The Side Effects of Calcium Caltrate vs. Calcium Citrate

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Your body needs calcium for strong bones and proper functioning of the nerves, heart and muscles. Calcium is so important to the body that many people need to take supplements, especially as they get older. Calcium supplements come in two main forms: calcium citrate and calcium carbonate. Caltrate is a brand of calcium carbonate.

Calcium Supplements

You may not be getting enough calcium for bone health. Nutrient malabsorption of minerals such as calcium can also occur with Crohn’s disease, or after surgical procedures on the intestines. If you are a postmenopausal woman and you drink a lot of caffeine-containing beverages, alcohol or soft drinks, or take medications such as corticosteroids, you may need a supplement. Ask your doctor if you need calcium supplements and for a recommendation on the type you should take.

Serious Side Effects

Like all medications, calcium supplements can have side effects. The most serious of these, for both Caltrate and calcium citrate, is a serious allergic reaction. The symptoms of an allergy include a rash, hives, difficulty breathing and swelling of the mouth, face or tongue. A severe allergic reaction can be life-threatening, and you should immediately seek medical attention.

Caltrate Side Effects

Caltrate can cause rebound hyperacidity, a condition in which the stomach produces excess acid. Other gastrointestinal effects include constipation and gallstones. If you take large amounts of Caltrate over a period of time you can develop a condition called milk alkali syndrome. Milk alkali syndrome sufferers will have alkalosis -- too little acid in the body -- high serum calcium and renal insufficiency.

Hypercalemia, Kidney Damage and Phosphate

Some people who take Caltrate, or other calcium carbonate supplements, have developed high levels of calcium in the blood, a condition called hypercalcemia. This side effect seems to be more common in people who have kidney problems, such as those with kidney failure. It can cause irreversible kidney damage and renal failure. Phosphate, another mineral in the body, can also get too high if you take large amounts of calcium carbonate or Caltrate over time.

Calcium Citrate and Other Side Effects

In contrast to Caltrate, calcium citrate has few side effects. Other than the potential for allergic reaction, the most common side effects from calcium citrate are constipation and headache. However, calcium in any form can interact with other medications and high doses can cause gastrointestinal upset. Consult a health care professional if you have questions or concerns about taking calcium supplements.