Review: calcium and vitamin D dont protect bones as thought
A new review of 69 trials in nearly 154,000 people, published in The BMJ, finds little to no benefit from calcium and vitamin D supplements for preventing fractures and falls.
- The review covers 69 randomized trials with 153,902 adults.
- The conclusion: calcium, vitamin D or the two combined offer little to no clinically meaningful benefit for preventing fractures and falls.
- The authors do not support routine supplementation for prevention, though the finding does not apply to people with bone disorders.
- An accompanying editorial recommends balance training and strength exercise as a better choice.
A team of Canadian researchers led by Olivier Masse published a review in The BMJ on June 15 that challenges one of the most widespread pieces of advice in medicine, that calcium and vitamin D supplements protect bones. The study finds that these pills offer little to no clinically meaningful benefit in preventing fractures and falls in adults.
Advice to take calcium and vitamin D has been part of everyday practice for decades, especially for older people and women going through menopause. The logic was simple: if bones lose minerals with age, topping them up through supplements should slow that process and cut the risk of hip, spine and other fractures. The new review does not bear out that common-sense chain.
What did the researchers actually measure?
This is a systematic review and meta-analysis, meaning it pools the results of existing studies into one large picture. The authors included 69 randomized controlled trials, the type of study considered most reliable because it assigns participants at random to a group taking the supplement and a group taking a placebo. The combined sample was 153,902 adults, which makes this one of the largest reviews on the topic so far.
When the results of all the trials were added together, calcium alone, vitamin D alone, and the two combined showed an effect too small to be clinically meaningful. In other words, the difference in fractures and falls between those who took supplements and those who did not was so slight that it does not change the outcome in everyday life. For that reason the authors do not support routine calcium and vitamin D supplementation in the general population to prevent fractures.
A clear line is worth drawing here. The review concerns healthy adults and should not be read as advice for people who already have diagnosed bone disorders or who are on osteoporosis therapy. For them, treatment is guided by doctors based on the individual case, and this finding does not change that.
So what does help bones?
An editorial published alongside the review offers a practical direction. Rather than relying on pills, the authors recommend balance training and strength exercise, since stronger muscles and better stability lower the chance of a fall, and a fall is the most common immediate cause of fractures in older people. It is a shift in focus from what we take in to what we do with the body.
It is worth being precise about what the study does not prove. It does not claim that calcium and vitamin D are harmful, nor that a diet short of these nutrients carries no consequences. The question is about supplements as a preventive measure in people who are not deficient, not about severe vitamin D deficiency, which remains a medical problem in its own right. Meta-analyses also pool trials of varying quality and length, so individual results may differ.
The message is still clear enough to prompt a conversation with a doctor instead of an automatic trip to the pharmacy. Would you place your trust in a tablet, or in regular exercise for strength and balance?
