebo-controlled randomized clinical trial

BACKGROUND

Vitamin D deficiency is associated with multiple adverse health outcomes including increased morbidity and mortality in the general population and in critically ill patients. However, no randomized controlled trial has evaluated so far whether treatment with sufficiently large doses of vitamin D can improve clinical outcome of patients in an intensive care setting.

METHODS/DESIGN

The VITdAL@ICU trial is an investigator-initiated, non-commercial, double-blind, placebo-controlled randomized clinical trial. This study compares high-dose oral cholecalciferol (vitamin D3) versus placebo treatment in a mixed population of 480 critically ill patients with low 25-hydroxyvitamin-D levels at study enrollment (≤ 20ng/ml). Following an initial loading dose of 540,000 IU of vitamin D3, patients receive 90,000 IU of vitamin D3 on a monthly basis for 5 months. The study is designed to compare clinical outcome in the two study arms with the primary endpoint being length of hospital stay. Secondary endpoints include among others length of ICU stay, the percentage of patients with 25(OH)D levels > 30 ng/ml at day 7, ICU and hospital mortality and duration of mechanical ventilation. We describe here the VITdAL@ICU study protocol for the primary report.

DISCUSSION

This trial is designed to evaluate whether high-dose vitamin D3 is able to improve morbidity and mortality in a mixed population of adult critically ill patients and correct vitamin D deficiency safely.

TRIAL REGISTRATION

ClinicalTrials: NCT01130181.

Vitamin D and the critically ill patient

PURPOSE OF REVIEW

To summarize the current knowledge on vitamin D with a special focus on critically ill patients.

RECENT FINDINGS

Vitamin D deficiency is associated with adverse health outcomes including increased risk of cardiovascular disease, morbidity and mortality in the general population. In critically ill patients, the pleiotropic effects of vitamin D including its role in immune function are of great interest.

SUMMARY

To date, it is not clear whether vitamin D deficiency is a surrogate marker for increased morbidity or whether treatment with sufficiently large doses of vitamin D may improve patient outcome in an intensive care setting.

Vitamin D metabolism and deficiency in critical illness

Vitamin D deficiency is highly prevalent and has been associated with a diverse range of chronic medical conditions in the general population. In contrast, the prevalence, pathogenesis and significance of vitamin D deficiency have received little attention in acute medicine. Vitamin D deficiency is seldom considered and rarely corrected adequately, if at all, in critically ill patients. Recent recognition of the extra-skeletal, pleiotropic actions of vitamin D in immunity, epithelial function and metabolic regulation may underlie the previously under-recognized contribution of vitamin D deficiency to typical co-morbidities in critically ill patients, including sepsis, systemic inflammatory response syndrome and metabolic dysfunction. Improved understanding of vitamin D metabolism and regulation in critical illness may allow therapeutic exploitation of vitamin D to improve outcome in critically ill patients.

Short-term effects of high-dose oral vitamin D3 in critically ill vitamin D deficient patients: a randomized, double-blind, placebo-controlled pilot study

Introduction

Vitamin D deficiency is encountered frequently in critically ill patients and might be harmful. Current nutrition guidelines recommend very low vitamin D doses. The objective of this trial was to evaluate the safety and efficacy of a single oral high-dose vitamin D3 supplementation in an intensive care setting over a one-week observation period.

Methods

This was a randomized, double-blind, placebo-controlled pilot study in a medical ICU at a tertiary care university center in Graz, Austria. Twenty-five patients (mean age 62 ± 16yrs) with vitamin D deficiency [25-hydroxyvitamin D (25(OH)D) ≤20 ng/ml] and an expected stay in the ICU >48 hours were included and randomly received either 540,000 IU (corresponding to 13.5 mg) of cholecalciferol (VITD) dissolved in 45 ml herbal oil or matched placebo (PBO) orally or via feeding tube.

Results

The mean serum 25(OH)D increase in the intervention group was 25 ng/ml (range 1-47 ng/ml). The highest 25(OH)D level reached was 64 ng/ml, while two patients showed a small (7 ng/ml) or no response (1 ng/ml). Hypercalcemia or hypercalciuria did not occur in any patient. From day 0 to day 7, total serum calcium levels increased by 0.10 (PBO) and 0.15 mmol/L (VITD; P < 0.05 for both), while ionized calcium levels increased by 0.11 (PBO) and 0.05 mmol/L (VITD; P < 0.05 for both). Parathyroid hormone levels decreased by 19 and 28 pg/ml (PBO and VITD, ns) over the seven days, while 1,25(OH)D showed a transient significant increase in the VITD group only.

Conclusions

This pilot study shows that a single oral ultra-high dose of cholecalciferol corrects vitamin D deficiency within 2 days in most patients without causing adverse effects like hypercalcemia or hypercalciuria. Further research is needed to confirm our results and establish whether vitamin D supplementation can affect the clinical outcome of vitamin D deficient critically ill patients.

EudraCT Number

2009-012080-34

German Clinical Trials Register (DRKS)

DRKS00000750

Vitamin D deficiency in the intensive care unit: an invisible accomplice to morbidity and mortality?

The association between vitamin D deficiency and chronic illness is well-known. Vitamin D deficiency has been associated with increased mortality in the general population. Despite this knowledge, vitamin D insufficiency is seldom considered and rarely replaced adequately, if at all, in critically ill patients in intensive care. We present a hypothetic model demonstrating how vitamin D deficiency may be an unrecognized contributor to adverse outcome in intensive care patients.