Two of the most frequently asked questions I field from patients:
#1) Are there safety issues with supplemental calcium...and specifically...is there an increased risk for heart disease from taking calcium in a pill form? And,
#2) Do calcium supplements cause kidney stones?
My response to both is, "no". Calcium supplements ARE safe and especially if you make sure your body has enough magnesium, and vitamins D and K. And, no, there is no convincing evidence that calcium supplements cause stones.
Questions regarding the safety of supplemental calcium arose 7 years ago when a researcher (Bolland, 2008) announced that taking calcium supplements could modestly increase a person's risk for a heart attack. This literally shocked the nutrition and osteoporosis research worlds.But close scrutiny by other researchers (check out my earlier blog on this topic) called into question both the design of this study, as well as the way Bolland interpreted his results. There has been a raging debate and LOTS of misinformation being disseminated ever since. Some professionals say "just get your calcium through food" while others say "taking supplemental calcium is not only perfectly safe but can be very beneficial to your bones".
With so many people taking calcium to improve their bone health, the Council for Responsible Nutrition (CRN) stepped in last year to take a good look at all the evidence. Their results:
"Although there was no overall indication of a connection between calcium intake and atherosclerotic heart disease or stroke, a few of the cited studies showed a weak but statistically significant positive association of calcium intake and cardiovascular disease, whereas a similar number show the opposite (protective) effects. Because of these mixed results, Heaney and colleagues determined that the findings from available clinical trials and prospective cohort studies indicated that there is no significant effect of calcium supplements on cardiovascular disease (Heaney, et al., 2012)."
The CRN went on to say: "A wide range of clinical and epidemiological studies discussed by the IOM, the EC SCF, the EVM and several published reviews and meta-analysis have shown no adverse effects with calcium intakes of 2,000 mg or less in adults ages 51 years or older. Based on the judgement of the IOM, the calcium UL for persons aged 19 through 50 years should be 2,500 mg, which is the midpoint between the value for individuals ages 51 years and older and the 3,000 mg UL for adolescents. Considering the quite variable calcium intake from foods, dairy products, and fortified foods, CRN agrees with the EVM that a maximum supplement level for adults should be 1,500 mg. Thus, the CRN UL for supplemental calcium is set at 1,500 mg per day for adults."
When I went to the 2013 American Society for Bone and Mineral Research Annual Meeting in Baltimore, Maryland the question over the safety of supplemental calcium was a huge topic. I spoke with several researchers and the answer was always the same. "Supplemental calcium is safe." A sampling:
Douglas Bauer, et al. Dietary and supplemental calcium intake and the risk of mortality in older men: the MrOS study concluded: "...there was no evidence that supplements increased the risk of mortality among those with the highest dietary calcium intake..." and, "...calcium supplements and the combination of high dietary calcium intake and supplement use were not associated with total or cardiovascular mortality."
Joshua Lewis, et al. The cardiovascular safety of calcium supplementation with or without vitamin D in elderly women: A collaborative meta-analysis of published and unpublished trial level evidence from randomized controlled trials concluded: "The data from this meta-analysis does not support the concept that calcium supplementation with or without vitamin D increase the risk of ischemic heart disease or total mortality in elderly women."
I hope this helps clarify the question about the safety of calcium supplements. Our OsteoSustain has 525 mg of calcium in three caplets. That is 175 mg in each caplet. This amount was chosen for a reason during the formulation process of this product. Obtaining adequate calcium is vital for skeletal health but we also know that it is not good to ingest high amounts of calcium all at once. Since it is virtually impossible to obtain adequate calcium and magnesium from one's diet alone, we need to supplement. This is ESPECIALLY true if you are osteoporotic. But we also want to avoid a "spike" in blood calcium levels...a problem that could potentially interfere with normal heart rhythms. This has been shown (although research has not determined if this has any long term detrimental effect) when a person ingests 500 mg or more of calcium all at once.
Our OsteoMineralBoost contains 140 mg calcium in each caplet. Once again, a very manageable amount of calcium for the body to assimilate without causing any excess spike of calcium in the blood. Taking 3 caplets of OsteoSustain throughout the day (not all at once)* and 1 to 2 caplets of OsteoMineralBoost (also spread throughout the day)* gives a person between 665 mg and 805 mg supplemental calcium. With another 600 mg or so of calcium from the diet, this is PERFECT for someone with bone loss. In addition, with OsteoSustain and OsteoMineralBoost you are also getting bioavailable magnesium, vitamins D and K, and trace minerals...all important for utilizing the calcium and helping your body put this vital mineral where it belongs...in your bones.
For the second question: Do calcium supplements cause kidney stones? With literally hundreds of research studies asking this exact question over the past 25 years you would think we would know the answer to this question. But studies have been conflicting. In an attempt to analyze all of this material, Candelas et al. (2012) did a systematic review from three sources to determine the answer. Candelas examined: 1) Medline and Embase from 1991 to 2010. 2) Cochrane Centered register of Controlled Trials up to 2010, and 3) Abstracts from the annual meetings of the American College of Rheumatology and the European League Against Rheumatism from 2008 thru 2010. Candelas' conclusion: "Calcium supplements in the treatment of osteoporosis alone or in combination with another type of treatment does not significantly increase the risk of nephrolithiasis or renal colic."
From both my clinical and personal experience, I know how important it is for people with osteoporosis to consume (and absorb) adequate calcium. This mineral is vital for improving bone health. But so too are vitamins D and K, and trace minerals. When taken on a regular basis, these nutrients will provide a safe and effective approach to improving skeletal health.
*If you choose to take 3 OsteoSustain and 2 OsteoMineralBoost per day it is difficult to completely spread these 5 caplets out throughout the day by taking them one at a time. Therefore, it would be perfectly fine to take 2 caplets at a time. For example: Breakfast - 2 OsteoSustain, Lunch - 2 OsteoMineralBoost, Dinner - 1 OsteoSustain. (or any other combination you desire)
Boland, M.J., et al. 2008. Vascular events in healthy older women receiving calcium supplementation: randomised controlled trial. BMJ. Feb 2,336(7638):262-6.
Boland M.J. and Reid I.R. 2011. Calcium supplements with or without vitamin D and risk of cardiovascular events: reanalysis of the Women's Health Initiative limited access data set and meta-analysis. BMJ. 342:d2040.
Hathcock, J.N. 2014. Vitamin and Mineral Safety, 3rd Edition. Council for Responsible Nutrition, pp 104-110.
Candelas, G., et al. 2012. Calcium supplementation and kidney stone risk in osteoporosis: a systematic literature review. Clinical and experimental rheumatology. Nov-Dec., 30(6):954-61.