Vitamin D Supplementation: Does It Have a Preventative or Therapeutic Role in Cancer?

Abstract

Although best known for its role in skeletal health, a deficiency of vitamin D has also been implicated in cancer formation and progression. The aim of this article was to review the relationship between circulating levels of vitamin D {25(OH)D} and both the risk of developing cancer and outcome from cancer. We also reviewed the effects of vitamin D supplementation on cancer risk and outcome. Our primary focus was on patients with colorectal and breast cancer, as these are two of the cancer types best investigated with respect to the effects of vitamin D on cancer risk and outcome. Based on our review of the literature, we conclude that although low circulating levels of 25(OH)D appears to be associated with an increased risk of developing breast and colorectal cancer, the available evidence suggests that supplementation of healthy subjects with vitamin D does not decrease cancer risk. Supplementation may however, improve outcomes in patients who develop cancer, but this finding remains to be confirmed in an appropriately powered randomized clinical trial.

Authors’ Contributions

MJD reviewed the literature and wrote the first draft. MM, KB and JC edited the manuscript. All authors agreed with the final version of the manuscript.

Institutional Review Board Statement

As this was a literature based study, institutional board review was not required.

Conflict of Interest Statement

JC conflict of interests; Research funding (to institution): Eisai, Puma Biotechnology, Roche, Boehringer Ingelheim; Employment: OncoMark, Ltd.; Honoraria: Eisai, Puma Biotechnology; MSD Oncology, Pfizer, G1 Therapeutics; Novartis; Speaker’s Bureau: Boehringer Ingelheim, Genomic Health, Roche, Pfizer; Shares: OncoMark Ltd; Travel and accommodation expenses: Pfizer, MSD, Abbvie, Astrazeneca, Novartis. MJD, MM, KB have no conflict of interests.

Correction statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

We thank the Cancer Clinical Research Trust for funding this work. Our funding sponsors had no input to the choice of this research project; design of the study; in the collection, analyses or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.