No Evidence for Posttreatment Effects of Vitamin D and Calcium Supplementation on Risk of Colorectal Adenomas in a Randomized Trial

Cancer Prev Res (Phila). 2019 May;12(5):295-304. doi: 10.1158/1940-6207.CAPR-19-0023. Epub 2019 Mar 4.


Vitamin D and calcium supplementation are postulated to have chemopreventive effects against colorectal neoplasia, yet in our previously reported randomized trial, there was no overall efficacy of calcium and/or vitamin D3 against colorectal adenoma recurrence. It is possible vitamin D3 and calcium chemopreventive effects are not detectable until beyond the 3- to 5-year follow-up captured in that trial. Accordingly, we explored possible vitamin D and calcium effects on posttreatment (observational) adenoma occurrence. In this secondary analysis of the observational follow-up phase of the Vitamin D/Calcium Polyp Prevention Study, participants who completed the treatment phase were invited to be followed for one additional surveillance colonoscopy cycle. We evaluated adenoma occurrence risk at surveillance colonoscopy, with a mean of 55 ± 15 months after treatment follow-up, according to randomized treatment with vitamin D versus no vitamin D, calcium versus no calcium, and calcium plus vitamin D versus calcium alone. Secondary outcomes included advanced and multiple adenomas. Among the 1,121 participants with observational follow-up, the relative risk (95% confidence interval, CI) of any adenoma was 1.04 (0.93-1.17) for vitamin D versus no vitamin D; 0.95 (0.84-1.08) for calcium versus no calcium; 1.07 (0.91-1.25) for calcium plus vitamin D versus calcium; and 0.96 (0.81-1.15) for calcium plus vitamin D versus neither. Risks of advanced or multiple adenomas also did not differ by treatment. Our results do not support an association between supplemental calcium and/or vitamin D3 for 3 to 5 years and risk of recurrent colorectal adenoma at an average of 4.6 years after treatment.

Publication types

  • Clinical Trial, Phase II
  • Clinical Trial, Phase III
  • Multicenter Study
  • Observational Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adenoma / diagnosis
  • Adenoma / epidemiology
  • Adenoma / prevention & control*
  • Adenoma / surgery
  • Aged
  • Calcium, Dietary / administration & dosage*
  • Colonoscopy
  • Colorectal Neoplasms / diagnosis
  • Colorectal Neoplasms / epidemiology
  • Colorectal Neoplasms / prevention & control*
  • Colorectal Neoplasms / surgery
  • Dietary Supplements
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Neoplasm Recurrence, Local / diagnosis
  • Neoplasm Recurrence, Local / epidemiology*
  • Neoplasm Recurrence, Local / prevention & control
  • Treatment Outcome
  • Vitamin D / administration & dosage*


  • Calcium, Dietary
  • Vitamin D