Confusion still reigns in the world of calcium but it is becoming increasingly clear that we do not need calcium supplements to maintain healthy bones. Moreover, a recent study found that calcium supplementation can increase “cardiovascular events” (an interesting name for things like heart attacks). So it is nice that we do not have to choose between heart health and bone health.
The latest study on calcium reviewed the data of thousands of Swedish women. It concluded that increasing total intake of calcium above 750 mg did not prevent osteoporosis but did increase increase the incidence of hip fractures. These results are similar to those of the Bischoff study we discuss in class. Presently, the FDA recommends 1200 mg/day for postmenopausal women and men over the age of 71. It recommends 1000 mg/day for other adults and 1300 mg/day for teenage girls. Likely these recommendations will eventually change given meta-reviews showing that calcium in excess is not good for heart or bone health.
We do still need calcium. The Swedish study associated getting less than 750 mg/day with an increased risk of fracture and of osteoporosis. This number may still be at the high end of what you need, depending on your life style: The Swedish study reviewed data on Swedish women: Living far north, they are at risk for low vitamin D and vitamin D affects how the body uses calcium. It looked at how much vitamin D these women ate but did not measure their actual vitamin D levels. It did note that the lower the vitamin D intake, the more calcium needed to prevent fractures. Thus, a person with more adequate vitamin D stores might need less calcium.
Swedes also eat a diet high in animal protein. There are studies suggesting that avoiding excess protein may help the body preserve calcium, thereby reducing the amount of calcium needed in the daily diet.
The United Kingdom and Scandinavia recommend a daily intake of calcium of 700 (UK) or 800 (Scandinavia) mg/day. Studies are now accumulating that strongly suggest that when we exceed those amounts we increase our risk of heart problems, increase our risk of hip fractures, and do nothing to prevent osteoporosis. Something to think about, especially if you are the average post-menopausal American woman eating plenty of dairy and taking a daily calcium supplement as well.**
(Warensjo, E, Byberg L, Melhus H, et al. Dietary calcium intake and risk of fracture and osteoporosis: prospective longitudinal cohort study. BMJ 2011;342:d1473)
** Many Americans eat a calcium-rich diet and take supplements. Thus, according to the FDA, most postmenopausal women exceed the recommended 1200 mg of calcium/day.