Calcium is the most plentiful mineral in your body. You need a steady supply of dietary calcium to support bone growth and strength, and normal muscle, nerve and heart function. As important as calcium is to your health, consuming too much may cause medical problems. Although calcium deficiency is a much more common problem than excess intake, it is important not to get overzealous and consume potentially dangerous levels of calcium.
Tolerable Upper Intake
The Institute of Medicine has established safe upper limits for daily calcium intake. From age 18 through 50, your daily calcium intake should not exceed 2,500 mg. If you are older than age 50, limit your daily calcium intake to 2,000 mg. These limits were established because consuming more than these amounts over time has been associated with potentially serious health problems. You are most likely to exceed safe daily limits if you are consuming calcium supplements along with a calcium-rich diet.
Signs and Symptoms of Hypercalcemia
Excess calcium consumption may cause an abnormal elevation in your blood calcium level, a condition known as hypercalcemia. Signs and symptoms do not usually develop until your blood calcium level is markedly elevated. You may experience muscle weakness and digestive system symptoms, including loss of appetite, constipation, abdominal pain, nausea and vomiting. Brain-related signs and symptoms may also develop with calcium overload, including confusion, reduced consciousness, emotional instability and losing touch with reality. Severe hypercalcemia may lead to coma.
Urinary System Stones
Hormones from your thyroid and parathyroid glands and vitamin D regulate your blood calcium level. If you consume more calcium than you need, the excess is excreted in your urine. High concentrations of urinary calcium may lead to the formation of stones in your kidneys or bladder. If your diet is also high in protein and salt, your risk of urinary stones may be further increased. At the very least, having a kidney or bladder stone is profoundly painful. In complicated cases, an infection or blockage of your urinary system may be potentially life threatening. Your kidneys may be permanently scarred by complicated kidney or bladder stones.
Healthful Dietary Calcium
Now that you know the potential dangers of excess calcium in your diet, it's important to develop a nutritional plan that ensures you're taking in an adequate amount without overdoing it. Good sources of calcium include milk and dairy products, fortified cereals and juices, salmon, sardines, greens, spinach, okra and kale. If you're eating a well-balanced diet, including the recommended servings from each of the major food groups, you are likely to get all the calcium you need without risking possible overload.
References
- "What We Eat in America, NHANES 2005--2006: Usual Nutrient Intakes from Food and Water Compared to 1997 Dietary Reference Intakes for Vitamin D, Calcium, Phosphorus and Magnesium"; USDA Agricultural Research Service; July 2009
- "Dietary Reference Intakes for Calcium and Vitamin D"; Report Brief; Food and Nutrition Board of the Institute of Medicine of the National Academies; 2011
- "Dietary Reference Intakes for Calcium and Vitamin D"; Tolerable Upper Intake Levels: Calcium and Vitamin D; Food and Nutrition Board of the Institute of Medicine of the National Academies; 2011
- "The Merck Manual for Healthcare Professionals"; Disorders of Calcium Concentration; James L. Lewis, III, M.D.; May 2009
- Endotext.com; Calcium and Phosphate Homeostasis; Leonard J. Deftos, M.D., J.D.; May 2010
- National Institutes of Health, Office of Dietary Supplements: Calcium
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