A new study of over 36,000 American adults indicates that excessive dietary calcium intake in evening meals may elevate the risk of cardiovascular disease. The study suggests that circadian rhythms play a role in the absorption of calcium, with daylight hours being the optimal time for this process. However, an excess of calcium, particularly from supplements, can contribute to cardiovascular problems. Researchers propose that reducing calcium intake during dinner and increasing it during breakfast could potentially lower the risk of cardiovascular disease. The study, published in BMC Public Health, examined the dietary calcium intake of participants from the National Health and Nutrition Examination Surveys between 2003 and 2018, finding that spreading calcium intake over breakfast and dinner was the most effective in reducing cardiovascular disease risk.
The study excluded individuals under 20 years old, pregnant women, those using calcium supplements, individuals consuming over 4,500 kilocalories a day, and those with incomplete data. Ultimately, the researchers discovered that substituting a 5% calcium intake from dinner with breakfast led to a 6% reduction in overall cardiovascular disease risk. While the study provides valuable insights, the authors acknowledge that other factors not considered in the study may influence the results. They emphasize the need for further research in cohorts of different races and countries to identify any variations or similarities.
Calcium is primarily known for its role in bone and teeth formation and maintenance, muscle contraction regulation, blood clotting, and heart muscle function. Cardiovascular disease is a leading global cause of death, with circadian rhythms potentially impacting nutrient absorption in the body. Some studies have shown that the circadian clock system can interact with nutrients to influence bodily functions. Research suggests that calcium absorption may be slightly higher during daylight hours due to certain hormones like parathyroid hormone being more active then. However, overusing calcium supplements can be problematic, potentially leading to hypercalcemia, heart arrhythmias, vascular inflammation, and other cardiovascular issues.
Registered dietitian nutritionist Melanie Murphy Richter emphasizes the importance of considering individual needs when deciding to take calcium supplements, as different types of calcium can have varying absorption rates and effects on the body. Richter suggests that older individuals, particularly peri-menopausal women, and those with dietary deficiencies may benefit from supplementation, while a balanced diet rich in calcium-rich foods may eliminate the need for supplementation. Registered dietitian Kristin Kirkpatrick suggests taking smaller portions of calcium throughout the day, either in the morning with vitamin D exposure or divided into smaller doses with meals for better absorption. Some supplements combine calcium with magnesium, vitamin D, and zinc to enhance bone support and increase calcium absorption.
Overall, the study highlights the potential impact of dietary calcium intake on cardiovascular disease risk, with recommendations to adjust calcium intake from dinner to breakfast. Further research is needed to fully understand the relationship between calcium consumption and cardiovascular health, taking into account individual factors and the effects of various types of supplements. The findings emphasize the importance of a balanced diet rich in calcium-rich foods to support overall health and potentially reduce the risk of cardiovascular disease.