09 Nov Cardiovascular Risk: Effects of High Dose Calcium Tablets
MedicalResearch.com Interview with:
Joshua Lewis, Ph.D
Raine Foundation / Alan Robson Fellow
Bone and Vascular Research Group
School of Medicine and Pharmacology
University of Western Australia
Department of Endocrinology and Diabetes
Sir Charles Gairdner Hospital
Hospital Avenue, Nedlands 6009
MedicalResearch.com: What are the main findings of the study?
Dr. Lewis: The paper reports the findings from an ancillary study of the effects of 1200 mg per day of calcium supplementation on a major predictor of heart disease risk, carotid artery intima-medial thickness and atherosclerosis. The principle study was a large five-year double blind randomized controlled trial of calcium supplements or a placebo. After 3 years of calcium supplementation or placebo measures of carotid artery intima-medial thickness were identical in the placebo and calcium treated patients. Atherosclerotic plaque was reduced in calcium treated patients when analysed as total calcium intake. These findings argue strongly against an adverse effect of high dose calcium tablets on cardiovascular risk.
MedicalResearch.com: Were any of the findings unexpected?
Dr. Lewis: The reduction in carotid atherosclerotic plaques, associated with reduced cardiovascular risk in other studies, is supportive of the mainstream view that calcium supplementation does not increased cardiovascular risk in women.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. Lewis: Our findings demonstrate that where elderly women cannot meet the recommended daily intake of calcium (1000 – 1300 mg calcium per day) from the diet alone, supplementation with up to 1,200mg per day does not increase cardiovascular risk.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Dr. Lewis: In view of the fact many patients have been confused by recent press speculation on the risks of calcium supplementation despite the evidence for the beneficial effect and safety of calcium and vitamin D supplementation, a focused large multicentre randomised controlled trial of calcium supplementation with vitamin D should be undertaken to address the magnitude of the fracture reduction in those at increased risk of fracture with inadequate calcium intake and reduced vitamin D formation because of inadequate sun exposure. In addition to assessing skeletal benefits of supplementation the study of cardiovascular risk factors and clinical outcomes would also need to be included.
The Effects of 3 Years of Calcium Supplementation on Common Carotid Artery Intimal Medial Thickness and Carotid Atherosclerosis in Older Women: An Ancillary Study of the CAIFOS Randomized Controlled Trial