Vitamin D Supplementation

Author and Year:
Schroten NF, Ruifrok WP et al, 2013
PubMed ID:
Article Title:
Short-term vitamin D3 supplementation lowers plasma renin activity in patients with stable chronic heart failure: An open-label, blinded end point, randomized prospective trial (VitD-CHF trial).
Schroten F, Ruifrok WP, Kleijn L, Dokter MM, Silljé H, Lambers Heerspink HJ, Bakker SJ, Kema IP, van Gilst WH, van Veldhuisen DJ, Hillege HL, de Boer RA.
American Heart Journal, 2013; 166: 357-364.
Year of publication:
Page numbers:
Study Design:
Randomized Controlled Trial
Risk of Bias Assessment Rating:
Inclusion Criteria:
Patients with chronic heart failure (CHF) on optimal medical therapy. Treated with an angiotensin-converting enzyme inhibitor (ACEi) at a stable dose (at least enalapril 10mg daily or any other ACEi in an equivalent dose or maximum tolerated dose) or, if intolerant to ACEi, with an angiotensin receptor blocker (ARB) (candesartan, eight mg daily or any other ARB in an equivalent dose or maximum tolerated dose) for at least four weeks before the baseline visit (i.e., Visit 1). Treated with a beta-blocker unless contraindicated or not tolerated at a stable dose for at least four weeks before Visit 1.
Exclusion Criteria:
Use of VitD supplements, drugs with known interaction with VitD homeostasis (oralcorticosteroids, thyroxin, anti-epileptics, tetracyclines or quinolones) or direct renin inhibitors Hypersensitivity to study drug Phenylketonuria or fructose intolerance Current acute decompensated heart (HF) Hypercalcemia Hypercalciuria Glomerular filtra GFR less than 60 Nephrolithiasis or sarcoidosis; acute coronary syndrome, CVA, TIA, cardiac, carotid or major vascular surgery, percutaneous coronary intervention or carotid angioplasty (either within the past three months or planned); right HF due to severe pulmonary disease; Dx of peripartum or chemotherapy-induced cardiomyopathy within last year; heart transplant, on transplant list or with left ventricular assistance device; untreated ventricula arrhythmia with syncopal episodes within past 3 months; ventricular tachycardia or fibrillation without internal cardiac defibrillator; symptomatic bradycardia **remainder can be found in study
Research Purpose:
In this trial, we studied the effect of short-term, high-dose cholecalciferol [vitamin D3 (VitD3)], on PRA in CHF patients on optimal CHF medication. We hypothesized that high-dose VitD3 lowers PRA.
Blinding efforts:
Investigators were blnded to PRA and PRC results and the outcome analyses were conducted in a blinded fashion.
Study Location:
Groningen, the Netherlands
Source(s) of Funding:
Please specify names of funders:
Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? No
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? Yes
5. Was blinding used to prevent introduction of bias? Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? Yes
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) Yes
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  6.6. Were extra or unplanned treatments described? Yes
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? No
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? No
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? Yes
  8.6. Was clinical significance as well as statistical significance reported? No
  8.7. If negative findings, was a power calculation reported to address type 2 error? No
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes