Vitamin D supplements did not significantly reduce cancer risk in trial of older women

Of 2,303 women with high vitamin D levels, 45 women taking vitamin D3 and calcium supplements were diagnosed with cancer within four years, compared with 64 women taking placebo.

Calcium tablet supplements

The role of vitamin D in preventing cancer is a growing area of interest. A number of studies have shown an inverse relationship between cancer risk and sunlight exposure.

A randomised clinical trial was conducted to measure the effect of vitamin D3 and calcium supplements on the risk of all-type cancer in 2,303 healthy, postmenopausal women whose blood levels of vitamin D were already above the current recommended level.

In total, 1,156 women were allocated to the treatment group, while 1,147 were allocated to placebo.

After four years of follow-up, the researchers noted that a new diagnosis of cancer had been made in 45 women in the treatment group and 64 women who were given placebo.

Reporting in the Journal of the American Medical Association
[1]
(online, 28 March 2017), the researchers conclude that although supplementation decreased the incidence of cancer by 30%, the effect was not statistically significant. They say further research is needed to confirm the role of vitamin D in cancer prevention.

References

[1] Lappe J, Watson P, Travers-Gustafson D et al. Effect of vitamin D and calcium supplementation on cancer incidence in older women: a randomized clinical trial. JAMA 2017;317(12):1234-1243. doi: 10.1001/jama.2017.2115

Last updated
Citation
The Pharmaceutical Journal, April 2017;Online:DOI:10.1211/PJ.2017.20202540