Calcium is a major mineral essential for human health. In addition to playing an important role in building and maintaining strong bones and teeth, calcium aids in muscle contraction and regulates blood pressure. In fact, consuming a diet rich in calcium, along with other minerals, such as potassium and magnesium, is recommended for reducing blood pressure.
How it Works
Calcium may reduce blood pressure because it plays a vital role as a mediator in the constriction and relaxation of blood vessels, according to the Linus Pauling Institute at Oregon State University. Similarly, calcium is essential for muscle contraction and relaxation. Consuming a calcium-deficient diet causes a concentration of calcium ions in the intercellular fluid. This elevates both the active form of vitamin D, vitamin D3, and the parathyroid hormone resulting in an increased calcium concentration in smooth muscle cells. This shift in calcium concentration increases vascular resistance, raising blood pressure according to an article published in the Journal of the American College of Nutrition in February 2009.
According to an article published in the Journal of Human Hypertension in August 2006, calcium supplementation reduces blood pressure in individuals with hypertension. In this article, researchers summarized the findings from 40 studies that included nearly 2,500 participants. Roughly half of the participants suffered from hypertension. The average length of the clinical trials was 10 weeks and supplementation was approximately 1,200 mg of calcium daily. The overall reduction in blood pressure post supplementation was 1.9 points for systolic blood pressure and a 1.0 point drop in diastolic blood pressure.
The National Health, Lung, and Blood Institute or NHLBI, recommends making lifestyle modifications to treat hypertension. One such modification is to adopt the DASH diet guidelines, or the Dietary Approaches to Stop Hypertension. In addition to consuming a low-sodium diet and increasing your intake of foods rich in magnesium and potassium, the DASH diet promotes the consumption of plenty of calcium-rich foods. Individuals on a 1,600-calorie diet should strive to take in two 8-ounce servings of fat-free or lowfat milk or yogurt while those on a 2,600-calorie diet require at least three 8-ounce servings.
The Recommended Adequate Intake, or AI, for calcium for adults is 1,000 milligrams daily. However, according to the NHLBI, the daily nutrient goals used in the DASH scientific studies were higher, on average, by 200 mg. Per DASH diet guidelines, you should strive to consume approximately 1,250 mg of calcium daily. This may come from food sources alone, dietary supplements, or a combination of food sources and dietary supplements.
Calcium-rich foods include dairy products, such as yogurt and milk. Cheese is calcium-rich but also high in sodium. The calcium in milk and yogurt is typically well absorbed and used efficiently by the body. An 8-ounce glass of milk provides about 300 mg of calcium. An 8-ounce container of yogurt provides anywhere from 250 mg to 350 mg of calcium. Calcium-fortified orange juice provides just as much calcium as milk, about 300 mg. A benefit of choosing calcium-fortified orange juice is that it is also an excellent source of potassium.
- Linus Pauling Institute: Oregon State University: Calcium
- Journal of the American College of Nutrition: Milk products, dietary patterns and blood pressure management
- Journal of Human Hypertension: Blood pressure response to calcium supplementation: a meta-analysis of randomized controlled trials
- The National Health, Lung, and Blood Institute: DASH Diet