Why Kiwi Is a Tiny Fruit Rich in Magnesium, Calcium, and Heart Benefits

Getting enough magnesium and calcium from food each day does not have to be difficult. Some foods provide both minerals at once, and one especially small fruit with an unusual look does exactly that: kiwi. It can have green or yellow flesh, edible seeds, and a fuzzy skin, and the skin can be eaten too.

Although a kiwi is usually small enough to fit in your hand, it delivers a solid nutritional package. One kiwi contains about 26 milligrams of calcium and 12 milligrams of magnesium, plus 145 milligrams of potassium and 2.25 grams of fiber. It also provides 56 milligrams of vitamin C and just 48 calories.

Because of that nutrient mix, kiwi may help support cardiovascular health and reduce the risk of heart attack or stroke. That matters for everyone, since heart disease is the leading cause of death in the United States, according to the U.S. Centers for Disease Control and Prevention.

How a small fruit may affect cardiovascular health

In a 2014 study published in Blood Pressure, participants with mildly elevated blood pressure ate three kiwis a day for eight weeks. Compared with a control group that ate one apple a day, the kiwi group had slightly lower systolic and diastolic readings, by 3.6 and 1.9 millimeters of mercury, respectively. In another trial published in Nutrients, participants ate two kiwis each morning for seven weeks. By the end of the study, their systolic blood pressure was 2.7 mmHg lower than that of a control group that did not eat kiwi.

Several nutrients in kiwi may help explain the effect. Plant-based fiber has been linked to lower blood pressure, and a review in Cureus suggested it may help by relaxing blood vessel walls, supporting gut health, and encouraging healthy insulin function. Potassium is also associated with lower blood pressure, since it helps balance out excess sodium from salty foods.

Benefits beyond blood pressure

A 2024 review in Cureus suggested that because cardiovascular problems are tied to magnesium deficiency, magnesium supplementation could be a useful approach for certain heart conditions. Calcium may matter too. In a Cleveland Clinic podcast, registered dietitian Julia Zumpano said low calcium could be a risk factor for high blood pressure, and cardiologist Dr. Martha Gulati has also noted that calcium deficiency can contribute to elevated blood pressure.

Even people who are not focused on blood pressure may still benefit from adding kiwi to their diet, especially if they want to reduce the chance of getting sick. Registered dietitian Gillian Cuthbertson told the Cleveland Clinic that kiwi can help fight illness because it contains antioxidants, including vitamin C. She said antioxidant-rich foods such as kiwi may lower the risk of diseases, including some cancers and heart conditions, and noted that getting antioxidants from food is preferable to relying on supplements because nutrients are more bioavailable that way.