Limits...
Vitamin D supplements and cancer incidence and mortality: a meta-analysis.

Keum N, Giovannucci E - Br. J. Cancer (2014)

Bottom Line: Observational studies suggest that effects of vitamin D may be stronger for cancer mortality than for incidence.Over 2-7 years of duration, vitamin D supplementations had little effect on total cancer incidence (400-1100 IU per day, summary relative risk (RR)=1.00, 95% confidence interval (CI)=0.94-1.06, I(2)=0%; four RCTs with combined 4333 cases), but significantly reduced total cancer mortality (400-833 IU per day, summary RR=0.88, 95% CI=0.78-0.98, I(2)=0%, three RCTs with combined 1190 deaths).Over 2-7 years of duration, the benefit of vitamin D supplementation may be limited to cancer mortality.

View Article: PubMed Central - PubMed

Affiliation: Departments of Nutrition and Epidemiology, Harvard School of Public Health, Building 2, 3rd floor, 655 Huntington Avenue, Boston, MA 02115, USA.

ABSTRACT

Background: Observational studies suggest that effects of vitamin D may be stronger for cancer mortality than for incidence. Yet, existing randomised controlled trials (RCTs) of vitamin D supplementation have limited power to examine the relationships as their primary end points are not cancer incidence or mortality.

Methods: Meta-analyses of RCTs of vitamin D supplementation and total cancer incidence and mortality were conducted.

Results: Over 2-7 years of duration, vitamin D supplementations had little effect on total cancer incidence (400-1100 IU per day, summary relative risk (RR)=1.00, 95% confidence interval (CI)=0.94-1.06, I(2)=0%; four RCTs with combined 4333 cases), but significantly reduced total cancer mortality (400-833 IU per day, summary RR=0.88, 95% CI=0.78-0.98, I(2)=0%, three RCTs with combined 1190 deaths).

Conclusions: Over 2-7 years of duration, the benefit of vitamin D supplementation may be limited to cancer mortality.

Show MeSH

Related in: MedlinePlus

Meta-analyses of RCTs of vitamin D supplementation and total cancer incidence and mortality. (A) Total cancer incidence, (B) total cancer mortality. Abbreviations: CI=confidence interval; RR=relative risk.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4150260&req=5

fig2: Meta-analyses of RCTs of vitamin D supplementation and total cancer incidence and mortality. (A) Total cancer incidence, (B) total cancer mortality. Abbreviations: CI=confidence interval; RR=relative risk.

Mentions: Four RCTs were included in the meta-analysis (4333 cases, 45 151 participants) (Table 1) (Trivedi et al, 2003; Wactawski-Wende et al, 2006; Lappe et al, 2007; Avenell et al, 2012). The summary RR for intervention vs control group was 1.00 (P=0.998, 95% CI=0.94–1.06) with no evidence of heterogeneity (I2=0%, Pheterogeneity=0.54) (Figure 2A). In a sensitivity analysis excluding WHI (Wactawski-Wende et al, 2006), the summary RR was 1.06 (P=0.33, 95% CI=0.94–1.21, I2=0%, Pheterogeneity=0.63). Small-study effects, such as publication bias, were not indicated in both primary (PEgger=0.84, PBegg>0.999) and sensitivity analyses (PEgger=0.32, PBegg=0.60).


Vitamin D supplements and cancer incidence and mortality: a meta-analysis.

Keum N, Giovannucci E - Br. J. Cancer (2014)

Meta-analyses of RCTs of vitamin D supplementation and total cancer incidence and mortality. (A) Total cancer incidence, (B) total cancer mortality. Abbreviations: CI=confidence interval; RR=relative risk.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4150260&req=5

fig2: Meta-analyses of RCTs of vitamin D supplementation and total cancer incidence and mortality. (A) Total cancer incidence, (B) total cancer mortality. Abbreviations: CI=confidence interval; RR=relative risk.
Mentions: Four RCTs were included in the meta-analysis (4333 cases, 45 151 participants) (Table 1) (Trivedi et al, 2003; Wactawski-Wende et al, 2006; Lappe et al, 2007; Avenell et al, 2012). The summary RR for intervention vs control group was 1.00 (P=0.998, 95% CI=0.94–1.06) with no evidence of heterogeneity (I2=0%, Pheterogeneity=0.54) (Figure 2A). In a sensitivity analysis excluding WHI (Wactawski-Wende et al, 2006), the summary RR was 1.06 (P=0.33, 95% CI=0.94–1.21, I2=0%, Pheterogeneity=0.63). Small-study effects, such as publication bias, were not indicated in both primary (PEgger=0.84, PBegg>0.999) and sensitivity analyses (PEgger=0.32, PBegg=0.60).

Bottom Line: Observational studies suggest that effects of vitamin D may be stronger for cancer mortality than for incidence.Over 2-7 years of duration, vitamin D supplementations had little effect on total cancer incidence (400-1100 IU per day, summary relative risk (RR)=1.00, 95% confidence interval (CI)=0.94-1.06, I(2)=0%; four RCTs with combined 4333 cases), but significantly reduced total cancer mortality (400-833 IU per day, summary RR=0.88, 95% CI=0.78-0.98, I(2)=0%, three RCTs with combined 1190 deaths).Over 2-7 years of duration, the benefit of vitamin D supplementation may be limited to cancer mortality.

View Article: PubMed Central - PubMed

Affiliation: Departments of Nutrition and Epidemiology, Harvard School of Public Health, Building 2, 3rd floor, 655 Huntington Avenue, Boston, MA 02115, USA.

ABSTRACT

Background: Observational studies suggest that effects of vitamin D may be stronger for cancer mortality than for incidence. Yet, existing randomised controlled trials (RCTs) of vitamin D supplementation have limited power to examine the relationships as their primary end points are not cancer incidence or mortality.

Methods: Meta-analyses of RCTs of vitamin D supplementation and total cancer incidence and mortality were conducted.

Results: Over 2-7 years of duration, vitamin D supplementations had little effect on total cancer incidence (400-1100 IU per day, summary relative risk (RR)=1.00, 95% confidence interval (CI)=0.94-1.06, I(2)=0%; four RCTs with combined 4333 cases), but significantly reduced total cancer mortality (400-833 IU per day, summary RR=0.88, 95% CI=0.78-0.98, I(2)=0%, three RCTs with combined 1190 deaths).

Conclusions: Over 2-7 years of duration, the benefit of vitamin D supplementation may be limited to cancer mortality.

Show MeSH
Related in: MedlinePlus