Is Your Calcium Supplement Killing You

author avatar Dr. Eric Berg 08/31/2023

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Here are some articles and studies that talk about the relationship between calcium and bone, heart, arteries, and much more.

Calcium Does Not Do Much for Bones

Grant AM, Avenell A, Campbell MK, McDonald AM, MacLennan GS, McPherson GC, Anderson FH, Cooper C, Francis RM, Donaldson C, Gillespie WJ, Robinson CM, Torgerson DJ, Wallace WA; RECORD Trial Group. "Oral vitamin D3 and calcium for secondary prevention of low-trauma fractures in elderly people (Randomised Evaluation of Calcium Or vitamin D, RECORD): a randomised placebo-controlled trial." Lancet. 2005 May 7-13;365(9471):1621-8.

Tang BM, Eslick GD, Nowson C, Smith C, Bensoussan A. "Use of calcium or calcium in combination with vitamin D supplementation to prevent fractures and bone loss in people aged 50 years and older: a meta-analysis." Lancet. 2007 Aug 25;370(9588):657-66.

Calcium Increase Heart Attacks

Abstract Title:

Calcium supplements with or without vitamin D and risk of cardiovascular events: reanalysis of the Women's Health Initiative limited access dataset and meta-analysis.

Abstract Source:

BMJ. 2011;342:d2040. Epub 2011 Apr 19. PMID: 21505219

Abstract Author(s):

Mark J Bolland, Andrew Grey, Alison Avenell, Greg D Gamble, Ian R Reid

Article Affiliation:

Department of Medicine, University of Auckland, Private Bag 92 019, Auckland 1142, New Zealand.


OBJECTIVES: To investigate the effects of personal calcium supplement used on cardiovascular risk in the Women's Health Initiative Calcium/Vitamin D Supplementation Study (WHI CaD Study), using the WHI dataset, and to update the recent meta-analysis of calcium supplements and cardiovascular risk.

DESIGN: Reanalysis of WHI CaD Study limited access dataset and incorporation in meta-analysis with eight other studies. Data source WHI CaD Study, a seven year, randomised, placebo controlled trial of calcium and vitamin D (1g calcium and 400 IU vitamin D daily) in 36,282 community dwelling postmenopausal women. Main outcome measures Incidence of four cardiovascular events and their combinations (myocardial infarction, coronary revascularisation, death from coronary heart disease, and stroke) assessed with patient-level data and trial-level data.

RESULTS: In the WHI CaD Study, there was an interaction between personal use of calcium supplements and allocated calcium and vitamin D for cardiovascular events. In the 16,718 women (46%) who were not taking personal calcium supplements at randomisation, the hazard ratios for cardiovascular events with calcium and vitamin D ranged from 1.13 to 1.22 (P = 0.05 for clinical myocardial infarction or stroke, P = 0.04 for clinical myocardial infarction or revascularisation), whereas in the women taking personal calcium supplements, cardiovascular risk did not alter with allocation to calcium and vitamin D. In meta-analyses of three placebo controlled trials, calcium and vitamin D increased the risk of myocardial infarction (relative risk 1.21 (95% confidence interval 1.01 to 1.44), P = 0.04), stroke (1.20 (1.00 to 1.43), P = 0.05), and the composite of myocardial infarction or stroke (1.16 (1.02 to 1.32), P = 0.02). In meta-analyses of placebo controlled trials of calcium or calcium and vitamin D, complete trial-level data were available for 28,072 participants from eight trials of calcium supplements and the WHI CaD participants not taking personal calcium supplements. In total, 1384 individuals had an incident myocardial infarction or stroke. Calcium or calcium and vitamin D increased the risk of myocardial infarction (relative risk 1.24 (1.07 to 1.45), P = 0.004) and the composite of myocardial infarction or stroke (1.15 (1.03 to 1.27), P = 0.009).

CONCLUSIONS: Calcium supplements with or without vitamin D modestly increase the risk of cardiovascular events, especially myocardial infarction, a finding obscured in the WHI CaD Study by the widespread use of personal calcium supplements. A reassessment of the role of calcium supplements in osteoporosis management is warranted.

Calcium Increasing Urinary Tract Infections

Abstract Title:

Increased risk of urinary tract infection associated with the use of calcium supplements.

Abstract Source:

Urol Res. 1990;18(3):213-7. PMID: 2204174

Abstract Author(s):

L L Apicella, A E Sobota

Article Affiliation:

Department of Biological Sciences, Youngstown State University, Ohio.


Since ions are known to influence the interaction between cells, we undertook an examination of the effect of various ions on bacterial adherence to uroepithelial cells. While most of the ions examined had no effect or decreased bacterial adherence, calcium ions significantly increased bacterial adherence. It was demonstrated, in vitro that as the concentration of calcium was increased to levels higher than normally found in the urine, there was a significant increase in bacterial adherence. It was also found that if the diet was supplemented with calcium there was an increase in the excretion of calcium in the urine and a corresponding increase in bacterial adherence when bacteria and uroepithelial cells were incubated in this urine. It is suggested that an excretion of excess calcium in the urine may lead to an increased bacterial adherence in vivo and an increased potential for urinary tract infections.

Article Published Date : Jan 01, 1990

Study Type : Meta Analysis

Additional Links

Diseases : Urinary Tract Infections : CK(338) : AC(47)

Problem Substances : Calcium Carbonate : CK(176) : AC(19)

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