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Calcium Supplement Side Effects

Calcium supplement side effects can be classified calcium-supplement-side-effects | Articlebased on reactions to certain forms of calcium, interactions with medicines and complications due to taking too much of the mineral.

According to the Food & Drug Administration’s (FDA), calcium Fact Sheet, hypercalcemia is an acute example of calcium supplement side effects:

“Excessively high levels of calcium in the blood known as hypercalcemia impair kidney function, and lead to reduced absorption of other essential minerals, such as iron, zinc, magnesium, and phosphorus. However, hypercalcemia rarely results from dietary or supplemental calcium intake and is most commonly associated with hyperparathyroidism, advanced cases of cancer or excessive intakes of vitamin D from supplements at doses of 50,000 IU/day or higher."

Tolerable Upper Intake Levels (ULs) for Calcium are:

Age Male Female Pregnant Lactating
Birth to 12 Months None Established None Established    
1-13 years 2,500 mg 2,500 mg    
14-50 years 2,500 mg 2,500 mg 2,500 mg 2,500 mg
51+ years 2,500 mg 2,500 mg    


The Fact Sheet also lists compounds that can be impaired by calcium intake or that can cause calcium supplement side effects.

“Calcium can decrease the absorption of the following drugs when taken together: bisphosphonates, the fluoroquinolone and tetracycline classes of antibiotics, levothyroxine, phenytoin (an anticonvulsant), and tiludronate disodium (to treat Paget's disease).

Thiazide-type diuretics can interact with calcium carbonate and vitamin D supplements, increasing the risks of hypercalcemia and hypercalciuria.  Both aluminum- and magnesium-containing antacids increase urinary calcium excretion. Mineral oil and stimulant laxatives decrease calcium absorption. Glucocorticoids, such as prednisone, can cause calcium depletion... when they are used for months.”

The National Institutes of Health (http://www.niams.nih.gov/health_info/bone/bone_health/nutrition/calcium_supp.asp) notes that calcium supplement side effects include interfering with iron absorption. Avoid taking both at the same time. Or to reduce the concern, take calcium citrate or vitamin C with iron.    Finally, the NIH notes that:” [a]ny medications that need to be taken on an empty stomach should not be taken with calcium supplements.”

In its calcium supplement side effects section, WebMD notes that:

“Calcium is LIKELY SAFE for most people when taken appropriately and in amounts under 2500 mg. Calcium [carbonate] can cause some minor side effects such as belching or gas. Taking too much calcium (over 2500 mg/day) might increase the risk of side effects.

Pregnancy and breast-feeding: Calcium is LIKELY SAFE when used in recommended amounts during pregnancy and breast-feeding."

WebMD states that high levels of phosphate in the blood (hyperphosphatemia) or low levels of phosphate in the blood (hypophosphatemia) can be a problem “Calcium and phosphate have to be in balance in the body. Taking too much calcium can throw this balance off and cause harm.”  Similarly, “[c]alcium can interfere with thyroid hormone replacement treatment. Separate calcium and thyroid medications by at least 4 hours. Finally, calcium should be avoided if you have too much calcium in the blood (as in parathyroid gland disorders and sarcoidosis).

calcium-supplement-side-effects | ArticleCalcium is regarded as a safe and essential mineral in human health.  Your physician can provide guidance on your particular intake level to protect your bones while limiting the risk or complications from calcium supplement side effects.