Calcium Supplements Do Not Cause Heart Disease

I was very skeptical of the studies that seemed to show that taking calcium supplements or consuming calcium would lead to calcium buildup in the arteries and contribute to heart disease. Calcium is an essential mineral in the body that is essential in cellular metabolism as a signaling molecule and important for the strength of our teeth and bones, and most Americans are lacking adequate levels. I discussed this in a video recorded 3 years ago. watch video here But at the time, several studies were published that seemed to show that excessive calcium intake, esp. from supplements, would get deposited in the arteries and contributed to atherosclerosis and heart disease.(1,2,3,4) This led many doctors to stop recommending calcium supplements. I think this was a great disservice to many patients who needlessly lost bone mass because of this advice. Let’s not forget the significance of osteoporosis and osteopenia in the US. Over 54 million Americans suffer with bone loss and one in two women and one in four men over the age of 50 will break a bone related to osteoporosis, according to The National Osteoporosis Foundation. The US spends 19 billion dollars per year for health care costs related to such fractures.

There is no physiological reason why simply having more calcium would lead to it getting deposited in the arteries. It is oxidized lipids in the presence of inflammation in the arterial walls that results in plaque formation. There is always sufficient calcium in the blood stream to form plaques and increasing the amount of calcium is unlikely to play any role in this process. Granted, there are negative effects of overconsuming poorly absorbable forms of calcium, such as the calcium carbonate found in Tums, resulting in Milk Alkali Syndrome (5) Equally important is that the patient consume optimal levels of magnesium, vitamin D3, and vitamin K, preferably MK7, to facilitate the utilization of the calcium and bone formation. Further, in patients with normal kidney function, the body is able to excrete a reasonable amount of excess calcium fairly easily without consequence.

Recently a review and meta-analysis published in the Annals of Internal Medicine concluded that “Calcium intake within tolerable upper intake levels (2000 to 2500 mg/d) is not associated with CVD risk in generally healthy adults.” In fact, with the highest calcium intake (greater than or equal to 1453 mg daily) compared to the lowest intake (less than 434 mg), there was a 27% decreased risk of coronary artery calcium, that is, in the amount of atherosclerotic plaque formation in their arteries. This led the American Society for Preventative Cardiology and the National Osteoporosis Foundation to conclude that calcium supplements in dosages up to 2500 mg/day do not increase the risk of heart attacks, strokes or cardiovascular disease.(6,7) The authors of this paper did separate out the supplement users from the calcium from food and did see some increase CVD from supplements but not from food. However, this was with smaller supplement amounts and not with larger amounts of supplements, which really doesn’t make any sense. And once again, those subjects who had the largest intake of calcium from a combination of food and supplements had a lower risk, so it is hard to understand how taking supplements, unless they were of very poor quality, could pose any risk. My conclusion from this and the other studies is that reasonable amounts of quality calcium supplements are safe and do not contribute to heart disease. To make sure the calcium is utilized by the body for bone formation and its other functions, make sure to take a quality form like calcium citrate, malate, or hydroxyapatite, and take it with magnesium, vitamin C, vitamin D3, and vitamin K2-MK7 and keep your total intake from both food and supplements under 2500 mg/day.

References:
1. Bolland MJ, Avenell A, et al.. Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis. BMJ. 2010;341:c3691.
2. Bolland MJ, Grey A, Avenell A, Gamble GD, Reid IR. 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. BMJ. 2011;342:d2040.
3. Reid IR, Bristow SM, Bolland MJ. Cardiovascular complications of calcium supplements. J Cell Biochem. 2015;116:494–501.
4. Xiao Q, Murphy RA, Houston DK, et al. Dietary calcium and supplemental calcium intak and cardiovascular disease mortality: The National Institutes of Health—AARP diet and health study. JAMA Intern Med. 2013;173(8):639-46.
5. Felsenfeld AJ, Levine BS. Milk alkalai syndrome and the dynamics of calcium homeostasis. Clin J Am Soc Nephrol; 2006. 1(4):641-54.
6. Chung M, Tang AM, Fu Z, Wang DD, Newberry SJ. Calcium Intake and Cardiovascular Disease Risk: An Updated Systematic Review and Meta-analysis. Ann Intern Med. [Epub ahead of print 25 October 2016] doi: 10.7326/M16-1165
7. Kopecky SL, Bauer DC, Gulati M, et al. Lack of evidence linking calcium with or without vitamin D supplementation to cardiovascular disease in generally healthy adults: A clinical guideline from the National Osteoporosis Foundation and the American Society for Preventive Cardiology. Ann Intern Med. [Epub ahead of print 25 October 2016] doi: 10.7326/M16-1743
8. Nutrition Action Newsletter, December 2016.