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Calcium supplements and cancer risk: a meta-analysis of randomised controlled trials.
- Source :
- British Journal of Nutrition; 10/28/2013, Vol. 110 Issue 8, p1384-1393, 10p
- Publication Year :
- 2013
-
Abstract
- Some evidence suggests that Ca and vitamin D supplements affect cancer risk; however, it is uncertain whether the effects are due to Ca, vitamin D or the combination. We investigated the effect of Ca supplements without co-administered vitamin D on cancer risk. Medline, Embase and the Cochrane Central Register of Controlled Trials, reference lists of meta-analyses and two clinical trial registries were searched for randomised, placebo-controlled trials of Ca supplements ( ≥ 500 mg/d), with ≥ 100 participants and duration >1 year. The lead authors of eligible trials supplied data on cancer outcomes. Trial-level data were analysed using random-effects meta-analyses and patient-level data using Cox proportional hazards models. A total of sixteen trials were eligible, six had no data available, ten provided trial-level data (n 10 496, mean duration 3·9 years), and of these, four provided patient-level data (n 7221, median duration 3·5 years). In the meta-analysis of trial-level data, allocation to Ca did not alter the risk of total cancer (relative risk 0·95, 95 % CI 0·76, 1·18, P= 0·63), colorectal cancer (relative risk 1·38, 95 % CI 0·89, 2·15, P= 0·15), breast cancer (relative risk 1·01, 95 % CI 0·64, 1·59, P= 0·97) or cancer-related mortality (relative risk 0·96, 95 % CI 0·74, 1·24, P= 0·75), but reduced the risk of prostate cancer (relative risk 0·54, 95 % CI 0·30, 0·96, P= 0·03), although there were few events. The meta-analysis of patient-level data showed similar results, with no effect of Ca on the risk of total cancer (hazard ratio 1·07, 95 % CI 0·89, 1·28, P= 0·50). Ca supplements without co-administered vitamin D did not alter total cancer risk over 4 years, although the meta-analysis lacked power to detect very small effects, or those with a longer latency. [ABSTRACT FROM PUBLISHER]
- Subjects :
- CALCIUM
TUMOR prevention
TUMOR risk factors
CONFIDENCE intervals
DIETARY supplements
INFORMATION storage & retrieval systems
MEDICAL databases
MEDICAL information storage & retrieval systems
MEDLINE
META-analysis
PROBABILITY theory
RESEARCH funding
STATISTICAL hypothesis testing
TUMORS
SYSTEMATIC reviews
EVIDENCE-based medicine
PROFESSIONAL practice
RANDOMIZED controlled trials
DISEASE incidence
PROPORTIONAL hazards models
PUBLICATION bias
DATA analysis software
THERAPEUTICS
Subjects
Details
- Language :
- English
- ISSN :
- 00071145
- Volume :
- 110
- Issue :
- 8
- Database :
- Complementary Index
- Journal :
- British Journal of Nutrition
- Publication Type :
- Academic Journal
- Accession number :
- 90607365
- Full Text :
- https://doi.org/10.1017/S0007114513001050