Women have long been advised to take high doses of supplemental calcium to protect their bones, but a new study from China suggests that this may not be good advice for all. More than 300 women were randomized to receive either 800 mg of calcium or placebo daily for two years.
Women who had not yet entered menopause had no bad effects from these supplements, but postmenopausal women taking calcium had higher cholesterol and thicker walls in their carotid arteries. Whether these effects of calcium supplementation actually increase the risk of heart attacks and strokes in postmenopausal women remains unknown, but generally thicker arterial walls and higher cholesterol are considered cardiovascular risk factors.
[American Journal of Clinical Nutrition, online Sept 18, 2013]
Some previous research also indicated that calcium supplements may have a negative impact on cardiovascular health. In one Swedish study, women who took calcium tablets in addition to getting calcium from their diets were twice as likely to die during the 20-year follow-up period as women who did not take supplements.
One reader, Karen, made this observation about the calcium supplement quandary: “It strikes me that if we told concrete providers to ‘simply add more sand’ to their mix, we’d be screaming when our concrete structures collapsed.
“But that’s what happens when the only one supplement is advised for osteoporosis. Bones are more than calcium. Overdosing on any one ingredient in a recipe would not produce the desired result; it rather astounds me that we expect it to work in our bodies.
“And even more than concrete, our bones are strong in part because of what we ask them to do. Load bearing exercise increases bone strength. If you never ask your bones to do anything, then they can’t do anything when you need them to in a pinch.”
For information on keeping bones strong after menopause without loading up on supplemental calcium, you may want to listen to our radio show Bone Vitality, with Dr. Walter Willett and Michael Castleman, author of Building Bone Vitality: A Revolutionary Diet Plan to Prevent Bone Loss and Reverse Osteoporosis.
