Does Supplementing with Vitamin D, Calcium Cut Colon Cancer Risk?
(HealthDay News) — Supplemental vitamin D and calcium do not seem to reduce the risk of recurrent colorectal adenomas, according to a study published online October 14 in the New England Journal of Medicine.
John A. Baron, MD, from Dartmouth University in Hanover, NH, and colleagues randomly assigned 2,259 patients with recently diagnosed adenomas to receive daily vitamin D3 (1,000 IU), calcium as carbonate (1,200mg), both, or neither. Follow-up colonoscopy was expected to be performed three or five years after the baseline examinations.
The researchers found that participants who received vitamin D had a mean net increase in serum 25-hydroxyvitamin D levels of 7.83ng per milliliter compared with participants given placebo. During follow-up, 43% of participants had one or more adenomas diagnosed. The adjusted risk ratios for recurrent adenomas were 0.99 (95% confidence interval [CI], 0.89–1.09) for those taking vitamin D vs. no vitamin D, 0.95 (95% CI, 0.85–1.06) for calcium vs. no calcium, and 0.93 (95% CI, 0.8–1.08) for both agents vs. neither agent.
"Daily supplementation with vitamin D3 (1,000 IU), calcium (1,200mg), or both after removal of colorectal adenomas did not significantly reduce the risk of recurrent colorectal adenomas over a period of 3–5 years," conclude the authors.