…at least in post-menopausal women on the diet for two years. AJCN has the details:
“It has been hypothesized that hip-fracture rates are higher in developed than developing countries because high-protein (HP) Western diets induce metabolic acidosis and hypercalciuria. Confounders include interactions between dietary protein and calcium, sodium, and potassium.”
“High dietary protein intake [at least 90 grams/day] during weight loss has no clinically significant effect on bone density….”
Six of every 10 middle-aged and older women in the U.S. are taking calcium supplements, hoping to keep their bones strong and thereby avoid osteoporotic fractures of the hip, spine, and wrist. A new study in the British Medical Journal suggests that high calcium consumption, whether from food or supplements, increases the risk of death.
The researchers wrote:
In this study of women in the Swedish mammography cohort, a high calcium intake (>1400 mg/day) was associated with an increased rate of mortality, including death from cardiovascular disease. The increase was moderate with a high dietary calcium intake without supplement use, but the combination of a high dietary calcium intake and calcium tablet use resulted in a more pronounced increase in mortality. For most women with lower intakes we observed only modest differences in risk.
A new European study suggests that calcium supplements almost double the risk of having a heart attack, at least in Germans. You can read the full report in the current issue of Heart.
The medical literature on this issue is a confusing mess. In other words, lots of conflicting results.
Huge numbers of women in the U.S. are taking calcium supplements either to treat or prevent osteoporosis and the associated broken bones (e.g., hips, wrists, spine).
What I’d like to know, and what nobody knows, is what is the effect of calcium supplementation on average longevity and quality of life. Maybe I’d accept a higher risk of heart attack if calcium supplementation prolonged lifespan by two years.
In the interest of brevity, I’ll just say that the best way to get your calcium is probably through food rather than supplements.
Shereen Jegtvig has an article at About.com listing foods rich in calcium.
Exercise can also help keep your bones strong and break-resistant.
Steve Parker, M.D.
PS: If your doctor has you on a calcium supplement, you’d best get his blessing before you stop it.