Vitamin D supplementation and breast cancer prevention: a systematic review and meta-analysis of randomized clinical trials
- PMID: 23894438
- PMCID: PMC3718745
- DOI: 10.1371/journal.pone.0069269
Vitamin D supplementation and breast cancer prevention: a systematic review and meta-analysis of randomized clinical trials
Abstract
In recent years, the scientific evidence linking vitamin D status or supplementation to breast cancer has grown notably. To investigate the role of vitamin D supplementation on breast cancer incidence, we conducted a systematic review and meta-analysis of randomized controlled trials comparing vitamin D with placebo or no treatment. We used OVID to search MEDLINE (R), EMBASE and CENTRAL until April 2012. We screened the reference lists of included studies and used the "Related Article" feature in PubMed to identify additional articles. No language restrictions were applied. Two reviewers independently extracted data on methodological quality, participants, intervention, comparison and outcomes. Risk Ratios and 95% Confident Intervals for breast cancer were pooled using a random-effects model. Heterogeneity was assessed using the I(2) test. In sensitivity analysis, we assessed the impact of vitamin D dosage and mode of administration on treatment effects. Only two randomized controlled trials fulfilled the pre-set inclusion criteria. The pooled analysis included 5372 postmenopausal women. Overall, Risk Ratios and 95% Confident Intervals were 1.11 and 0.74-1.68. We found no evidence of heterogeneity. Neither vitamin D dosage nor mode of administration significantly affected breast cancer risk. However, treatment efficacy was somewhat greater when vitamin D was administered at the highest dosage and in combination with calcium (Risk Ratio 0.58, 95% Confident Interval 0.23-1.47 and Risk Ratio 0.93, 95% Confident Interval 0.54-1.60, respectively). In conclusions, vitamin D use seems not to be associated with a reduced risk of breast cancer development in postmenopausal women. However, the available evidence is still limited and inadequate to draw firm conclusions. Study protocol code: FARM8L2B5L.
Conflict of interest statement
Figures
References
-
- Grant WB (2003) Ecologic studies of solar UV-B radiation and cancer mortality rates. Recent Results. Cancer Res 164: 371–377. - PubMed
-
- Zittermann A, Schleithoff SS, Koerfer R (2005) Putting vitamin D and cardiovascular diseases into perspective. Br J Nutr 94(4): 483–492. - PubMed
-
- Holick MF (2004) Vitamin D: importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis. Am J Clin Nutr 79: 362–71. - PubMed
-
- Giovannucci E (2005) The epidemiology of vitamin D and cancer incidence and mortality: a review (United States). Cancer Causes Control 16: 83–95. - PubMed
-
- Garland CF, Grant W, Mohr SB, Gorham ED, Garland FC (2007) What is the dose-response relationship between vitamin D and cancer risk? Nutr Rev 65: S91–5. - PubMed
Publication types
MeSH terms
Substances
LinkOut - more resources
Full Text Sources
Other Literature Sources
Medical
Miscellaneous
