Some studies suggest that high calcium intake may be associated with the development of prostate cancer, with the underlying hypothesis that calcium suppresses the formation of vitamin D.
An analysis of the Health Professionals Follow-Up Study found a significant association between high calcium intake and prostate cancer (multivariate RR, 2.97; 95% CI, 1.61-5.50) and metastatic prostate cancer (RR, 4.57; 95% CI, 1.88-11.1).9 This finding was replicated by a case-control study of a 1062 men in Sweden, in which high calcium intake increased the risk of prostate cancer (RR, 1.91; 95% CI, 1.23-2.97) and metastatic prostate cancer (RR, 2.64; 95% CI, 1.24-5.61).10
These findings were further supported by a large, prospective cohort of 65,321 elderly men from the US.11 Men completed a diet and lifestyle questionnaire, and prostate cancer was documented during follow-up. Total calcium intake from dietary and supplemental sources was significantly associated with an increased risk of prostate cancer (RR, 1.2; 95% CI, 1.0-1.6).
A randomized, controlled trial, however, did not find an association between calcium intake and prostate cancer risk.12 This study randomly assigned 672 men to receive calcium carbonate (3 g, or 1200 mg elemental calcium) or placebo daily for 4 years. Subjects were followed for a total of 12 years, and reports of prostate cancer were confirmed by medical record review.
There was no significant difference in prostate cancer after a mean follow-up of 10.3 years in the calcium and placebo groups (unadjusted RR, 0.83; 95% CI, 0.52-1.32). But after 2 years post-treatment (6 years total), there were significantly fewer prostate cancer diagnoses among men supplemented with calcium compared with placebo (unadjusted RR, 0.52; 95% CI, 0.28-0.98).
In addition, a study of 9559 subjects from the Prostate Cancer Prevention Trial found no consistent association between calcium supplementation and prostate cancer risk.13 This study found a significant protective effect of high dietary calcium intake against high-grade prostate cancer (OR, 0.43; 95% CI, 0.21-0.89), but an association with low-grade tumors (OR, 1.27; 95% CI, 1.02-1.57).
The evidence regarding the effect of calcium supplementation on colorectal adenoma recurrence is mixed, with some randomized controlled trials demonstrating a protective effect, whereas others showed no association, though calcium may decrease the risk of colorectal cancer recurrence.
Though calcium supplementation was associated with increased risk of prostate and metastatic prostate cancer in epidemiologic studies, these findings were not confirmed in a randomized, controlled trial. High calcium intake or supplementation is therefore unlikely to cause prostate cancer.
- Calcium: fact sheet for health professionals. National Institutes of Health website. https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/. Updated November 17, 2016. Accessed August 14, 2017.
- Baron JA, Beach M, Mandel JS, et al. Calcium supplements for the prevention of colorectal adenomas. N Engl J Med. 1999;340:101-7.
- Wallace K, Baron JA, Cole BF, et al. Effect of calcium supplementation on the risk of large bowel polyps. J Natl Cancer Inst. 2004;96:921-5.
- Grau MV, Baron JA, Sandler RS, et al. Prolonged effect of calcium supplementation on risk of colorectal adenomas in a randomized trial. J Natl Cancer Inst. 2007;99:129-36. doi: 10.1093/jnci/djk016
- Bonithon-Kopp C, Kronborg O, Giacosa A, Rath U, Faivre J. Calcium and fibre supplementation in prevention of colorectal adenoma recurrence: a randomized intervention trial. European Cancer Prevention Organisation Study Group. Lancet. 2000;356:1300-6.
- Baron JA, Barry EL, Mott LA, et al. A trial of calcium and vitamin D for the prevention of colorectal adenomas. N Engl J Med. 2015;373:1519-30.
- Dai Q, Sandler RS, Barry EL, Summers R, Grau M, Baron J. Calcium, magnesium, and colorectal cancer. Epidemiology. 2012;23:504-5. doi: 10.1097/EDE.0b013e31824deb09
- Chu DZ, Hussey MA, Alberts DS, et al. Colorectal chemoprevention pilot study (SWOG-9041), randomized and placebo-controlled: the importance of multiple luminal lesions. Clin Colorectal Cancer. 2011;10:310-6. doi: 10.1016/j.clcc.2011.06.005
- Giovannucci E, Rimm EB, Wolk A, et al. Calcium and fructose intake in relation to risk of prostate cancer. Cancer Res. 1998;58:442-7.
- Chan JM, Giovannucci E, Andersson SO, Yen J, Adami HO, Wolk A. Dairy products, calcium, phosphorus, vitamin D, and risk of prostate cancer (Sweden). Cancer Causes Control. 1998;9:559-66.
- Rodriguez C, McCullough ML, Mondul AM, et al. Calcium, dairy products, and risk of prostate cancer in a prospective cohort of United States men. Cancer Epidemiol Biomarkers Prev. 2003;12:597-603.
- Baron JA, Beach M, Wallace K, et al. Risk of prostate cancer in a randomized clinical trial of calcium supplementation. Cancer Epidemiol Biomarkers Prev. 2005;14:586-9.
- Kristal AR, Arnold KB, Neuhouser ML, et al. Diet, supplement use, and prostate cancer risk: results from the Prostate Cancer Prevention Trial. Am J Epidemiol. 2010;172:566-77. doi: 10.1093/aje/kwq148