Humphrey Davey wanted to study medicine. He was an apprentice to a surgeon and apocathery. But Davey never did study medicine. Instead, he became a self-taught chemist and he discovered several elements including calcium.

The narrative surrounding calcium supplementation is as complex as it is fascinating. Calcium supplementation has roots deeply embedded in both science and societal beliefs. Calcium, the stalwart of bone health, has been championed for decades as a critical component of a healthy lifestyle. This has been particularly the case in improving bone health. This belief has not only permeated clinical guidelines but also the public consciousness. Consequently, a significant portion of the population, especially older women, incorporate calcium supplements into their daily regimen. In the United States alone, a striking 61% of women over 60 were taking calcium supplements between 2003 and 2006. This widespread adoption has catapulted calcium supplementation into a billion-dollar industry. Millions of people across various age groups seek to bolster their health through calcium supplements.

Are Calcium Supplements Safe?

Yet, the message of “more calcium equals better health” is increasingly being questioned. Initial studies posited that dietary calcium had a more pronounced effect on bone building compared to its supplemental counterpart. This is presumably due to its better absorption. Yet, the reality of dietary habits and the availability of calcium-rich foods means not everyone can achieve sufficient calcium intake through diet alone. All the more so with the recent trend towards milk substitutes. This underscores a potential role for supplementation in cases of dietary inadequacy.

But as the practice of calcium supplementation has grown, so too have concerns about its safety. Recent years have seen a burgeoning debate. The discourse has been fueled by studies suggesting potential risks associated with indiscriminate calcium supplementation. Notably, a meta-analysis by Bischoff-Ferrari et al. highlighted an increased risk of hip fractures. A review of randomised clinical trials found that calcium supplementation did not correlate with a reduced risk of fractures among older adults. So, there was certainly evidence to suggest an either negative or at best neutral effect of calcium supplements on the risk of hip fractures. Remember, the main reason to take calcium is to avoid a devastating hip fracture. However, this discourse took a more concerning turn than merely suggesting a lack of benefit. Other findings suggested a significant increase in cardiovascular disease associated with calcium supplements. This was particularly the case in men.

Are Calcium Supplements Harmful?

Amidst this backdrop, the recent findings from a study leveraging the expansive UK Biobank dataset provide a nuanced perspective on the intersection of calcium supplementation and cardiovascular health. The research examined the associations between calcium supplementation and cardiovascular disease (CVD) events and mortality. In particular, it examined supplementation in individuals with and without diabetes. The results painted a stark picture for those with diabetes. Regular calcium supplement intake was linked to higher risks of heart disease and death in diabetics. No significant risk increase was observed in participants without diabetes.

This dichotomy between individuals with and without diabetes underscores the need for a more tailored approach to calcium supplementation. It also challenges the prevailing “one-size-fits-all” mentality. The study’s implications are profound. It suggests healthcare providers weigh the potential adverse effects of calcium supplements against their benefits, particularly among diabetic patients.

The dialogue surrounding calcium supplementation, once dominated by an uncritical endorsement of its benefits, is evolving. It calls for a reevaluation of how we perceive and prescribe these supplements. I would advocate for a balance that prioritises dietary sources of calcium. Supplementation should be recommended judiciously. The study serves as a reminder of the importance of personalised healthcare and the value of diet over supplements.

Dr J Hugh Coyne

Private GP

Coyne Medical