Information sourced from BMJ:
BMJ 2014;348:g1903
[Free full-text BMJ article PDF | PubMed® abstract]
Research
Vitamin D and risk of cause specific death: systematic review and meta-analysis of observational cohort and randomised intervention studies
Rajiv Chowdhury, Setor Kunutsor, Anna Vitezova, et al.
Correspondence to: R Chowdhury rajiv.chowdhury@phpc.cam.ac.uk or O H Franco o.franco@erasmusmc.nl
Abstract
Objective To evaluate the extent to which circulating biomarker and supplements of vitamin D are associated with mortality from cardiovascular, cancer, or other conditions, under various circumstances.
Design Systematic review and meta-analysis of observational studies and randomised controlled trials.
Data sources Medline, Embase, Cochrane Library, and reference lists of relevant studies to August 2013; [correspondence] with investigators.
Study selection Observational cohort studies and randomised controlled trials in adults, which reported associations between vitamin D (measured as circulating 25-hydroxyvitamin D concentration or vitamin D supplement given singly) and [cause-specific] mortality outcomes.
Data extraction Data were extracted by two independent investigators, and a consensus was reached with involvement of a third. Study specific relative risks from 73 cohort studies (849 412 participants) and 22 randomised controlled trials (vitamin D given alone versus placebo or no treatment; 30 716 participants) were meta-analysed using random effects models and were grouped by study and population characteristics.
Results In the primary prevention observational studies, comparing bottom versus top thirds of baseline circulating 25-hydroxyvitamin D distribution, pooled relative risks were 1.35 (95% confidence interval 1.13 to 1.61) for death from cardiovascular disease, 1.14 (1.01 to 1.29) for death from cancer, 1.30 (1.07 to 1.59) for non-vascular, non-cancer death, and 1.35 (1.22 to 1.49) for all cause mortality. Subgroup analyses in the observational studies indicated that risk of mortality was significantly higher in studies with lower baseline use of vitamin D supplements. In randomised controlled trials, relative risks for all cause mortality were 0.89 (0.80 to 0.99) for vitamin D3 supplementation and 1.04 (0.97 to 1.11) for vitamin D2 supplementation. The effects observed for vitamin D3supplementation remained unchanged when grouped by various characteristics. However, for vitamin D2 supplementation, increased risks of mortality were observed in studies with lower intervention doses and shorter average intervention periods.
Conclusions Evidence from observational studies indicates inverse associations of circulating 25-hydroxyvitamin D with risks of death due to cardiovascular disease, cancer, and other causes. Supplementation with vitamin D3 significantly reduces overall mortality among older adults; however, before any widespread supplementation, further investigations will be required to establish the optimal dose and duration and whether vitamin D3 and D2 have different effects on mortality risk.
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Alberto Reino
BackgroundBK viremia, a prerequisite for BK virus nephropathy (BKVN), affects 5% to 16% of pediatric renal transplant recipients (PRTR). We evaluated the safety and efficacy of a novel approach to treating BK viremia using fluoroquinolones and leflunomide in PRTR. MethodsWe studied 230 PRTR at Mattel Children's Hospital, UCLA, who underwent renal transplantation between January 2003 and October 2010. Nineteen patients were found to have BK viremia. Ciprofloxacin was started when the BK viral load was greater than 625 copies/mL, and patients were switched to leflunomide if BK viral load did not decrease after 2 months of ciprofloxacin therapy. All patients underwent transplant kidney biopsy, and their estimated glomerular filtration rate (eGFR) and BK PCR was measured serially. The side effects of ciprofloxacin and leflunomide were recorded in each patient. ResultsThere was a significant decrease in BK viral load in patients treated with ciprofloxacin and leflunomide (P<0.001) with only a small reduction in immunosuppression. BK viremia was associated with a significantly decreased eGFR (P<0.001), and treatment with ciprofloxacin and leflunomide was associated with improved eGFR (P<0.001). This approach resulted in a BKVN rate of only 1%. ConclusionsThis analysis demonstrates for the first time that, used in a stepwise fashion, ciprofloxacin and leflunomide are effective and safe treatments for BK viremia in PRTR.
