Nutritional Advice El Mondo
Objectives:
Protective effects of calcium supplementation against colorectal adenomas have been documented in systematic reviews; however, the results have not been conclusive. Therefore, this review article (meta-analysis) has been conducted.
Does calcium supplementation reduce colorectal adenomas?
Study design:
This review article included 5 RCTs involving 2,234 patients with a history of adenomas.
Based on visual inspection of the funnel plots as well as on quantitative measurement that used the Egger regression test, there was weak evidence of publication bias.
No major serious adverse events were associated with the use of calcium, but there was an increase in the incidence of hypercalcemia [p = 0 .0095].
Random errors were evaluated with trial sequential analyses (TSAs). However, TSA indicated a lack of firm evidence for a beneficial effect of calcium supplementation.
Results and conclusions:
The investigators found quantitative pooling of results from all 5 RCTs indicated that the use of supplemental calcium lasting 3 to 5 years showed a statistically significant 17% reduction in risk of any recurrent colorectal adenomas [RR = 0.83, 95% CI = 0.75-0.93, I2 = 8.5%, p = 0.36].
The investigators found in the sensitivity analysis of 3 trials with low bias risk a statistically significant 12% reduction in the recurrence of any colorectal adenomas [RR = 0.88, 95% CI = 0.79-0.99, I2 = 0%, p = 0.54] in patients who were administered supplemental calcium versus placebo.
The investigators found no association between supplemental calcium and recurrence of advanced colorectal adenomas in trials with low risk of bias [RR = 1.02, 95% CI = 0.67-1.55, I2 = 17.5%].
The investigators found in the subgroup analysis of 3 trials with elemental calcium dose ≤ 1200 mg/day, a statistically significant 16% reduction in the recurrent of any colorectal adenomas [RR = 0.84, 95% CI = 0.73-0.97, I2 = 38.5%, p = 0 .19].
However, a greater reduction of 26% [RR = 0.74, 95% CI = 0.56-0.97, I2 = 0%, p = 0 .70] was observed in the subgroup analysis of 2 trials with elemental calcium dose ≥ 1600 mg/day.
Subgroup analyses demonstrated no statistically significant association with the reduction of advanced colorectal adenomas in any doses.
The investigators concluded the available good quality RCTs suggests a possible beneficial effect of calcium supplementation – preferably at least 1600 mg/day elemental calcium – on the recurrence of colorectal adenomas. However, TSA indicated that the accumulated evidence is still inconclusive. Therefore, large well-designed randomized trials with low risk of bias are needed.
Original title:
Effects of calcium on the incidence of recurrent colorectal adenomas: A systematic review with meta-analysis and trial sequential analysis of randomized controlled trials by Veettil SK, Ching SM, […], Chaiyakunapruk N.
Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5556213/
Additional information of El Mondo:
Find more information/studies on calcium and colorectal cancer right here.
Colorectal adenomas can lead to colorectal cancer.