Dolomite is a type of limestone that is made up of calcium carbonate and magnesium carbonate as well as other essential minerals. Because of this, it's sometimes used in dietary supplements. Check with your doctor before using dolomite to make sure it would be safe for you.
Dolomite is a source of calcium, which you need for nerve and muscle function and for keeping your bones and teeth strong. If you don't get enough calcium, you're more likely to develop osteoporosis as you get older. Dolomite consists of approximately 54 percent calcium -- so there's roughly 540 milligrams of calcium per gram of dolomite. Adults need about 1,000 milligrams of calcium but less than 2,500 milligrams per day for optimal health. You can also get calcium from foods, including green leafy vegetables, dairy products, canned salmon or sardines and fortified foods and beverages. Getting too much calcium could increase your risk for kidney stones and constipation.
Dolomite consists of approximately 46 percent magnesium, or 460 milligrams of magnesium per gram of dolomite. You need magnesium for forming bones, protein and DNA, as well as for regulating your blood sugar and blood pressure levels and proper nerve and muscle function. Women should consume at least 320 milligrams per day, and men need at least 420 milligrams. Other sources of magnesium include almonds, cashews, peanuts, spinach, black beans, edamame, fortified cereals, whole-wheat bread and yogurt.
Don't consume more than 350 milligrams of magnesium per day from supplements, as this could cause toxicity symptoms, including nausea, diarrhea, abdominal cramps, depression, irregular heartbeat, low blood pressure and difficulty breathing.
The type of calcium found in dolomite, calcium carbonate, isn't as easy for your body to break down and absorb as some other types of calcium, including calcium citrate. You need to have plenty of stomach acid to use calcium carbonate, so it's best to take it with food. As with any calcium supplement, spread your dose throughout the day so you're not taking more than 500 milligrams at a time to increase absorption.
Dolomite can sometimes be contaminated with high amounts of lead, barium, mercury and other toxic chemicals. If you take supplements containing dolomite, choose those with the United States Pharmacopeia symbol on the label, as these have to be tested to ensure they don't contain contaminants above certain levels.