Question: Several years ago, the Listener published an article about research from the University of Auckland which found calcium supplements could cause a stroke. I suffered a stroke. I was taking calcium supplements to relieve arthritic pain at the time. I was a healthy 77-year-old, still active on my farm, with minimal heart disease and a BMI of about 24. When I told my cardiologist I had been taking a lot of calcium supplements, he was very dismissive and didn’t think they were a problem.
Answer: Decades ago, calcium supplementation was widely promoted for bone health, with many believing it would reduce the risk of hip fractures and improve bone density. However, the professional view on calcium supplements has taken a significant turn since then. Indeed, Distinguished Professor Ian Reid and Associate Professor Mark Bolland from the University of Auckland wrote in the Medical Journal of Australia that they “have very little place in contemporary medical practice”.
To clarify, “very little place” does not mean there is no place for them. But there is only a very narrow window in which the benefits of calcium supplements outweigh their risks. And that window does not include otherwise healthy older adults.
For starters, Reid and Bolland noted in their 2019 article that these supplements have minimal impact on bone density. Indeed, a 2015 meta-analysis found just a 1% increase in bone density over one year, with no further improvement even with ongoing supplementation. An increase that small would not feasibly affect fracture risk, a fact borne out in clinical trials, with no evidence that calcium supplements reduce fracture risk.
Those who take them are prone to gastrointestinal complaints, particularly constipation. Moreover, they are twice as likely to be admitted to hospital for abdominal symptoms and have a 17% greater risk of kidney stones, Reid and Bolland say.
Added to that is the evidence that calcium supplements increase the risk of a heart attack and possibly may also increase the risk of stroke – though this finding is still mired in controversy, perhaps explaining your physician’s response.
In limited cases, they may be beneficial, such as specific treatment regimes for osteoporosis and when an overt deficiency exists. But beyond these cases, the safety concerns about their use outweigh any potential health benefit.
Reid and Bolland’s view is broadly in line with that of the International Osteoporosis Foundation, which states that “supplementation with calcium alone for fracture reduction is not supported by the literature”. However, in patients at high risk of calcium and vitamin D deficiency, a combination treatment of calcium and vitamin D supplementation is supported.
So, there is no benefit to taking a calcium supplement in the absence of a diagnosed deficiency or evidence-based medical need – and, potentially, a genuine risk.
In your case, there is no evidence to suggest that calcium supplements would have a beneficial effect on your arthritis; however, you ultimately can speak to your own pain and experiences with arthritis.
But when balancing the real risks of calcium supplementation against the studied benefits for arthritis, the answer is a net negative.
Reid and Bolland conclude that “a recommendation not to provide supplements routinely to healthy older individuals can be judged to be evidence-based, as defined by the GRADE methodology, and no longer a matter of controversy.”
Did the calcium supplements cause or contribute to your stroke? We may never know. But at the risk of further complications, if you haven’t already, it may well be wise to cut your losses now and ditch them.
This article originally appeared in the NZ Listener’s April 2, 2022 edition.
