(HealthDay News) — Extra calcium may not protect aging bones after all, according to findings from two reviews published in The BMJ.
One review focused on two dietary studies that compared how patients aged older than 50 years fared when instructed to consume higher vs. lower levels of calcium. The research team also looked at 44 studies that explored how long-held calcium, milk, dairy and/or supplement routines affected fracture risk. Another 26 studies examining the impact of calcium supplements were also analyzed.
The conclusion: None of the research provided any evidence that calcium intake is associated with fracture risk.
The second review focused on 59 studies that looked at the effect of calcium from either food or supplements on bone mineral density (BMD) in patients over 50.
Boosting calcium intake in whatever form was associated with a small increase in BMD, but investigators concluded that the 1% to 2% increase detected had no meaningful impact on fracture risk.
Karl Michaëlsson, MD, PhD, a professor in the department of surgical sciences at Uppsala University in Sweden and author of an accompanying journal editorial, said the review findings are clear: More is not necessarily better. Too much calcium and/or vitamin D, which is usually recommended with calcium, can lead to “more hip fractures and an increase in the risk of cardiovascular disease,” Michaëlsson told HealthDay.
For clinicians and researchers, he offered this advice: “Move the focus from a general recommendation to increase intakes of both calcium and vitamin D to very high levels to instead define a valid insufficiency level for calcium intake and to better determine a low vitamin D status.”
- Bolland MJ, Leung W, Tai V, et al. Calcium intake and risk of fracture: systematic review. BMJ. 2015;doi:10.1136/bmj.h4580.
- Tai V, Leung W, Grey A, Reid IR, Bolland MJ. Calcium intake and bone mineral density: systematic review and meta-analysis. BMJ. 2015;doi:10.1136/bmj.h4183.
- Michaëlsson K. Calcium supplements do not prevent fractures. BMJ. 2015;doi:10.1136/bmj.h4825.