Calcium and vitamin D supplements are widely taken to support bone health, especially by older adults. But a large review published in The BMJ suggests that, for most older people, these supplements provide little to no meaningful protection against falls or broken bones.
Falls are a major health concern as people age. Nearly one in three adults aged 65 and older falls each year, and those falls can lead to fractures, chronic pain, loss of independence, reduced quality of life, and in some cases a move into residential care. Finding effective ways to prevent falls and fractures is therefore an important public health goal.
Longstanding Questions About Bone Supplements
Calcium and vitamin D have long been associated with bone health. Calcium is a major structural component of bone, while vitamin D helps the body absorb calcium and supports normal bone metabolism.
Even so, previous evidence reviews have generally found that taking calcium or vitamin D alone does not reduce fracture risk. Results have been less consistent when the two are taken together, and researchers have also remained uncertain about whether vitamin D can meaningfully reduce falls.
Despite those unanswered questions, vitamin D supplements (with or without calcium) are still commonly recommended by clinicians, guidelines, and regulatory agencies for bone health. Prescriptions have also risen substantially in recent years.
Researchers Reviewed 69 Randomized Trials
To get a clearer picture, researchers in Canada examined results from 69 randomized controlled trials involving 153,902 adults.
Randomized controlled trials are considered one of the strongest ways to test whether a treatment works because participants are assigned to different treatment groups, helping researchers reduce the influence of other factors.
The trials compared calcium supplements, vitamin D supplements, or a combination of the two with either a placebo or no treatment. Researchers focused on whether the supplements reduced fractures and falls.
The studies varied in quality, but the team assessed the risk of bias and the certainty of the evidence using established research methods.
Little Evidence of Meaningful Fracture Prevention
After setting thresholds for what would count as a clinically meaningful benefit, the researchers found little to no effect on the chance of experiencing any fracture.
For calcium supplements, that conclusion was based on moderate certainty evidence from 11 trials involving 9,067 participants.
For vitamin D supplements, the researchers found high certainty evidence from 36 trials involving 92,045 participants.
For calcium and vitamin D taken together, high certainty evidence from 15 trials involving 51,126 participants also showed little to no meaningful effect.
The same general pattern appeared when researchers looked at specific outcomes, including hip fractures and falls. Calcium, vitamin D, and combined supplementation all appeared to have little to no effect, with most of the evidence rated as moderate to high certainty.
Important Exceptions Remain
The researchers caution that some parts of the analysis were based on relatively small numbers of trials or participants, meaning those findings should be interpreted carefully.
The conclusions may also not apply to everyone. In particular, people with certain bone disorders or those receiving medication for osteoporosis may have different needs and should not assume the findings apply directly to them.
Still, the results remained broadly consistent when researchers accounted for factors including age, sex, previous fractures, previous falls, and average calcium intake from food. That consistency strengthened confidence in the overall conclusions.
Researchers Question Routine Supplementation
Based on the findings, the researchers say the evidence “does not support routine supplementation with calcium or vitamin D, or combined supplementation to prevent fractures and falls.”
They also argue that clinicians, guideline panels, and regulatory agencies “should re-evaluate their general recommendations for calcium and vitamin D supplementation in light of current evidence.”
Researchers writing in a linked editorial say more rigorous and well-powered trials are still needed to determine whether supplementation might benefit people at especially high risk.
Exercise May Offer More Meaningful Protection
For now, the editorial authors suggest shifting more attention and funding toward approaches that have already shown meaningful benefits for preventing falls and related injuries.
Those strategies include balance training and resistance exercise, which can help improve strength, stability, and physical function.
Programs that combine several approaches may also be useful. These can include exercise, assessment of hazards that could contribute to falls, and education tailored to a person’s individual risk.
Taken together, the findings suggest that preventing falls and fractures in older adults may require more than simply adding calcium or vitamin D supplements to a daily routine.
