Calcium

CautionSuggested

3 studies · 2 recommendations

Last updated: February 21, 2026

Caution1 studies

High calcium intake may increase advanced prostate cancer risk

The systematic review identified high calcium intake as one of three dietary factors consistently associated with increased risk for advanced prostate cancer. Men concerned about prostate cancer risk should be cautious about excessive calcium supplementation while maintaining adequate intake for bone health.

Evidence

Dietary factors and risk for advanced prostate cancer

Authors: Gathirua-Mwangi, Wambui G., Zhang, Jianjun

Published: March 1, 2014

A systematic review evaluating 46 eligible papers from PubMed through September 2012 found that high calcium intake is associated with increased risk for advanced prostate cancer. Calcium was identified as one of three dietary factors — along with saturated fat and well-done meats — that showed overall consistent associations with elevated advanced prostate cancer risk across epidemiologic studies. Case-control studies generally supported a significant effect, while cohort studies produced mixed but supportive findings regarding calcium and advanced disease risk.

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Suggested2 studies

Calcium supplementation may reduce prostate cancer risk and supports bone health during treatment

A meta-analysis of randomized controlled trials (3 trials, n=1,806) found calcium supplements (≥500 mg/d) reduced prostate cancer risk by 46% (RR 0.54, 95% CI 0.30–0.96, P=0.03). Patient-level data from 2 trials (n=1,134) showed a consistent but non-significant trend (HR 0.61, 95% CI 0.30–1.23). A separate RCT (RTOG 0518, n=96) mandated calcium and vitamin D as standard care for prostate cancer patients on hormone therapy, where the observation arm experienced significant bone mineral density losses of 5–8% at key skeletal sites over 36 months. Across both studies (combined n≈1,902), calcium supplementation at ≥500 mg/d demonstrated a dual role: potential cancer risk reduction and essential bone health maintenance during androgen deprivation therapy.

Evidence

RTOG 0518: Randomized Phase III Trial to Evaluate Zoledronic Acid for Prevention of Osteoporosis and Associated Fractures in Prostate Cancer Patients

Authors: Gore, Elizabeth, Kachnic, Lisa A., Kim, Harold E., Lawton, Colleen AF, Martin, Andre-Guy, Nabid, Abdenour, Pugh, Stephanie L, Shah, Amit B., Smith, Matthew, Tai, Patricia

Published: July 7, 2014

RTOG 0518 randomized 96 eligible patients with advanced non-metastatic prostate cancer on LHRH agonist therapy and radiotherapy. All patients in both arms received calcium and Vitamin D supplementation as standard care. At 36 months median follow-up, the observation arm (calcium and Vitamin D only) showed BMD percent changes of −5% at lumbar spine (p<0.0001 compared to zoledronic acid arm at +6%), −8% at left total hip (p=0.0002 vs. +1%), and −8% at left femoral neck (p=0.0007 vs. +3%). Only 2 fractures occurred across all 96 patients (1 per arm, p=0.95). Calcium supplementation was mandated for all trial participants as essential baseline bone health support.

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Calcium supplements and cancer risk : a meta-analysis of randomised controlled trials

Authors: Avenell, Alison, Bolland, Mark J, Bristow, Sarah M, Gamble, Greg D, Grey, Andrew, Maclennan, Graeme S, Reid, Ian R

Published: April 19, 2013

A meta-analysis of 10 randomised placebo-controlled trials (n=10,496, mean duration 3.9 years) examined calcium supplements (≥500 mg/d) without co-administered vitamin D on cancer risk. For prostate cancer, data from 3 trials (n=1,806) showed allocation to calcium significantly reduced prostate cancer risk (relative risk 0.54, 95% CI 0.30–0.96, P=0.03). Patient-level data from 2 trials (n=1,134) showed a consistent but non-significant trend (hazard ratio 0.61, 95% CI 0.30–1.23, P=0.16). The effect was noted with few total events, limiting statistical power for definitive conclusions.

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