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Calcium

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Related terms
Background
Evidencetable
Tradition
Dosing
Safety
Interactions
Attribution
Bibliography

Related Terms
  • AdvaCAL®, Alka-Mints®, Apo-Cal®, atomic number 20, Bica®, Bo-Ne-Ca®, bone meal, bovine cartilage, Ca, Cal-100®, Calcanate®, Calcefor®, Calci Aid®, Calci-Fresh®, Calcigamma®, Calcilos®, Calcimax®, Calcit®, calcitonin, Calcitridin®, calcitriol, calcium acetate, calcium aspartate, calcium carbonate, calcium chelate, calcium chloride, calcium citrate, calcium citrate malate, Calcium Dago® (Germany), calcium formate, calcium glucepate, calcium gluconate, Calcium Klopfer® (Austria), calcium lactate, calcium lactate gluconate, calcium lactogluconate, calcium orotate, calcium oxalate, Calcium Pharmavit® (Hungary), calcium phosphate, calcium pyruvate, Calcium-Sandoz Forte® (Bulgaria), Calcuren® (Finland), Caldoral® (Colombia), Calmate® 500 (Philippines), CalMax®, Calmicid®, Cal-Quick®, Calsan® (Mexico, Peru, Philippines), Calsup®, Cal-Sup® (New Zealand), Caltab® (Thailand), Caltrate®, Caltrate® (Colombia, Malaysia, Mexico, Puerto Rico, South Africa), Caltrate 600® (Canada, Colombia, Costa Rica, Dominican Republic, Ecuador, El Salvador, Guatemala, Honduras, Nicaragua, Panama, Peru, Venezuela), Cantacid® (Korea), Cartilade®, CC-Nefro 500® (Germany), Chooz®, Chooz Antacid Gum 500® (Israel), Citrical®, coral calcium, dairy products (milk, cheese, yogurt, etc.), dicalcium phosphate, Dimacid®, dolomite, Estroven®, Fixical® (France), Gaviscon®, heated oyster shell-seaweed calcium, hydroxyapatite, intravenous 42Ca, isotopically enriched milk, LeanBalance®, Living Calcium®, Maalox®, Maalox® Quick Dissolve (Canada), magnesium, Netra® (Israel), Neutralin®, Noacid® (Uruguay), nonfat milk, oral 44Ca,Orocal® (France), Os-Cal®, Ospur® Ca 500 (Germany), Osteocal® 500 (France), osteocalcin, Osteomin® (Mexico), OsteoPrime®, Osteo Wisdom®, oyster shell calcium, oyster shell electrolysate (OSE), Pepcid® Complete, Pluscal® (Argentina), Posture-D®, Renacal (Germany), Rocaltrol®, Rolaids®, salmon calcitonin, Sandocal®, shark cartilage, tricalcium phosphate, Tums®, Tums Ultra Assorted Berries® (Israel), Tums Ultra Spearmint® (Israel), Tzarevet X® (Israel), Viactiv®.

Background
  • The Romans used lime (calcium oxide), clacked lime (calcium hydroxide), and hydraulic cement in construction works. Calcium (Latin calx, meaning "lime") was first isolated in its metallic form by Sir Humphrey Davy in 1808 through the electrolysis of a mixture of calcium oxide and mercury oxide.
  • Chelated calcium refers to the way in which calcium is chemically combined with another substance. Calcium citrate is an example of such a chelated preparation. Calcium may also be combined with other substances to form preparations such as calcium lactate or calcium gluconate. Calcium carbonate may be refined from limestone, natural elements of the earth, or from shell sources, such as oyster. Shell sources are often described on the label as a "natural" source. Calcium carbonate from oyster shells is not "refined" and may contain variable amounts of lead.
  • Calcium is the most abundant mineral in the human body and has several important functions. More than 99% of total body calcium is stored in the bones and teeth where it supports the structure. The remaining 1% is found throughout the body in blood, muscle, and the intracellular fluid. Calcium is needed for muscle contraction, blood vessel constriction and relaxation, the secretion of hormones and enzymes, and nervous system signaling. A constant level of calcium is maintained in body fluid and tissues so that these vital body processes function efficiently.
  • The body gets the calcium it needs in two ways. One method is dietary intake of calcium-rich foods including dairy products, which have the highest concentration per serving of highly absorbable calcium, and dark, leafy greens or dried beans, which have varying amounts of absorbable calcium. Calcium is an essential nutrient required in substantial amounts, but many diets are deficient in calcium.
  • The other way the body obtains calcium is by extracting it from bones. This happens when blood levels of calcium drop too low and dietary calcium is not sufficient. Ideally, the calcium that is taken from the bones will be replaced when calcium levels are replenished. However, simply eating more calcium-rich foods does not necessarily replace lost bone calcium, which leads to weakened bone structure.
  • Hypocalcemia is defined as a low level of calcium in the blood. Symptoms of this condition include sensations of tingling, numbness, and muscle twitches. In severe cases, tetany (muscle spasms) may occur. Hypocalcemia is more likely to be due to a hormonal imbalance, which regulates calcium levels, rather than a dietary deficiency. Excess calcium in the blood may cause nausea, vomiting, and calcium deposition in the heart and kidneys. This usually results from excessive doses of vitamin D and may be fatal in infants.
  • The Surgeon General's 2004 report "Bone Health and Osteoporosis" stated that calcium has been singled out as a major public health concern today because it is critically important to bone health, and the average American consumes levels of calcium that are far below the amount suggested. Vitamin D is important for good bone health because it aids in the absorption and utilization of calcium. There is a high prevalence of vitamin D insufficiency in nursing home residents, hospitalized patients, and adults with hip fractures.
  • Calcium supplements are widely used to reduce bone resorption in osteoporosis, and many studies support this use. Calcium supplementation is also used as an antacid, for building bone mineral density, for hyperphosphatemia, hypocalcemia, renal failure, magnesium toxicity, black widow spider bite, fracture prevention, gastrointestinal tract and colorectal cancer prevention, hyperkalemia, hypertension, lead toxicity, osteomalacia (bone softening)/rickets, postsurgical side effects (rectal epithelial hyperproliferation), preeclampsia, premenstrual syndrome (PMS), seizures, arrhythmias, bone diseases, breast cancer prevention, cardiovascular risk reduction, cystic fibrosis, endometrial cancer prevention, fall prevention, growth, childbirth (preterm birth prevention), circulation, hyperparathyroidism, mortality, muscle strength, myocardial infarction, osteoporosis (drug-induced), ovarian cancer prevention, postnatal depression, type 2 diabetes, weight loss, cardiopulmonary resuscitation (CPR), and vaginal disorders. Calcium's use for calcium channel blocker overdose is investigational.

Evidence Table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *


Calcium carbonate is an U.S. Food and Drug Administration (FDA) approved over-the-counter (OTC) drug used to treat gastric hyperacidity (high acid levels in the stomach).

A


Multiple studies of calcium supplementation have found that high calcium intakes may help reduce the loss of bone density. Studies indicated that bone loss could be prevented in many areas including ankles, hips, and spine.

A


Hyperphosphatemia (high phosphate level in the blood) is associated with increased cardiovascular mortality in adult dialysis patients. Calcium carbonate or acetate may be used effectively as phosphate binders. Use may increase calcium-phosphate products in blood. Treatment of high blood phosphorous levels should only be done under supervision of a qualified healthcare professional.

A


Calcium supplementation is used to treat conditions arising from calcium deficiencies such as hypocalcemic (low blood calcium) tetany (muscle spasms), hypocalcemia related to hypoparathyroidism (low levels of the parathyroid hormone), and hypocalcemia due to rapid growth or pregnancy. It is also used for the treatment of hypocalcemia for conditions requiring a prompt increase in plasma calcium levels (e.g., tetany in newborns and tetany due to parathyroid deficiency, vitamin D deficiency, and alkalosis) and for the prevention of hypocalcemia during exchange transfusions. Treatment of hypocalcemia should only be done under supervision of a qualified healthcare professional.

A


Tetany is a condition of prolonged and painful spasms of the voluntary muscles, especially the fingers and toes (carpopedal spasm) as well as the facial musculature. Hypocalcemic tetany may be brought about by a calcium deficiency. Intravenous calcium has been used to treat hypocalcemia.

A


Osteoporosis is a disorder of the skeleton in which bone strength is reduced, resulting in an increased risk of fracture. Although osteoporosis is most commonly diagnosed in white postmenopausal women, women of other racial groups and ages, men, and children may also develop osteoporosis.

Calcium is the nutrient consistently found to be the most important for attaining peak bone mass and preventing osteoporosis. Adequate vitamin D intake is required for optimal calcium absorption. Adequate calcium and vitamin D are deemed essential for the prevention of osteoporosis in general, including postmenopausal osteoporosis.

Although calcium and vitamin D alone are not suggested as the sole treatment of osteoporosis, they are necessary additions to pharmaceutical treatments. The vast majority of clinical trials investigating the efficacy of pharmaceutical treatments for osteoporosis have investigated these agents in combination with calcium and vitamin D. So, although calcium alone is unlikely to have an effect on the rate of bone loss following menopause, osteoporosis may not be treated in the absence of calcium. Treatment of postmenopausal osteoporosis should only be done under supervision of a qualified healthcare professional.

A


Kidney disease occurs when the kidneys permanently lose the ability to remove waste and maintain fluid and chemical imbalances in the body. Kidney disease may develop rapidly (over two to three months) or very slowly (over 30 to 40 years). The effectiveness of calcium salts vs. sevelamer in peritoneal dialysis has been reviewed. According to secondary sources, calcium carbonate or calcium acetate is equally effective as a phosphate binder for renal failure. Calcium citrate, however, increases absorption of aluminum, and is therefore not suggested for renal failure treatment.

A


Intravenous calcium is used in the treatment of hypermagnesemia (high levels of magnesium in the blood). Case studies suggest intravenous calcium may aid in the improvement of symptoms. Treatment of magnesium toxicity should only be done under supervision of a qualified healthcare professional.

A


Calcium supplementation is used in the treatment of black widow spider bites to relieve muscle cramping in combination with antiserum, analgesics (pain relievers), and muscle relaxants. Treatment of a black widow spider bite should only be done under the supervision of a qualified healthcare professional.

B


A fracture is a break in a bone or cartilage, often but not always the result of trauma. Calcium supplementation may be effective in preventing fractures through the prevention of bone loss. Further studies are needed to validate these results.

B


Colorectal cancer is the most common gastrointestinal cancer and the second leading cause of cancer deaths in the United States. Colorectal cancer is caused by a combination of genetic and environmental factors, but the degree to which these two factors influence the risk of colon cancer in individuals varies. Most large prospective studies have found increased calcium intake to be only weakly associated with a decreased risk of colorectal cancer. Further studies are needed to verify these results. Treatment of colorectal cancer should only be done under the supervision of a qualified healthcare professional.

B


Calcium supplementation may aid in antagonizing the cardiac toxicity and arrhythmia (abnormal heart rhythm) associated with hyperkalemia (high blood potassium), provided the patient is not receiving digitalis drug therapy. Treatment of hyperkalemia should only be done under supervision of a qualified healthcare professional.

B


Several studies have found that introducing calcium to the system may have hypotensive (blood pressure lowering) effects. These studies indicate that high calcium levels lead to sodium loss in the urine, and lowered parathyroid hormone (PTH) levels, both of which result in the lowering of blood pressure. However, one study found that these results did not hold true for middle-aged patients with mild to moderate essential hypertension.

In the DASH (Dietary Approaches to Stop Hypertension) study, three servings daily of calcium enriched low-fat dairy products reduced systolic and diastolic blood pressure. This research indicates that a calcium intake at the suggested level may be helpful in preventing and treating moderate hypertension. Treatment of high blood pressure should only be done under supervision of a qualified healthcare professional.

B


A chelating treatment of calcium has been suggested to reduce blood levels of lead in cases of lead toxicity. Reduced symptoms have been observed in most, but not all, patient case reports and case histories. Adequate calcium intake appears to be protective against lead toxicity. Treatment of lead toxicity should only be done under the supervision of a qualified healthcare professional.

B


For the general population, meeting current suggestions for calcium intake during pregnancy may help prevent pregnancy-induced high blood pressure (PIH). Further research is required to determine whether women at high risk for PIH would benefit from calcium supplementation above the current recommendations. However, studies have failed to demonstrate an effect of calcium supplementation on the development of preeclampsia. Treatment of PIH should only be done under supervision of a qualified healthcare professional.

B


There is a link between lower dietary intake of calcium and symptoms of premenstrual syndrome. Calcium supplementation has been suggested in various clinical trials to decrease overall symptoms associated with PMS, such as depressed mood, water retention, and pain.

B


Seizures are caused by uncontrolled electrical activity in the brain, which may produce a physical convulsion, minor physical signs, thought disturbances, or a combination of symptoms. According to case reports, nutritional deficiencies, including low levels of calcium may lead to changes in the electrical patterns of the brain and may increase the risk of seizures. Correcting calcium to normal levels in cases of hypocalcemia may be necessary. Further study is warranted.

B


An arrhythmia is an abnormal heart rhythm. The heart rhythm may be too fast (tachycardia), too slow (bradycardia), or irregular. Some arrhythmias, such as ventricular fibrillation, may lead to cardiac arrest if not treated promptly. According to anecdote and animal data, intravenous calcium has been suggested as a treatment for arrhythmias. Anecdote suggests, however, that in persons with heart diseases, injected calcium may increase the risk of irregular heartbeats. Clinical trials are warranted.

C


Rickets and osteomalacia (bone softening) are commonly thought of as diseases due to vitamin D deficiency; however, calcium deficiency may also be another cause in sunny areas of the world where vitamin D deficiency would not be expected. Calcium supplementation is used as an adjuvant in the treatment of rickets and osteomalacia, as well as a single therapeutic agent in nonvitamin D-deficient rickets. Research continues into to the importance of calcium alone in the treatment and prevention of rickets and osteomalacia. Treatment of rickets and osteomalacia should only be done under the supervision of a qualified healthcare professional.

C


Calcium supplementation in patients on long-term, high-dose inhaled steroids for asthma may reduce bone loss due to steroid intake. Treatment using the prescription drug pamidronate with calcium has been shown to be superior to calcium alone in the prevention of corticosteroid-induced osteoporosis. Inhaled steroids have been reported to disturb normal bone metabolism, and they are associated with a decrease in bone mineral density. Results suggest that long-term administration of high-dose inhaled steroid induces bone loss that is preventable with calcium supplementation with or without the prescription drug etidronate. Long-term studies involving more patients should follow to confirm these preliminary findings.

C


Some studies have linked higher calcium and vitamin D intake with lower breast cancer risk. Further studies are needed. Treatment of breast cancer should only be done under the supervision of a qualified healthcare professional.

C


A review of the effects of calcium on myocardial infarction and cardiovascular events suggested a statistically nonsignificant increased risk for stroke, and a statistically significant increased risk for myocardial infarction with calcium use. Other researchers, however, have pointed out multiple flaws with this review and that more evidence is needed. A prospective analysis of the effects of calcium supplementation in postmenopausal women in Finland appeared to increase the risk of coronary heart disease (CHD). A pooled analysis of cohort studies suggested a lack of increased risk of stroke with consumption of milk products.

C


Preterm birth is defined as a delivery that occurs prior to 37 completed weeks. It is a chief cause of perinatal mortality and morbidity around the world. Calcium supplementation has been suggested as a means of prevention of preterm birth.

C


Circulation is defined as the course of the blood from the heart through the arteries, capillaries, and veins back again to the heart. Normalization of priming solution ionized calcium concentration improved the hemodynamic stability of neonates receiving venovenous extracorporeal membrane oxygenation (ECMO). Further study is needed in order to draw a firm conclusion.

C


Cystic fibrosis (CF) is a genetic disease characterized by the production of abnormal secretions, leading to the accumulation of mucus in the lungs, pancreas, and intestine. This build-up of mucus causes difficulty breathing and recurrent lung infections, as well as problems with nutrient absorption due to problems in the pancreas and intestines. Without treatment, CF results in death for 95% of affected children before age five; however, the longest-lived CF patient survived into his late 30s. Human studies have been conducted examining the role of calcium and vitamin D supplementation in subjects with CF. Further study is needed before a firm conclusion may be made.

C


According to a meta-analysis of epidemiological evidence, a statistically nonsignificant, inverse association between endometrial cancer and calcium intake has been noted. Further study is needed in order to draw a more firm conclusion about the utility of calcium in decreasing endometrial cancer risk.

C


The utility of calcium in the prevention of falls, particularly in elderly populations, has been examined. Frequently calcium is used in combination with vitamin D. Further studies may be warranted.

C


Growth of very low birth weight infants correlates with calcium intake and retention in the body. It is possible that human milk fortifiers commonly used may have inadequate levels of calcium for infants of very low birth weight. Bone mineralization is also lower in very low birth weight infants at theoretical term than in infants born at term. Use of a formula containing higher levels of calcium has been suggested to allow improved bone mineralization in these infants. One study has looked at the effects of milk supplementation in young girls with low dietary calcium intake and found that after two years, increases in bone density could be observed mainly in the legs. More studies are needed before a conclusion may be made.

C


In patients on hemodialysis, calcium supplementation may reduce secondary hyperparathyroidism (high blood levels of parathyroid hormone due to another medical condition or treatment). Treatment of hyperparathyroidism should only be done under the supervision of a qualified healthcare professional.

C


The effects of calcium on mortality have been studied in various populations, including perinatal populations. The effects of vitamin D and calcium have also been studied. Although the effects of calcium on maternal mortality seem to be promising, further study is needed before a firm conclusion may be drawn.

C


The effects of calcium on muscle strength are unclear. The available evidence is derived from combination studies; the effect of calcium alone is unclear. Further study is needed before a firm conclusion may be drawn.

C


The evidence for the effects of calcium on myocardial infarction is mixed. One review of the effects of calcium on myocardial infarction and cardiovascular events suggested a statistically significant increased risk for myocardial infarction with calcium use. Other researchers, however, have pointed out multiple flaws with this review, and that more evidence is needed.

C



Calcium phosphate has been used in the treatment and prevention of oral mucositis. Further study is needed.

C


Rickets and osteomalacia (bone softening) are commonly thought of as diseases due to vitamin D deficiency; however, calcium deficiency may also be another cause in sunny areas of the world where vitamin D deficiency would not be expected. Calcium is used as an adjuvant in the treatment of rickets and osteomalacia. Research continues into the importance of calcium alone in the treatment and prevention of rickets and osteomalacia. Treatment of rickets and osteomalacia should only be carried out under the supervision of a qualified healthcare professional.

C


A meta-analysis of case-control studies examining the effects of dairy products and calcium on ovarian cancer risk found a lack of increased risk with dairy consumption. The analysis, however, did observe an increased risk for ovarian cancer with a lactose intake equal to three or more daily servings of milk. A nested case-control study found a statistically significant, inverse relationship between ovarian cancer risk and calcium intake. Further study is needed before a firm conclusion may be drawn.

C


Calcium has been suggested as a treatment for postnatal depression (PND) in humans. Further data, however, are lacking. Future research for PND prevention is warranted.

C


Following intestinal bypass surgery, fecal bile acids and fatty acids tend to increase, which may contribute to proliferative effects. In humans, calcium inhibited the proliferative effects, and reversed postsurgical proliferative changes. Further studies are needed in order to make a firm conclusion.

C


In clinical study, combining vitamin D with calcium demonstrated a reduced risk of type 2 diabetes, with the highest intake resulting in a 33% decreased risk. For interventional trials, in hypertensive nondiabetics, compared to placebo, 1,500 milligrams daily of calcium for eight weeks improved insulin sensitivity. While promising, further trials are warranted.

C


Diets with higher calcium density (high levels of calcium per total calories) have been associated with a reduced incidence of being overweight or obese in several studies. While more research is needed to understand the relationships between calcium intake and body fat, these findings emphasize the importance of maintaining an adequate calcium intake while attempting to diet or lose weight.

C

Cardiopulmonary resuscitation is the restoration of cardiac output and pulmonary ventilation following cardiac arrest and apnea, using artificial respiration and manual closed-chest compression or open-chest cardiac massage. Per the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science, routine administration of calcium for the treatment of cardiac arrest is no longer advised. Variable results have been observed in trials, and a beneficial effect on survival is lacking with the use of calcium.

D


Stopping treatment with topical hormone replacement therapy and switching to treatment with calcium plus vitamin D made vaginal atrophy worse in one study. Increases in painful or difficult intercourse and urinary leaks were reported. Menopausal complaints of hot flashes and night sweats were also worse than before calcium plus vitamin D therapy.

D
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)


Tradition / Theory

The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.

  • Astrocytic glioma, bone density improvement (lactating women), carcinoma, cardiac arrest, dental hygiene, diarrhea, disease diagnosis (Zollinger-Ellison), female urinary incontinence, high cholesterol, intestinal disorders, ischemic stroke (prevention), leg cramps (pregnancy), medullary thyroid cancer (diagnosis), multiple sclerosis, neuromuscular blockade (antagonize), psoriasis, reducing fluoride levels (children), yellow oleander poisoning.

Dosing

General

  • A good food source of calcium contains a substantial amount of calcium in relation to its calorie content and contributes at least 10% of the U.S. Recommended Dietary Allowance (RDA) for calcium in a selected serving size. The RDA for elemental calcium is 1,000 milligrams daily for adults (except pregnant or lactating women) and children over four years of age. Adequate intake (AI) recommendations published in August 1997 were set at 1,000 milligrams for men and women aged 19-50, and 1,200 milligrams for individuals older than age 70 and in postmenopausal women.
  • The dose, frequency, and duration of calcium gluconate used for any indication are dependent on individual requirements. Doses ranging from 200-3,500 milligrams daily of oral calcium have been used in several studies. Note that there are many forms available; calcium sources included calcium carbonate, calcium citrate malate, calcium lactate gluconate, calcium phosphate milk extract, calcium phosphate, or milk minerals. Different conditions may require unique dosing and should be discussed with a qualified healthcare provider. Intravenous calcium may be given by a qualified healthcare provider.

Adults (over 18 years old)

  • The dose, frequency, and duration of calcium used for any indication are dependent on individual requirements. The following amounts have been suggested for daily elemental calcium intake: 1,000 milligrams (19-50 years), 1,000 milligrams (51-70 years), and 1,200 milligrams (postmenopausal women or 71+ years). In human study, oral calcium doses typically range from 200-3,500 milligrams daily. Many forms are available. Different conditions may require unique dosing and should be discussed with a qualified healthcare provider.
  • The dose, frequency, and duration of calcium gluconate used for any indication are dependent on individual requirements. According to the National Institutes of Health, the usual adult dose of calcium gluconate ranges from 5-20 milliliters given intravenously either directly or by infusion.
  • Oral calcium phosphate has been used for oral mucositis (mouth ulcers/irritation).

Children (under 18 years old)

  • The dose, frequency, and duration of calcium gluconate used for any indication is dependent on individual requirements. The following amounts have been suggested for daily calcium intake: 200 milligrams (0-6 months), 260 milligrams (7-12 months), 700 milligrams (1-3 years), 1,000 milligrams (4-8 years), 1,300 milligrams (9-13 years), and 1,300 milligrams (14-18 years). Special dosing may be suggested by a qualified healthcare provider for certain indications. In very low birth weight infants, high calcium diets may require greater phosphorus intake, with an optimal calcium:phosphorus mass ratio of 1.6:1 to 1.8:1.
  • The daily tolerable upper intake level (UL) by age is 0-6 months, 1,000 milligrams; 6-12 months, 1,500 milligrams; 1-3 years, 2,500 milligrams; 9-18 years, 3,000 milligrams; 19-50 years, 2,500 milligrams; 51+ years, 2,000 milligrams.
  • The dose, frequency, and duration of calcium gluconate used for any indication is dependent on individual requirements. According to the National Institutes of Health, the usual dose of calcium gluconate in children ranges from 2-5 milliliters given intravenously either directly or by infusion. For infants, the dose is not to exceed 2 milliliters.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

  • Avoid in individuals with a known allergy/hypersensitivity to calcium supplements or any of their ingredients. Dairy products contain lactose and dairy products are a common food source of calcium, but some people are lactose intolerant. Lactose intolerance may cause cramping, bloating, gas, and diarrhea. Lactose intolerance affects the population in varying degrees.
  • Avoid calcium supplementation in those who are very sensitive to any component of a calcium-containing supplement, or who have hypercalcemia (high levels of calcium in the blood). Conditions causing hypercalcemia include sarcoidosis (inflammation in the lymph nodes and other organs), hyperparathyroidism (high levels of parathyroid hormone), and hypervitaminosis D (high levels of vitamin D).

Side Effects and Warnings

  • Calcium supplementation is likely safe when used orally and intravenously, as suggested by a qualified healthcare professional. It is also likely safe when used orally and appropriately in pregnancy and lactation, as suggested by a qualified healthcare professional. Routine dietary intake and supplementation in suggested doses are not associated with significant adverse effects.
  • Excretion of abnormally large amounts of calcium in the urine is a well-established side effect of administration.
  • Low levels of calcium in the blood and tissues may cause sensations of tingling, numbness, muscle twitches, and muscle spasms (tetany). This condition is more likely to be due to a hormonal imbalance in the regulation of calcium rather than a dietary deficiency.
  • Excess calcium in the blood may be without symptoms or it may cause loss of appetite, nausea, vomiting, constipation, abdominal pain, dry mouth, thirst, frequent urination, and calcium deposition in the heart and kidneys. More severe hypercalcemia may result in confusion, delirium, coma, and if not treated, death. Hypercalcemia has been reported only with the consumption of large quantities of calcium supplements usually in combination with antacids, particularly in the past when peptic ulcers were treated with large quantities of milk, calcium carbonate (antacid) and sodium bicarbonate (absorbable alkalai).
  • Use cautiously in those with achlorhydria (absence of hydrochloric acid or HCl in gastric juices) as low levels of gastric acid during digestion reduces urinary phosphate and calcium excretion. It may be advisable to take calcium carbonate with food to stimulate gastric acid production. Consult a qualified healthcare provider.
  • Use cautiously if taking large amounts of vitamin D. Excess calcium in the blood (hypercalcemia) may cause nausea, vomiting, and calcium deposition in the heart and kidneys. This usually results from excessive doses of vitamin D and may be fatal in infants. Consult a qualified healthcare provider.
  • Use cautiously when used with antiarrhythmics, antidiabetics, antihypertensives, antilipemics, bisphosphonates, calcium channel blockers, calcipotriene, Dovonex, tetracycline, fluoroquinolones, gentamicin, quinolones, diuretics, gadoversetamide, H2 antagonists, magnesium, inositol hexaphosphate, phytic acid, iron salts, lithium, Orlistat, Xenical®, oxalic acid, parathyroid agents, cinacalcet, potassium, sodium alginate, zinc, calcium carbonate and tribasic calcium phosphate tablets, large amounts of vitamin D, anticonvulsants, with aluminum- and magnesium-containing antacids, and in those with hypothyroidism or taking thyroxine, in postmenopausal women due to an increased possibility of cardiovascular side effects , and in those prone to the formation of calcium-containing kidney stones , and in patients with hyperphosphatemia or hypophosphatemia.
  • Use cautiously in individuals with heart arrhythmias and ventricular fibrillation (irregular heart beating). Large fluctuations in free calcium during intravenous calcium infusion may cause the heart to slow down or beat too rapidly. Although calcium appears to have benefits on bone density and osteoporosis, calcium should be used cautiously in postmenopausal women due to an increased possibility of cardiovascular side effects. Consult a qualified healthcare provider.
  • Avoid calcium supplements made from dolomite, oyster shells, or bone meal, because such compounds may contain unacceptable levels of lead.
  • Avoid high doses of calcium without food in those who are prone to the formation of calcium-containing kidney stones, as calcium supplementation in the absence of food may be associated with an increased risk of calcium oxalate stone formation. Consult a qualified healthcare professional if you are prone to kidney stones before using calcium supplements.
  • Avoid cigarette smoking, as this decreases intestinal calcium absorption and may lead to decreased bone mineral density.
  • Avoid in excess: the daily tolerable UL by age is 0-6 months, 1,000 milligrams; 6-12 months, 1,500 milligrams; 1-3 years, 2,500 milligrams; 9-18 years, 3,000 milligrams; 19-50 years, 2,500 milligrams; 51+ years, 2,000 milligrams. In patients using sodium polystyrene sulfonate; with digoxin (i.e., digitalis) toxicity or using digoxin. With hypercalcemia, hypercalciuria, hyperparathyroidism, bone tumors, and sarcoidosis; in chronic renal failure patients, especially in those taking aluminum-containing agents. In patients using ceftriaxone. Calcium supplements made from dolomite, oyster shells, or bone meal due to possible lead toxicity.

Pregnancy and Breastfeeding

  • The Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food, and Nutrition Board suggests that current calcium recommendations for nonpregnant women are also sufficient for pregnant women, because intestinal calcium absorption increases during pregnancy.
  • Pregnant women are especially vulnerable to accelerated bone turnover due to the physiologic stress of pregnancy and lactation. Studies indicate that pregnant women should take calcium supplements to prevent bone density loss. The National Academy of Sciences suggests that women who are pregnant or breastfeeding consume calcium each day. For pregnant teens, the suggested intake is higher.
  • Consult a qualified healthcare professional to determine dosing during pregnancy and breastfeeding.

Interactions

Interactions with Drugs

  • Intestinal aluminum absorption is increased in healthy and kidney failure patients taking even small amounts of calcium citrate. As a result, all citrate-containing preparations are contraindicated in chronic renal failure patients taking aluminum-containing compounds.
  • Seizure medications may decrease calcium absorption by increasing the metabolism of vitamin D. Taking seizure medications may lead to hypocalcemia (low blood calcium) and softening of the bones (osteomalacia).
  • Intake of a bisphosphonate and calcium may decrease the absorption of the bisphosphonate. Patients should take bisphosphonates at least 30 minutes before calcium. Optimally, the two would be consumed at different times of the day.
  • Caffeine may increase urinary calcium excretion and has been implicated in osteoporosis; however, research is still conflicting. Caffeine has a small effect on calcium absorption.
  • Calcitriol is a form of vitamin D that is used to treat and prevent low levels of calcium in the blood of patients whose kidneys or parathyroid glands (glands in the neck that release natural substances to control the amount of calcium in the blood) are not working normally.
  • When given intravenously, calcium may reverse the effects of calcium channel blockers (commonly used for high blood pressure). Calcium channel blockers include: nifedipine (Adalat®, Procardia®), verapamil (Calan®, Isopin®, Verelan®), diltiazem (Cardizem®), isradipine (DynaCirc®), felodipine (Plendil®), and amlodipine (Norvasc®).
  • Cholestyramine (commonly used for high cholesterol) may reduce the absorption of vitamin D, which, in turn, reduces the absorption of calcium.
  • Corticosteroids (commonly used for inflammation) may cause significant bone loss (osteoporosis) if the suggested level of calcium and vitamin D intake is not met.
  • Calcium levels should be monitored if taking the heart rhythm medication digoxin due to the potential for interaction with high blood levels of calcium and the need for adequate blood levels of calcium. Patients taking digoxin should consult with a qualified healthcare professional before using calcium supplements.
  • Alcohol may affect calcium status by reducing the intestinal absorption of calcium. It may also inhibit enzymes in the liver that help convert vitamin D to its active form, which in turn reduces calcium absorption. However, the amount of alcohol required to affect calcium absorption is unknown. Evidence is currently conflicting on whether moderate alcohol consumption is helpful or harmful to bone.
  • Fluroquinolone antibiotics form complexes with calcium in the gastrointestinal tract, which may lead to reduced absorption of both if taken at the same time.
  • Use of histamine-2 (H2) blockers (like ranitidine commonly used to treat acid reflux) at the same time as calcium carbonate or calcium phosphate may interfere with the absorption of these calcium salts.
  • Hormone replacement therapy (HRT) alone may be associated with a fall in calcium absorption efficiency. However, the bone-preserving effects of estrogen treatment are increased by calcium supplementation. Estrogen increases supplemental calcium absorption in postmenopausal women.
  • Use of inositol hexaphosphate (phytic acid) and calcium may decrease the absorption of calcium.
  • Mineral oil or stimulant laxatives (cascara, senna, and bisacodyl), when used for prolonged periods, may reduce dietary calcium and vitamin D absorption often causing osteomalacia (bone softening).
  • Intake of levothyroxine (synthroid, levothroid, levoxyl) at the same time as calcium carbonate has been found to reduce levothyroxine absorption and to increase serum thyrotropin levels. Levothyroxine may adsorb (stick) to calcium carbonate in an acidic environment, which may block its absorption.
  • Loop diuretics, including furosemide (Lasix®), bumetanide (Bumex®), ethracrynic acid (Edecrin®), and torsemide (Demadex®), at high doses, may reduce serum calcium levels because they increase urinary calcium excretion.
  • Orlistat (Xenical®, Alli®) has been shown to induce a relative increase in bone turnover (increased resorption or bone loss), which may be due to the malabsorption of vitamin D and/or calcium.
  • The effect of dietary phosphorus on calcium is minimal. Some researchers speculate that the detrimental effects of consuming foods high in phosphate such as carbonated soft drinks is due to the replacement of milk with soda rather than the phosphate level itself. Calcium may decrease the absorption of phosphate supplements.
  • Increasing dietary potassium intake in the presence of a low sodium diet may help decrease calcium excretion particularly in postmenopausal women.
  • Use of proton pump inhibitors (like esomeprazole used to treat ulcers) and calcium carbonate or calcium phosphate at the same time may cause decreased absorption of these calcium salts.
  • Typically, dietary sodium and protein increase calcium excretion as their intake is increased. However, if a high protein, high sodium food also contains calcium, this may help counteract the loss of calcium.
  • Calcium may form complexes with sotalol (a beta-blocker drug used to treat irregular heartbeats), reducing its absorption. A physician should be contacted in order to determine optimal timing of doses. Patients taking sotalol should consult a qualified healthcare professional before using calcium supplements.
  • Intake of a tetracycline antibiotic and calcium may decrease the absorption of the tetracycline, including doxycycline, minocycline, and tetracycline. Two to four hours between tetracyclines and calcium supplements should be allowed.
  • Thiazides are diuretics that reduce calcium excretion by the kidneys. These diuretics include: chlorothiazide (Diuril®), hydrochlorothiazide (HydroDIURIL®, Esidrix®), indapamide (Lozol®), metolazone (Zaroxolyn®), and chlorthalidone (Hygroton®).
  • Other agents with which calcium may interact: alendronate, antacids, anticoagulants, antidiabetics, antidotes, antihypertensives, calcium salts, ceftriaxone, dovonex, fluoride, gadoversetamide, gentamicin, heart rate-regulating agents, heavy metal antagonists/chelating agents, iron salts, lithium, magnesium, orlistat, oxalic acid, parathyroid agents, potassium salts, propionate, quinolones, and uronic acid.

Interactions with Herbs and Dietary Supplements

  • Calcium carbonate and aluminum hydroxide taken together have produced a significant rise in serum and urine aluminum levels.
  • Combined use of inositol hexaphosphate (phytic acid) and calcium may decrease the absorption of calcium.
  • Stimulant laxatives (cascara, senna, and bisacodyl) when used for prolonged periods may reduce dietary calcium and vitamin D absorption often causing osteomalacia (bone softening).
  • Combining calcium salts may increase absorption or alter efficacy.
  • Large doses of magnesium salts may cause hypocalcemia (low levels of blood calcium). Oral magnesium supplements do not affect calcium absorption.
  • Caffeine may increase urinary calcium excretion and has been implicated in osteoporosis; however, research is still conflicting. Caffeine has a small effect on calcium absorption.
  • Herbs with diuretic properties may reduce serum calcium levels by increasing urinary calcium excretion.
  • Herbs with estrogenic properties may increase supplemental calcium absorption in postmenopausal women.
  • Increasing dietary potassium intake in the presence of a low sodium diet may help decrease calcium excretion particularly in postmenopausal women.
  • Typically, dietary sodium and protein increase calcium excretion as their intake is increased. However, if a high protein, high sodium food also contains calcium, this may help counteract the loss of calcium.
  • Combined use of iron and calcium may not inhibit the absorption of iron over long periods of time. Combined use of fluoride, magnesium, or zinc and calcium may decrease the absorption of these minerals. However, these possible mineral interactions have not been shown to be of clinical significance.
  • Mineral oil may interfere with calcium utilization and retention by reducing the absorption of calcium and vitamin D.
  • Combined use of nondigestible fructo-oligosaccharides or inulin and calcium may increase the absorption of calcium in the colon.
  • Calcium taken orally may bind with phosphate in the gut, preventing its absorption and reducing the hyperphosphatemia (high levels of phosphate in the blood) associated with renal failure. Calcium carbonate or calcium acetate is used for this purpose, whereas calcium citrate is not suggested, because it increases aluminum absorption.
  • While the effects of high phosphorus intakes on calcium balance and bone health are presently unclear, the substitution of large quantities of soft drinks for milk or other sources of dietary calcium is cause for concern with respect to bone health in adolescents and adults. The effect of dietary phosphorus on calcium is minimal.
  • Reports show that increased sodium intake results in increased loss of calcium in the urine suggesting that an effect of reducing bone loss by increasing calcium supplementation may also be achieved by halving daily sodium excretion.
  • Intake of sodium alginate and calcium may decrease the absorption of calcium.
  • Excessive vitamin A use has also been found to alter bone turnover. Too much preformed vitamin A may promote fractures. Avoid vitamin supplements that have large amounts of vitamin A as preformed vitamin A, unless prescribed by a doctor. Vitamin A in the form of beta-carotene does not appear to increase one's fracture risk.
  • Use of vitamin D and calcium increases the absorption of calcium. Vitamin D is important and suggested for optimal calcium absorption.
  • Use cautiously with alcohol, antacids, antiarrhythmics, anticoagulants, anticonvulsants, antilipemics, digoxin, drynol cibotin, hypoglycemics, hypotensives, laxatives, oxalic acid, probiotics, soy, uronic acid.

Attribution
  • This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography
  1. Design of the Women's Health Initiative clinical trial and observational study. The Women's Health Initiative Study Group. Control Clin Trials 1998;19(1):61-109.
  2. NIH State-of-the-Science Conference Statement on Multivitamin/Mineral Supplements and Chronic Disease Prevention. NIH Consens.State Sci Statements. 5-15-2006;23(2):1-30.
  3. Bortolotti M, Rudelle S, Schneiter P, et al. Dairy calcium supplementation in overweight or obese persons: its effect on markers of fat metabolism. Am J Clin Nutr. 2008 Oct;88(4):877-85.
  4. Carrasco R, Lovell DJ, Giannini EH, et al. Biochemical markers of bone turnover associated with calcium supplementation in children with juvenile rheumatoid arthritis: results of a double-blind, placebo-controlled intervention trial. Arthritis Rheum. 2008 Dec;58(12):3932-40.
  5. Checa MA, Garrido A, Prat M, et al. A comparison of raloxifene and calcium plus vitamin D on vaginal atrophy after discontinuation of long-standing postmenopausal hormone therapy in osteoporotic women. A randomized, masked-evaluator, one-year, prospective study. Maturitas 9-16-2005;52(1):70-77.
  6. Day GM, Chance GW, Radde IC, et al. Growth and mineral metabolism in very low birth weight infants. II. Effects of calcium supplementation on growth and divalent cations. Pediatr Res 1975;9(7):568-575.
  7. Devine A, Dick IM, Heal SJ, et al. A 4-year follow-up study of the effects of calcium supplementation on bone density in elderly postmenopausal women. Osteoporos Int 1997;7(1):23-28.
  8. Domrongkitchaiporn S, Ongphiphadhanakul B, Stitchantrakul W, et al. Risk of calcium oxalate nephrolithiasis in postmenopausal women supplemented with calcium or combined calcium and estrogen. Maturitas 2-26-2002;41(2):149-156.
  9. Elders PJ, Lips P, Netelenbos JC, et al. Long-term effect of calcium supplementation on bone loss in perimenopausal women. J Bone Miner Res 1994;9(7):963-970.
  10. Hanzlik RP, Fowler SC, Fisher DH. Relative bioavailability of calcium from calcium formate, calcium citrate, and calcium carbonate. J Pharmacol Exp Ther 2005;313(3):1217-1222.
  11. Hofmeyr GJ, Mlokoti Z, Nikodem VC, et al. Calcium supplementation during pregnancy for preventing hypertensive disorders is not associated with changes in platelet count, urate, and urinary protein: a randomized control trial. Hypertens Pregnancy. 2008;27(3):299-304.
  12. Jorde R, Szumlas K, Haug E, et al. The effects of calcium supplementation to patients with primary hyperparathyroidism and a low calcium intake. Eur J Nutr 2002;41(6):258-263.
  13. Mazokopakis EE, Giannakopoulos TG, Starakis IK. Interaction between levothyroxine and calcium carbonate. Can Fam Physician 2008 Jan;54(1):39.
  14. McDonough RP, Doucette WR, Kumbera P, et al. An evaluation of managing and educating patients on the risk of glucocorticoid-induced osteoporosis. Value Health 2005;8(1):24-31.
  15. Reid I, Ames RW, Evans MC, et al. Effect of calcium supplementation on bone loss in postmenopausal women. N Engl J Med 2-18-1993;328(7):460-464.
  16. Thys-Jacobs S, Ceccarelli S, Bierman A, et al. Calcium supplementation in premenstrual syndrome: a randomized crossover trial. J Gen Intern Med 1989;4(3):183-189.

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The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.

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