In a meta-analysis published in the British Medical Journal on 29th July ,2010 which included 11 randomized , double blind trials and 12,000 participants, the investigators reported that calcium supplements ( without co administered vitamin D ) are associated with an increased risk of myocardial infarction. The authors recommended that reassessment of the role of calcium supplements in the management of osteoporosis is warranted.
Saudi Osteoporosis SOCIETY comment :
This is an important study since most osteoporotic patients as well as normal post menopausal subjects are on calcium supplements. It is to be noted however that the studies included were those in which vitamin D was not co administered . Vitamin D is known to have possible favorable effects on the heart so it is difficult to predict from this meta-analysis the effects of the combination ( which most patients are advised to take ). Overall the society would like to stress on the following points:
1- The metanalysis showed increased risk of M.I. but failed to show increase in mortality which is unexplainable.
2- The studies included in the metanalysis were of short durations (median follow up of 3.6 years). This is very short period to have possible harmful effects of Calcium like coronary calcifications
3- These metanalysis were done in populations with calcium sufficiency which is different from our population in Saudi Arabia. Finding might not apply to this part of the world with large percentage of the population having Vitamin D deficiency and are not taking proper dietary calcium.
4- Most of our patients are on both Calcium and Vitamin D supplements for the above reason. The study showed excess M.I. risk in patients who are calcium sufficient taking only calcium supplements without Vitamin D. There is some evidence for protective cardiovascular effects for Vitamin D in some studies.
The Saudi Osteoporosis Society advice our patients not to stop their calcium and Vitamin D intake tell further evidence becomes available.
The Saudi Osteoporosis Society will carefully monitor and follow on any future studies or reports on this issue for its members.
Bolland M J , Avenell A , grey A , Maclennan aG ,Reid I . Effect of calcium supplemnts on risk of myocardial infarction and cardiovascular events : meta-analysis . B M J 2010; 341:
Yousef AL Saleh, MD