Calcium helps blood vessels tighten and relax when they need to. Magnesium does that, too, and is also needed for energy production and moving calcium and potassium around the body. Potassium lowers blood pressure and protects against muscle cramping and an irregular heartbeat.
How much of these nutrients do adults need? Here are the Recommended Dietary Allowances (RDA) for all three:
- Calcium: 1,000 milligrams (mg) for women ages 31 to 50, and 1,2000 mg after that; 1,000 mg a day for men ages 31 to 70 and 1,200 mg after that;
- Magnesium: 320 mg a day for women ages 31 and older; 420 mg for men ages 31 and older
- Potassium: 4,700 mg a day for everyone age 14 and older
These minerals are found in many common foods. Good sources of calcium include milk and dairy foods, fish with bones (such as canned salmon and sardines), and dark, leafy greens. Magnesium is plentiful in dark, leafy green vegetables, unrefined grains, and legumes. Good sources of potassium include sweet potatoes, prunes, apricots, and lima beans.
"People eating a healthy diet probably have nothing to worry about. But people eating a diet of processed and canned foods might need to be concerned" that they aren't getting enough of these key minerals, says Dr. Randall Zusman, director of the Division of Hypertension at the Massachusetts General Hospital Heart Center.
Read the full-length article: "Key minerals to help control blood pressure"
Also in the August 2014 issue of the Harvard Health Letter:
- Exercise = free medicine
- Easy ways to prevent falls and protect mobility
- Pill-free ways to restore a sex life
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