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Is Calcium Dangerous?

Friday, February 15, 2013

Beware! The press has jumped on a questionable newly published study with headlines that read, Research finding suggest that women with high intakes of calcium from dietary and supplementary sources are associated with twice the risk of death from heart disease when compared to those women with a lower intake.

This study is suggesting that calcium intake above 1,400 mg per day increases the risk of female cardiovascular morbidity. This study in question is based on data collected over a 20 year period from women enrolled in a Swedish study on mammograms.  We have problems with the study methodology. 

  • The study compares apples to oranges.  The data used to draw conclusions looked at diet and cancer, not whether calcium supplements were bad for the heart.  This fact alone is reason enough to question the study results. This study calcium data is based on dietary intake, which is always questionable since rarely do subjects accurately remember what they ate last Tuesday, or even yesterday for that matter.  The study does not identify the form of supplemental calcium the subjects were taking either.  Another red flag!

After giving this much thought, it seems reasonable to reintroduce our readers to an early 2012 Friday Pearl that was written by one of our esteemed scientific advisory board member biochemist, Dr. Steven Whiting. 

Dr. Whiting's Calcium Article:

A recent German study has, according to the drug driven press, indicated that taking calcium supplements places one at a greater risk for a heart attack! Once again the drug companies have the media in their pocket as this study has been published in virtually every publication and news broadcast worldwide. 

Every week there are studies showing the deadly dangers of pharmaceuticals but do you ever hear about these? Could all the hundreds of previous studies proving that calcium supplementation is not only safe but also essential be wrong? Let's take a closer look.

I have been in the nutrition and supplement field for almost 35 years, and I have seen this pattern over and over again. The Los Angeles Times as well as many papers in Europe have proclaimed, "Calcium supplements increase heart attacks". This is NOT exactly what the study said. So are calcium supplements safe? It depends on what form of calcium, the co-factors and how you take it. 

First of all, not all calcium supplements are the same. The majority of these products are simply ground up rock in the form of coral, dolomite, eggshell, etc. and are not only very difficult to absorb but also, due to their highly alkaline pH, potentially problematic. If you have followed our work with heart disease you know that cholesterol does not actually cause this problem.

The root cause is a condition called calcification of the arteries - where calcium builds up on the inside of certain spots on the artery due to free radical damage to the internal muscle wall. The most common form of calcium likely to contribute to this issue is alkaline calcium or that from cheap supplements. Calcium that has been pre-acidified through chelating with an acid is much less likely to remain circulating in the bloodstream for longer periods of time.

Absorption is the key to all nutrients, especially calcium. Essential co-factors must be present to facilitate calcium absorption to not only bone but to all areas where it is essential for life. The more of these co-factors present together with calcium the faster it will be absorbed to the tissues where it is needed.

The study concludes that perhaps taking calcium in higher one shot doses as in a supplement is a big part of the problem over getting calcium throughout the day as in food. There may be some logic in that, which is why we have always stressed to space out your calcium supplements throughout the day as only a limited amount of the mineral can be absorbed at one time. Whenever a study points to getting nutrients from food rather than supplements it's almost a guarantee that it was either funded or managed by pharmaceutical influenced interests such as our American Dietetic Association and similar organizations in Europe. Hundreds of studies have shown that the industrialized diet does not provide all the nutrients we need for optimal health, yet they keep singing that same tired song from the 1940's.

Let's see what some other studies have to say. May 2012, Journal of Clinical Nephrology: "Calcium and Vitamin D3 supplements proven effective in reducing bone loss in elderly women with kidney disease. Or how about: May 2012 Complementary Therapies in Clinical Practice: "Effects of polycystic ovary syndrome alleviated with vitamin D and calcium supplementation".

These are just two studies, both from this month alone, showing the benefits of calcium supplementation.

So are calcium supplements safe? Yes, absolutely providing that you take a Full Spectrum supplement with the right form of acidified calcium together with all the co-factors for enhanced uptake and absorption. A good calcium supplement should contain chelated calcium and magnesium. It should also contain the absorption co-factors Manganese, boron, copper, zinc and strontium for bone absorption. Lastly you should space your calcium supplements throughout the day and take them with meals. If you do so, proper calcium supplementation will continue to provide you with the many health benefits it always has and that have been shown by literally hundreds of studies over the last few decades."

Ellen Troyer, MT MA
Biosyntrx CEO / Chief Research Officer

Steven Whiting, PhD
Biosyntrx Scientific Advisory Board


It's disturbing to see so much press devoted to the study in question, given the vast number of well-designed published studies that suggest calcium supplementation supports bone health for most women, particularly those over the age of 50.  

It's also disturbing, given the 2012 FDA warning published inThe New England Journal of Medicine suggesting that doctors need to reassess which women are likely to benefit from popular bone-building drugs like Fosamax, Actonel and Reclast, given the lack of evidence showing that taking them for the long term really helps and the possibility that they put some women at risk for serious side effects.  Here is a video clip addressing the FDA warning featuring Dr. Clifford Rosen.  

Another disturbing issue, given the number of studies suggesting diets with higher calcium density (calcium per total calories) to be associated with a reduced incidence of overweight and obesity. Obesity is now considered an epidemic in our country.  

An important question for women to ask themselves: Have you given up calcium-rich dairy products because you think, or have been told by your doctor that you may be  lactose intolerant?  If so, think long and hard before giving up your calcium supplements based on the new study in question.  

Also remember that a number of studies suggest the risk of mortality for a one year period in hip fracture patients over the age of 65  to be three times higher than that in the general population.  The studies that address hip fracture mortality are below all the calcium studies. 


Calcium References - 

1.  Weaver CM, Heaney RP. Calcium. In: Shils M, Olson JA, Shike M, Ross AC, eds. Modern Nutrition in Health and Disease. 9th ed. Baltimore: Lippincott Williams & Wilkins; 1999:141-155.

2.  Heaney RP. Calcium, dairy products and osteoporosis. J Am Coll Nutr. 2000;19(2 Suppl):83S-99S.  (PubMed)

3.  Food and Nutrition Board, Institute of Medicine. Calcium. Dietary Reference Intakes: Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. Washington, D.C.: National Academy Press; 1997:71-145.  (National Academy Press)

4.  Brody T. Nutritional Biochemistry. 2nd ed. San Diego: Academic Press; 1999.

5.  Pearce SH, Thakker RV. The calcium-sensing receptor: insights into extracellular calcium homeostasis in health and disease. J Endocrinol. 1997;154(3):371-378.  (PubMed)

6.  Calvo MS. Dietary considerations to prevent loss of bone and renal function. Nutrition. 2000;16(7-8):564-566.  (PubMed)

7.  Devine A, Criddle RA, Dick IM, Kerr DA, Prince RL. A longitudinal study of the effect of sodium and calcium intakes on regional bone density in postmenopausal women. Am J Clin Nutr. 1995;62(4):740-745.  (PubMed)

8.  Carbone LD, Barrow KD, Bush AJ, et al. Effects of a low sodium diet on bone metabolism. J Bone Miner Metab. 2005;23(6):506-513.  (PubMed)

9.  Wigertz K, Palacios C, Jackman LA, et al. Racial differences in calcium retention in response to dietary salt in adolescent girls. Am J Clin Nutr. 2005;81(4):845-850.  (PubMed)

10.  Bonjour JP. Dietary protein: an essential nutrient for bone health. J Am Coll Nutr. 2005;24(6 Suppl):526S-536S.  (PubMed)

11.  Barger-Lux MJ, Heaney RP, Stegman MR. Effects of moderate caffeine intake on the calcium economy of premenopausal women. Am J Clin Nutr. 1990;52(4):722-725.  (PubMed)

12.  Harris SS, Dawson-Hughes B. Caffeine and bone loss in healthy postmenopausal women. Am J Clin Nutr. 1994;60(4):573-578.  (PubMed)

13.  Lloyd T, Johnson-Rollings N, Eggli DF, Kieselhorst K, Mauger EA, Cusatis DC. Bone status among postmenopausal women with different habitual caffeine intakes: a longitudinal investigation. J Am Coll Nutr. 2000;19(2):256-261.  (PubMed)

14.  Bostick R. Diet and nutrition in the prevention of colon cancer. In: Bendich A, Deckelbaum RJ, eds. Preventive Nutrition: The Comprehensive Guide for Health Professionals. 2nd ed. Totowa: Humana Press, Inc; 2001:57-95.

15.  Bonithon-Kopp C, Kronborg O, Giacosa A, Rath U, Faivre J. Calcium and fibre supplementation in prevention of colorectal adenoma recurrence: a randomised intervention trial. European Cancer Prevention Organisation Study Group. Lancet. 2000;356(9238):1300-1306.  (PubMed)

16.  Baron JA, Beach M, Mandel JS, et al. Calcium supplements and colorectal adenomas. Polyp Prevention Study Group. Ann N Y Acad Sci. 1999;889:138-145.  (PubMed)

17.  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(2):129-136.  (PubMed)

18.  Cho E, Smith-Warner SA, Spiegelman D, et al. Dairy foods, calcium, and colorectal cancer: a pooled analysis of 10 cohort studies. J Natl Cancer Inst. 2004;96(13):1015-1022.  (PubMed)

19.  Ma J, Giovannucci E, Pollak M, et al. Milk intake, circulating levels of insulin-like growth factor-I, and risk of colorectal cancer in men. J Natl Cancer Inst. 2001;93(17):1330-1336.  (PubMed)

20.  National Institutes of Health. Osteoporosis Prevention, Diagnosis, and Therapy. NIH Consensus Statement. 2000;17(1):1-36.

21.  Specker BL. Evidence for an interaction between calcium intake and physical activity on changes in bone mineral density. J Bone Miner Res. 1996;11(10):1539-1544.  (PubMed)

22.  Heller HJ. The role of calcium in the prevention of kidney stones. J Am Coll Nutr. 1999;18(5 Suppl):373S-378S.  (PubMed)

23.  Martini LA, Wood RJ. Should dietary calcium and protein be restricted in patients with nephrolithiasis? Nutr Rev. 2000;58(4):111-117.  (PubMed)

24.  Curhan GC, Willett WC, Rimm EB, Stampfer MJ. A prospective study of dietary calcium and other nutrients and the risk of symptomatic kidney stones. N Engl J Med. 1993;328(12):833-838.  (PubMed)

25.  Curhan GC, Willett WC, Speizer FE, Spiegelman D, Stampfer MJ. Comparison of dietary calcium with supplemental calcium and other nutrients as factors affecting the risk for kidney stones in women. Ann Intern Med. 1997;126(7):497-504.  (PubMed)

26.  Taylor EN, Stampfer MJ, Curhan GC. Dietary factors and the risk of incident kidney stones in men: new insights after 14 years of follow-up. J Am Soc Nephrol. 2004;15(12):3225-3232.  (PubMed)

27.  Curhan GC, Willett WC, Knight EL, Stampfer MJ. Dietary factors and the risk of incident kidney stones in younger women: Nurses' Health Study II. Arch Intern Med. 2004;164(8):885-891.  (PubMed)

28.  Liebman M, Chai W. Effect of dietary calcium on urinary oxalate excretion after oxalate loads. Am J Clin Nutr. 1997;65(5):1453-1459.  (PubMed)

29.  Burtis WJ, Gay L, Insogna KL, Ellison A, Broadus AE. Dietary hypercalciuria in patients with calcium oxalate kidney stones. Am J Clin Nutr. 1994;60(3):424-429.  (PubMed)

30.  Martini LA, Cuppari L, Colugnati FA, et al. High sodium chloride intake is associated with low bone density in calcium stone-forming patients. Clin Nephrol. 2000;54(2):85-93.  (PubMed)

31.  Jackson RD, LaCroix AZ, Gass M, et al. Calcium plus vitamin D supplementation and the risk of fractures. N Engl J Med. 2006;354(7):669-683.  (PubMed)

32.  Ritchie LD, King JC. Dietary calcium and pregnancy-induced hypertension: is there a relation? Am J Clin Nutr. 2000;71(5 Suppl):1371S-1374S.  (PubMed)

33.  Kulier R, de Onis M, Gulmezoglu AM, Villar J. Nutritional interventions for the prevention of maternal morbidity. Int J Gynaecol Obstet. 1998;63(3):231-246.  (PubMed)

34.  Levine RJ, Hauth JC, Curet LB, et al. Trial of calcium to prevent preeclampsia. N Engl J Med. 1997;337(2):69-76.  (PubMed)

35.  Bruening K, Kemp FW, Simone N, Holding Y, Louria DB, Bogden JD. Dietary calcium intakes of urban children at risk of lead poisoning. Environ Health Perspect. 1999;107(6):431-435.  (PubMed)

36.  Hertz-Picciotto I, Schramm M, Watt-Morse M, Chantala K, Anderson J, Osterloh J. Patterns and determinants of blood lead during pregnancy. Am J Epidemiol. 2000;152(9):829-837.  (PubMed)

37.  Muldoon SB, Cauley JA, Kuller LH, Scott J, Rohay J. Lifestyle and sociodemographic factors as determinants of blood lead levels in elderly women. Am J Epidemiol. 1994;139(6):599-608.  (PubMed)

38.  Birkett NJ. Comments on a meta-analysis of the relation between dietary calcium intake and blood pressure. Am J Epidemiol. 1998;148(3):223-228; discussion 232-223.  (PubMed)

39.  Griffith LE, Guyatt GH, Cook RJ, Bucher HC, Cook DJ. The influence of dietary and nondietary calcium supplementation on blood pressure: an updated metaanalysis of randomized controlled trials. Am J Hypertens. 1999;12(1 Pt 1):84-92.  (PubMed)

40.  Appel LJ, Moore TJ, Obarzanek E, et al. A clinical trial of the effects of dietary patterns on blood pressure. DASH Collaborative Research Group. N Engl J Med. 1997;336(16):1117-1124.  (PubMed)

41.  Conlin PR, Chow D, Miller ER, 3rd, et al. The effect of dietary patterns on blood pressure control in hypertensive patients: results from the Dietary Approaches to Stop Hypertension (DASH) trial. Am J Hypertens. 2000;13(9):949-955.  (PubMed)

42.  Miller GD, DiRienzo DD, Reusser ME, McCarron DA. Benefits of dairy product consumption on blood pressure in humans: a summary of the biomedical literature. J Am Coll Nutr. 2000;19(2 Suppl):147S-164S.  (PubMed)

43.  Brown JE. Preconception Nutrition: Conditions and Interventions. In: Brown JE, ed. Nutrition through the Life Cycle. Belmont: Wadsworth/Thomson Learning; 2002:53-60.

44.  Bendich A. The potential for dietary supplements to reduce premenstrual syndrome (PMS) symptoms. J Am Coll Nutr. 2000;19(1):3-12.  (PubMed)

45.  Thys-Jacobs S, Starkey P, Bernstein D, Tian J. Calcium carbonate and the premenstrual syndrome: effects on premenstrual and menstrual symptoms. Premenstrual Syndrome Study Group. Am J Obstet Gynecol. 1998;179(2):444-452.  (PubMed)

46.  Thys-Jacobs S, Ceccarelli S, Bierman A, Weisman H, Cohen MA, Alvir J. Calcium supplementation in premenstrual syndrome: a randomized crossover trial. J Gen Intern Med. 1989;4(3):183-189.  (PubMed)

47.  Alvir JM, Thys-Jacobs S. Premenstrual and menstrual symptom clusters and response to calcium treatment. Psychopharmacol Bull. 1991;27(2):145-148.  (PubMed)

48.  Bertone-Johnson ER, Hankinson SE, Bendich A, Johnson SR, Willett WC, Manson JE. Calcium and vitamin D intake and risk of incident premenstrual syndrome. Arch Intern Med. 2005;165(11):1246-1252.  (PubMed)

49.  Weaver CM, Proulx WR, Heaney R. Choices for achieving adequate dietary calcium with a vegetarian diet. Am J Clin Nutr. 1999;70(3 Suppl):543S-548S.  (PubMed)

50.  Hendler SS, Rorvik DR, eds. PDR for Nutritional Supplements. Montvale: Medical Economics Company, Inc; 2001.

51.  Bourgoin BP, Evans DR, Cornett JR, Lingard SM, Quattrone AJ. Lead content in 70 brands of dietary calcium supplements. Am J Public Health. 1993;83(8):1155-1160.  (PubMed)

52.  Ross EA, Szabo NJ, Tebbett IR. Lead content of calcium supplements. JAMA. 2000;284(11):1425-1429.  (PubMed)

53.  Giovannucci E, Rimm EB, Wolk A, et al. Calcium and fructose intake in relation to risk of prostate cancer. Cancer Res. 1998;58(3):442-447. (PubMed)

54.  Chan JM, Giovannucci E, Andersson SO, Yuen J, Adami HO, Wolk A. Dairy products, calcium, phosphorous, vitamin D, and risk of prostate cancer (Sweden). Cancer Causes Control. 1998;9(6):559-566.  (PubMed)

55.  Chan JM, Stampfer MJ, Ma J, Gann PH, Gaziano JM, Giovannucci EL. Dairy products, calcium, and prostate cancer risk in the Physicians' Health Study. Am J Clin Nutr. 2001;74(4):549-554.  (PubMed)

56.  Mitrou PN, Albanes D, Weinstein SJ, et al. A prospective study of dietary calcium, dairy products and prostate cancer risk (Finland). Int J Cancer. 2007;120(11):2466-2473.  (PubMed)

57.  Chan JM, Giovannucci EL. Dairy products, calcium, and vitamin D and risk of prostate cancer. Epidemiol Rev. 2001;23(1):87-92.

58.  Vlajinac HD, Marinkovic JM, Ilic MD, Kocev NI. Diet and prostate cancer: a case-control study. Eur J Cancer. 1997;33(1):101-107.  (PubMed)

59.  Gao X, LaValley MP, Tucker KL. Prospective studies of dairy product and calcium intakes and prostate cancer risk: a meta-analysis. J Natl Cancer Inst. 2005;97(23):1768-1777.  (PubMed)

60.  Severi G, English DR, Hopper JL, Giles GG. Re: Prospective studies of dairy product and calcium intakes and prostate cancer risk: a meta-analysis. J Natl Cancer Inst. 2006;98(11):794-795; author reply 795.

61.  Vella A, Gerber TC, Hayes DL, Reeder GS. Digoxin, hypercalcaemia, and cardiac conduction. Postgrad Med J. 1999;75(887):554-556.  (PubMed)

62.  Moser LR, Smythe MA, Tisdale JE. The use of calcium salts in the prevention and management of verapamil-induced hypotension. Ann Pharmacother. 2000;34(5):622-629.  (PubMed)

63.  Bania TC, Blaufeux B, Hughes S, Almond GL, Homel P. Calcium and digoxin vs. calcium alone for severe verapamil toxicity. Acad Emerg Med. 2000;7(10):1089-1096.  (PubMed)

64.  Minerals. Drug Facts and Comparisons. St. Louis: Facts and Comparisons; 2000:27-51.

65.  Wood RJ, Zheng JJ. High dietary calcium intakes reduce zinc absorption and balance in humans. Am J Clin Nutr. 1997;65(6):1803-1809.  (PubMed)

66.  Zemel MB, Shi H, Greer B, Dirienzo D, Zemel PC. Regulation of adiposity by dietary calcium. FASEB J. 2000;14(9):1132-1138.  (PubMed)

67.  Lin YC, Lyle RM, McCabe LD, McCabe GP, Weaver CM, Teegarden D. Dairy calcium is related to changes in body composition during a two-year exercise intervention in young women. J Am Coll Nutr. 2000;19(6):754-760.  (PubMed)

68.  Davies KM, Heaney RP, Recker RR, Lappe JM, Barger-Lux MJ, Rafferty K, Hinders S. Calcium intake and body weight. J Clin Endocrinol Metabol. 2000;85(12):4635-4638.  (PubMed)

69.  Gunther CW, Legowski PA, Lyle RM, et al. Dairy products do not lead to alterations in body weight or fat mass in young women in a 1-y intervention. Am J Clin Nutr. 2005;81(4):751-756.  (PubMed)

70.  Eagan MS, Lyle RM, Gunther CW, Peacock M, Teegarden D. Effect of 1-year dairy product intervention on fat mass in young women: 6-month follow-up. Obesity (Silver Spring). 2006;14(12):2242-2248.  (PubMed)

References Addressing Hip and Other Fracture Mortality in the Elderly

  1. Vestergaard P, Rejnmark L, Mosekilde L: Increased mortality in patients with a hip fracture-effect of pre-morbid conditions and post-fracture complications.

    Osteoporos Int 2007, 18:1583-1593. PubMed Abstract | Publisher Full Text OpenURL

  2. Roche JJ, Wenn RT, Sahota O, Moran CG: Effect of comorbidities and postoperative complications on mortality after hip fracture in elderly people: prospective observational cohort study.

    BMJ 2005, 331:1374. PubMed Abstract | Publisher Full Text | PubMed Central Full Text OpenURL

  3. Clayer MT, Bauze RJ: Morbidity and mortality following fractures of the femoral neck and trochanteric region: analysis of risk factors.

    J Trauma 1989, 29:1673-1678. PubMed Abstract | Publisher Full Text OpenURL

  4. Abrahamsen B, van Staa T, Ariely R, Olson M, Cooper C: Excess mortality following hip fracture: a systematic epidemiological review.

    Osteoporos Int 2009, 20:1633-1650. PubMed Abstract | Publisher Full Text OpenURL

  5. Handoll HH, Farrar MJ, McBirnie J, Tytherleigh-Strong G, Milne AA, Gillespie WJ: Heparin, low molecular weight heparin and physical methods for preventing deep vein thrombosis and pulmonary embolism following surgery for hip fractures.

    Cochrane Database Syst Rev 2002, CD000305. OpenURL

  6. Wehren LE, Hawkes WG, Orwig DL, Hebel JR, Zimmerman SI, Magaziner J: Gender differences in mortality after hip fracture: the role of infection.

    J Bone Miner Res 2003, 18:2231-2237. PubMed Abstract | Publisher Full Text OpenURL

  7. Browner WS, Pressman AR, Nevitt MC, Cummings SR: Mortality following fractures in older women. The study of osteoporotic fractures.

    Arch Int Med 1996, 156:1521-1525. Publisher Full Text OpenURL

  8. Deakin DE, Boulton C, Moran CG: Mortality and causes of death among patients with isolated limb and pelvic fractures.

    Injury 2007, 38:312-317. PubMed Abstract | Publisher Full Text OpenURL

  9. Manderbacka KKS, Arffman M, Keskimäki I: Regional differences in mortality amenable to health care 1992-2003 (English summary).

  10. Suomen Lääkärilehti 2009, 64:6. PubMed Abstract | Publisher Full Text OpenURL

  11. Piirtola M, Vahlberg T, Lopponen M, Raiha I, Isoaho R, Kivela SL: Fractures as predictors of excess mortality in the aged-a population-based study with a 12-year follow-up.

    Eur J Epidemiol 2008, 23:747-755. PubMed Abstract | Publisher Full Text OpenURL