The other side of the coin of osteoporosis treatment: Calcium supplements may be associated with increased risk of cardiovascular disease (CVD) events
The modern way of life has risen awareness of osteoporosis among older adults and its treatment with calcium supplements has become a common worldwide routine. According to NHANES data, calcium supplements are used by 43% of US adults. These facts determine that this population would appear to be at greater risk of developing the adverse consequences of positive calcium balance, including vascular calcification. Results of a longitudinal cohort study evaluating the association between calcium intake, from both foods and supplements, and atherosclerosis, as measured by coronary artery calcification (CAC) have recently been published in the Journal of the American Heart Association.
The authors studied 5448 adults free of clinically diagnosed CVD (52% female; aged 45–84 years) from the Multi-Ethnic Study of Atherosclerosis. Baseline total calcium intake was assessed from diet (using a food frequency questionnaire) and calcium supplements (by a medication inventory) and categorized into quintiles. Baseline CAC was measured by computed tomography, and CAC measurements were repeated in 2742 participants approximately 10 years later. After full adjustment for demographics, lifestyle factors, CVD risk factors, and use of calcium supplements, the researchers found that among participants with a baseline CAC of zero, the highest calcium intake (≥1453 mg) compared to the lowest intake (<434 mg) was associated with a 27% decreased risk for incident CAC, suggesting a protective effect of total calcium intake in the highest consumers of overall calcium. However, when considering supplement use, the risk of developing incident CAC was 22% higher in those who used supplements than those who did not.
The authors of the present study point out that their findings add further support to previously published reports by suggesting that the relationship between calcium intake and CVD risk is complex and appears to depend on the source of calcium intake, with dietary calcium generally showing a protective effect, but calcium supplement use being associated with increased risk. Rather than promoting bone health, excess calcium from the diet and supplements is postulated to accrue in vascular tissues.
“There is a hypothesis, that if the right amount of Vitamin K2 is added to a high calcium regimen it can be beneficial for cardiovascular system. Vitamin K2 promotes arterial flexibility by preventing arterial calcium accumulation, which could correct the imbalance of calcium in the body,” says Dr. Katarzyna Maresz, president of the International Science and Health Foundation. “Thus, calcium in tandem with Vitamin K2 may well be the solution for bringing necessary bone benefits while circumventing an increased risk for heart disease,” she emphasizes.
“However, there is lacking clinical trial, which proves this hypothesis. At least for now, we can say that supplementary calcium can be dangerous for your cardiovascular health, when vitamin K2 supplementation can bring beneficial effect,” Dr. Maresz concludes.
Anderson JJB, Kruszka B, Delaney JAC, He K, Burke GL, Alonso A, Bild DE, Budoff M and Michos ED. Calcium Intake From Diet and Supplements and the Risk of Coronary Artery Calcification and its Progression Among Older Adults: 10‐Year Follow‐up of the Multi‐Ethnic Study of Atherosclerosis (MESA). Journal of the American Heart Association. 2016;5:e003815, originally published October 11, 2016 http://dx.doi.org/10.1161/JAHA.116.003815