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 can 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 can 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.
Hypocalcaemia 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. Hypocalcaemia is more likely to be due to a hormonal imbalance, which regulates calcium levels, rather than a dietary deficiency. Excess calcium in the blood can cause nausea, vomiting, and calcium deposition in the heart and kidneys. This usually results from excessive doses of vitamin D and can 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 recommended. 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 for colorectal neoplasia and in pregnancy.
Evidence
DISCLAIMER:
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.
Antacid (calcium carbonate):
Calcium carbonate is an FDA (U.S. Food and Drug Administration) approved over-the-counter (OTC) drug used to treat gastric hyperacidity (high acid levels in the stomach).
Grade: A
Bone loss (prevention):
Multiple studies of calcium supplementation in the elderly and postmenopausal women have found that high calcium intakes can help reduce the loss of bone density. Studies indicated that bone loss could be prevented in many areas including ankles, hips, and spine.
Grade: A
Cardiopulmonary resuscitation (CPR):
Calcium chloride may be given intravenously (IV) by a qualified healthcare professional in cardiac resuscitation, particularly after open-heart surgery, when epinephrine fails to improve weak or ineffective myocardial contractions. Calcium chloride is contraindicated for cardiac resuscitation in the presence of ventricular fibrillation. CPR with calcium chloride should only be done under the supervision of a qualified healthcare professional.
Grade: A
Deficiency (calcium):
Calcium gluconate is used to treat conditions arising from calcium deficiencies such as hypocalcaemic (low blood calcium) tetany (muscle spasms), hypocalcaemia related to hypoparathyroidism (low levels of the parathyroid hormone), and hypocalcaemia due to rapid growth or pregnancy. It is also used for the treatment of hypocalcaemia 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 hypocalcaemia during exchange transfusions. Treatment of hypocalcaemia should only be done under supervision of a qualified healthcare professional.
Grade: A
High blood phosphorous level:
Hyperphosphatemia (high phosphate level in the blood) is associated with increased cardiovascular mortality in adult dialysis patients. Calcium carbonate or acetate can 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.
Grade: A
Osteoporosis:
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 recommended 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 cannot be treated in the absence of calcium. Treatment of postmenopausal osteoporosis should only be done under supervision of a qualified healthcare professional.
Grade: A
Toxicity (magnesium):
Calcium gluconate is used in the treatment of hypermagnesemia (high levels of magnesium in the blood). Case studies suggest intravenous calcium can aid in the improvement of symptoms. Treatment of magnesium toxicity should only be done under supervision of a qualified healthcare professional.
Grade: A
Black widow spider bite:
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.
Grade: B
High blood potassium level:
Calcium gluconate 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.
Grade: B
High blood pressure:
Several studies have found that introducing calcium to the system can 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 per day of calcium enriched low-fat dairy products reduced systolic and diastolic blood pressure. This research indicates that a calcium intake at the recommended 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.
Grade: B
Premenstrual syndrome (PMS):
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.
Grade: B
Bone stress injury prevention:
Calcium supplementation above normal daily dietary intake did not reduce stress fractures in men. Thus calcium supplementation may not be effective in preventing stress fractures but further studies must be done to validate these results.
Grade: C
Colorectal cancer:
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.
Grade: C
Growth (mineral metabolism in very low birth weight infants):
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.
Grade: C
High blood pressure (pregnancy-induced):
For the general population, meeting current recommendations 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. Treatment of PIH should only be done under supervision of a qualified healthcare professional.
Grade: C
Hyperparathyroidism (secondary):
In patients on hemodialysis, calcium supplementation may reduce secondary hyperparathyroidism (high blood level s 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.
Grade: C
Lead toxicity (acute symptom management):
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.
Grade: C
Osteomalacia / rickets:
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 gluconate is used as an adjuvant in the treatment of rickets and osteomalacia, as well as a single therapeutic agent in non-vitamin 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.
Grade: C
Osteoporosis prevention (steroid-induced):
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 drugpamidronate 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.
Grade: C
Prostate cancer (increased risk):
The lack of agreement among these studies suggests complex interactions among risk factors for prostate cancer. Until the relationship between calcium and prostate cancer is clarified, it is reasonable for men to consume recommended intakes as per the Food and Nutrition Board of the Institute of Medicine. Treatment of prostate cancer should only be done under the supervision of a qualified healthcare professional.
Grade: C
Weight loss:
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.
Grade: C
Vaginal disorders (atrophy, wasting or thinning or the vaginal tissue):
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.
Grade: D
Tradition
WARNING:
DISCLAIMER:
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. Bone density improvement (lactating women), bone loss, carcinoma, cardiac arrest, diarrhea, high cholesterol, intestinal disorders, ischemic stroke (prevention), leg cramps (pregnancy), medullary thyroid cancer (diagnosis), multiple sclerosis, neuromuscular blockade (antagonize), psoriasis, reducing fluoride levels (children), Zollinger-Ellison (diagnosis).
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 percent of the U.S. Recommended Dietary Allowance (RDA) for calcium in a selected serving size. The RDA for calcium is 1,000 milligrams per day for adults (except pregnant or lactating women) and children over four years of age and is used as the standard in nutrition labeling of foods. This allowance is based on the 1968 RDA for 24 sex-age categories set by the Food and Nutrition Board of the National Academy of Sciences. 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 50.
Adults (over 18 years old)
Doses ranging from 400-3,000 milligrams daily of a calcium supplement have been taken by mouth in several studies. Note that there are many forms available. Different conditions may require unique dosing and should be discussed with a qualified healthcare provider. Intravenous (through the vein) calcium may be given by a qualified healthcare provider.
Children (under 18 years old)
Healthy adolescents have received a calcium supplement containing 1,000 milligrams supplemental calcium daily as calcium citrate malate for 14 days, or 1,000 milligrams effervescent calcium tablet daily. A dose of 850 milligrams daily calcium has also been given orally to prepubescent boys in food products. Special dosing may be recommended by a qualified healthcare provider for certain indications.
Safety
DISCLAIMER:
Many complementary techniques are practiced by healthcare professionals with formal training, in accordance with the standards of national organizations. However, this is not universally the case, and adverse effects are possible. Due to limited research, in some cases only limited safety information is available.
Allergies
Avoid in individuals with a known allergy/hypersensitivity to calcium supplements or any of their ingredients. Some people are lactose intolerant. Dairy products contain lactose and dairy products are a common food source of calcium. Lactose intolerance can 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 hypercalcaemia (high levels of calcium in the blood). Conditions causing hypercalcaemia 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 recommended by a qualified healthcare professional. It is also likely safe when used orally and appropriately in pregnancy and lactation, as recommended by a qualified healthcare professional. Routine dietary intake and supplementation in recommended doses are not associated with significant adverse effects.
Avoid calcium supplements made from dolomite, oyster shells, or bone meal because such compounds may contain unacceptable levels of lead. Avoid in patients with hypercalcaemia (high blood levels of calcium), hypercalciuria (high levels of calcium in urine), hyperparathyroidism (high levels of parathyroid hormone), bone tumors, digitalis toxicity, ventricular fibrillation (ventricles of the heart contract in unsynchronized rhythm), kidney stones (renal calculi), kidney disease or disorders, and sarcoidosis (inflammation of lymph nodes and various other tissues).
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 can 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 can be without symptoms or it can cause loss of appetite, nausea, vomiting, constipation, abdominal pain, dry mouth, thirst, frequent urination, and calcium deposition in the heart and kidneys. More severe hypercalcaemia may result in confusion, delirium, coma, and if not treated, death. Hypercalcaemia 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).
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.
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.
Avoid cigarette smoking, as this decreases intestinal calcium absorption and may lead to decreased bone mineral density.
Use cautiously if taking large amounts of vitamin D. Excess calcium in the blood (hypercalcaemia) can cause nausea, vomiting and calcium deposition in the heart and kidneys. This usually results from excessive doses of vitamin D and can be fatal in infants. Consult a qualified healthcare provider.
Use cautiously in individuals with heart arrhythmias and ventricular fibrillation (irregular heart beating). Large fluctuations in free calcium during intravenous calcium infusion can 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.
Pregnancy and Breastfeeding
The Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food, and Nutrition Board suggests that current calcium recommendations for non-pregnant 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 recommends that women who are pregnant or breastfeeding consume calcium each day. For pregnant teens, the recommended 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.
Anticonvulsants decrease calcium absorption by increasing the metabolism of vitamin D. Anticonvulsant intake can lead to hypocalcaemia (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.
Cholestyramine (commonly used for high cholesterol) can reduce the absorption of vitamin D, which, in turn, reduces the absorption of calcium.
Corticosteroids (commonly used for inflammation) can cause significant bone loss (osteoporosis) if the recommended 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 can affect calcium status by reducing the intestinal absorption of calcium. It can 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 can lead to reduced absorption of both if taken at the same time.
Use of 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.
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®) 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.
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 can 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 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.
An interaction between levothyroxine (a thyroid hormone) and calcium carbonate is also possible.
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.
Inulin, found in fresh cheese, does not appear to acutely affect serum ionized calcium concentrations.
Stimulant laxatives (cascara, senna, and bisacodyl) when used for prolonged periods can 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 can cause hypocalcaemia (low levels of blood calcium). Oral magnesium supplements do not affect calcium absorption.
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 can interfere with calcium utilization and retention by reducing the absorption of calcium and vitamin D.
Combined use of non-digestible fructo-oligosaccharides or inulin and calcium may increase the absorption of calcium in the colon.
Calcium taken orally can 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 recommended 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 can 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 can 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 recommended for optimal calcium absorption.
Attribution
This information is based on a systematic review of scientific literature, and was peer-reviewed and edited by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com): Ethan Basch, MD (Memorial Sloan-Kettering Cancer Center); Julie Conquer, PhD (RGB Consulting); Dawn Costa, BA, BS (Natural Standard Research Collaboration); Dana A. Hackman, BS (Northeastern University); Isabell Syelsky, PharmD (Northeastern University); Shaina Tanguay-Colucci, BS (Natural Standard Research Collaboration); Catherine Ulbricht, PharmD (Massachusetts General Hospital); Christine Ulbricht, BS (University of Massachusetts); Wendy Weissner, BA (Natural Standard Research Collaboration); Shannon Welch, PharmD (Northeastern University); Denise Wong, PharmD (Northeastern University).
Bibliography
DISCLAIMER:
Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.
Bolland MJ, Barber PA, Doughty RN, et al. Vascular events in healthy older women receiving calcium supplementation: randomised controlled trial. BMJ 2008 Feb 2;336(7638):262-6.
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.
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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.
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.
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.
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Hyman J, Baron JA, Dain BJ, et al. Dietary and supplemental calcium and the recurrence of colorectal adenomas. Cancer Epidemiol Biomarkers Prev 1998;7(4):291-295.
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.
Luengo M, Pons F, Martinez de Osaba MJ, et al. Prevention of further bone mass loss by nasal calcitonin in patients on long term glucocorticoid therapy for asthma: a two year follow up study. Thorax 1994;49(11):1099-1102.
Mazokopakis EE, Giannakopoulos TG, Starakis IK. Interaction between levothyroxine and calcium carbonate. Can Fam Physician 2008 Jan;54(1):39.
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.
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.
Rudnicki M, Hojsted J, Petersen LJ, et al. Oral calcium effectively reduces parathyroid hormone levels in hemodialysis patients: a randomized double-blind placebo-controlled study. Nephron 1993;65(3):369-374.
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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