Calcium

NOTICE: This health information was not created by the University of Michigan Health System (UMHS) and may not necessarily reflect specific UMHS practices. For medical advice relating to your personal condition, please consult your doctor. Complete disclaimer

Calcium

Uses

Calcium

Calcium is the most abundant, essential mineral in the human body. Of the two to three pounds of calcium contained in the average body, 99% is located in the bones and teeth. Calcium is needed to form bones and teeth and is also required for blood clotting, transmission of signals in nerve cells, and muscle contraction. The importance of calcium for preventing osteoporosis is probably its most well-known role.

What Are "Star" Ratings?

a7_3star   Reliable and relatively consistent scientific data showing a substantial health benefit.

a7_2star   Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.

a7_1star   For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.

Our proprietary “Star-Rating” system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.

For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.

This supplement has been used in connection with the following health conditions:


Used for Amount Why
Gestational Hypertension
 1,200 to 1,500 mg daily 3 stars   Supplementing with calcium may reduce the risk of gestational hypertension.

3 stars  Gestational Hypertension

1,200 to 1,500 mg daily

Calcium deficiency has been implicated as a possible cause of GH.1 , 2 In two preliminary studies, women who developed GH were found to have significantly lower dietary calcium intake than did pregnant women with normal blood pressure.3 , 4 Calcium supplementation has significantly reduced the incidence of GH in preliminary studies5 and in many,6 , 7 , 8 , 9 , 10 , 11 though not all,12 double-blind trials. Calcium supplements may be most effective in preventing GH in women who have low dietary intake of calcium. The National Institutes of Health (NIH) recommends an intake of 1,200 to 1,500 mg of calcium daily during normal pregnancy.13 In women at risk of GH, studies showing reduced incidence have typically used 2,000 mg of supplemental calcium per day,14 , 15 , 16 , 17 , 18 , 19 without any reported maternal or fetal side effects.20 , 21 Nonetheless, many doctors continue to suggest amounts no higher than 1,500 mg per day.

Used for Amount Why
Lactose Intolerance and Calcium Deficiency
 500 to 1,200 mg daily depending on age and other calcium sources 3 stars   As lactose-containing foods are among the best dietary sources of calcium, lactose-intolerant people may want to use calcium supplements as an alternative source.

3 stars  Lactose Intolerance and Calcium Deficiency

500 to 1,200 mg daily depending on age and other calcium sources

Caution: Calcium supplements should be avoided by prostate cancer patients.

Researchers have yet to clearly determine whether lactose-intolerant people absorb less calcium. As lactose-containing foods are among the best dietary sources of calcium, alternative sources of calcium (from food or supplements) are important for lactose-intolerant people. A typical amount of supplemental calcium is 1,000 mg per day.


Used for Amount Why
Osteoporosis
 800 to 1,500 mg daily depending on age and dietary calcium intake 3 stars   Calcium supplements help prevent osteoporosis, especially for girls and premenopausal women. It is often recommended to help people already diagnosed with osteoporosis.

3 stars  Osteoporosis

800 to 1,500 mg daily depending on age and dietary calcium intake

Caution: Calcium supplements should be avoided by prostate cancer patients.

Although insufficient when used as the only intervention, calcium supplements help prevent osteoporosis.22 Though some of the research remains controversial, the protective effect of calcium on bone mass is one of very few health claims permitted on supplement labels by the U.S. Food and Drug Administration.

In some studies, higher calcium intake has not correlated with a reduced risk of osteoporosis—for example, in women shortly after becoming menopausal23 or in men.24 However, after about three years of menopause, calcium supplementation does appear to take on a protective effect for women.25 Even the most positive trials using isolated calcium supplementation show only minor effects on bone mass. Nonetheless, a review of the research shows that calcium supplementation plus hormone replacement therapy is much more effective than hormone replacement therapy without calcium.26 Double-blind research has found that increasing calcium intake results in greater bone mass in girls.27 An analysis of many trials investigating the effects of calcium supplementation in premenopausal women has also shown a significant positive effect.28 Most doctors recommend calcium supplementation as a way to partially reduce the risk of osteoporosis and to help people already diagnosed with the condition. In order to achieve the 1,500 mg per day calcium intake many researchers deem optimal, 800 to 1,000 mg of supplemental calcium are generally added to the 500 to 700 mg readily obtainable from the diet.

While phosphorus is essential for bone formation, most people do not require phosphorus supplementation, because the typical western diet provides ample or even excessive amounts of phosphorus. One study, however, has shown that taking calcium can interfere with the absorption of phosphorus, potentially leading to phosphorus deficiency in elderly people, whose diets may contain less phosphorus.29. The authors of this study recommend that, for elderly people, at least some of the supplemental calcium be taken in the form of tricalcium phosphate or some other phosphorus-containing preparation.

One trial studying postmenopausal women combined hormone replacement therapy with magnesium (600 mg per day), calcium (500 mg per day), vitamin C, B vitamins, vitamin D, zinc, copper, manganese, boron, and other nutrients for an eight- to nine-month period.30 In addition, participants were told to avoid processed foods, limit protein intake, emphasize vegetable over animal protein, and limit consumption of salt, sugar, alcohol, coffee, tea, chocolate, and tobacco. Bone density increased a remarkable 11%, compared to only 0.7% in women receiving hormone replacement alone.


Used for Amount Why
Preeclampsia and High-Risk Women
 1,200 to 1,500 mg daily 3 stars   An analysis of double-blind trials found calcium supplementation to be highly effective in preventing preeclampsia.

3 stars  Preeclampsia and High-Risk Women

1,200 to 1,500 mg daily

Calcium deficiency has been associated with preeclampsia.31 In numerous controlled trials, oral calcium supplementation has been studied as a possible preventive measure.32 33 34 35 While most trials have found a significant reduction in the incidence of preeclampsia with calcium supplementation,36 37 38 39 40 41 One study reported that calcium supplementation reduced both the severity of preeclampsia and the mortality rate in the infants.42

An analysis of double-blind trials46 found calcium supplementation to be highly effective in preventing preeclampsia. However, a large and well-designed double-blind trial and a critical analysis of six double-blind trials concluded that calcium supplementation did not reduce the risk of preeclampsia in healthy women at low risk for preeclampsia.43 For healthy, high-risk (in other words, calcium deficient) women, however, the data show a clear and statistically significant beneficial effect of calcium supplementation in reducing the risk of preeclampsia.44 45 46 47 48 49 50 51 52 53 54 55 56 57

The National Institutes of Health recommends an intake of 1,200 to 1,500 mg of elemental calcium daily during normal pregnancy.58 In women at risk of preeclampsia, most trials showing reduced incidence have used 2,000 mg of supplemental calcium per day.59 Nonetheless, many doctors continue to suggest amounts no higher than 1,500 mg per day.


Used for Amount Why
Premenstrual Syndrome
 1,000 to 1,200 mg daily 3 stars   Calcium appears to reduce the risk of mood swings, bloating, headaches, and other PMS symptoms.

3 stars  Premenstrual Syndrome

1,000 to 1,200 mg daily

Women who consume more calcium from their diets are less likely to suffer severe PMS.60 A large double-blind trial found that women who took 1,200 mg per day of calcium for three menstrual cycles had a 48% reduction in PMS symptoms, compared to a 30% reduction in the placebo group.61 Other double-blind trials have shown that supplementing 1,000 mg of calcium per day relieves premenstrual symptoms.62 , 63

Used for Amount Why
Rickets
 Consult a qualified healthcare practitioner 3 stars   Calcium supplements may be helpful in preventing and treating rickets.

3 stars  Rickets

Consult a qualified healthcare practitioner

Vitamin D and calcium supplements should be used to treat rickets only if a medical professional has diagnosed rickets and has also determined the cause is a nutritional deficiency. Amounts needed to treat rickets should be determined by a doctor and will depend on the age, weight, and condition of the child. For prevention of rickets, 400 IU of vitamin D per day is considered reasonable. Doctors often suggest 1,600 IU per day for treating rickets caused by a lack of dietary vitamin D.

The National Institutes of Health has stated that the following amounts of total calcium intake per day are useful to prevent rickets:

• 400 mg until six months of age

• 600 mg from six to twelve months

• 800 mg from one year through age five

• 800–1,200 mg from age six until age ten

Used for Amount Why
Breast-Feeding Support
 1,000 mg daily 2 stars   Continuing to take prenatal vitamins will help ensure your body gets the nutrients it needs for breast-feeding. Especially important is continued calcium intake.

2 stars  Breast-Feeding Support

1,000 mg daily

A woman should continue to take prenatal vitamins in order to meet the nutrient requirements of breast-feeding. Especially important is continued intake of calcium and calcium-rich foods.

Used for Amount Why
Celiac Disease and Calcium Deficiency
 Consult a qualified healthcare practitioner 2 stars   The malabsorption that occurs in celiac disease can lead to multiple nutritional deficiencies. Supplementing with calcium may correct a deficiency.

2 stars  Celiac Disease and Calcium Deficiency

Consult a qualified healthcare practitioner

Caution: Calcium supplements should be avoided by prostate cancer patients.

The malabsorption that occurs in celiac disease can lead to multiple nutritional deficiencies. The most common nutritional problems in people with celiac disease include deficiencies of essential fatty acids, iron, vitamin D, vitamin K, calcium, magnesium, and folic acid.64 Zinc malabsorption also occurs frequently in celiac disease65 and may result in zinc deficiency, even in people who are otherwise in remission.66 People with newly diagnosed celiac disease should be assessed for nutritional deficiencies by a doctor. Celiac patients who have not yet completely recovered should supplement with a high-potency multivitamin-mineral. Some patients may require even higher amounts of some of these vitamins and minerals—an issue that should be discussed with their healthcare practitioner. Evidence of a nutrient deficiency in a celiac patient is a clear indication for supplementation with that nutrient.

After commencement of a gluten-free diet, overall nutritional status gradually improves. However, deficiencies of some nutrients may persist, even in people who are strictly avoiding gluten. For example, magnesium deficiency was found in 8 of 23 adults with celiac disease who had been following a gluten-free diet and were symptom-free. When these adults were supplemented with magnesium for two years, their bone mineral density increased significantly.67

Used for Amount Why
High Cholesterol
 800 to 1,000 mg daily 2 stars   Some trials have shown that supplementing with calcium reduces cholesterol levels.

2 stars  High Cholesterol

800 to 1,000 mg daily

Caution: Calcium supplements should be avoided by prostate cancer patients.

Some preliminary68 and double-blind69 , 70 trials have shown that supplemental calcium reduces cholesterol levels. Possibly the calcium is binding with and preventing the absorption of dietary fat.71 However, other research has found no substantial or statistically significant effects of calcium supplementation on total cholesterol or HDL (“good”) cholesterol.72 Reasonable supplemental levels are 800 to 1,000 mg per day.


Used for Amount Why
High Triglycerides
 800 mg daily 2 stars   Calcium supplementation has been shown to reduce triglyceride levels.

2 stars  High Triglycerides

800 mg daily

Caution: Calcium supplements should be avoided by prostate cancer patients.

In a preliminary trial, supplementation with 800 mg of calcium per day for one year resulted in a statistically significant 35% reduction in the average TG level among people with elevated cholesterol and triglycerides.73 However, in another trial, calcium supplementation had no effect on TG levels.74 One of the differences between these two trials was that more people in the former trial had initially elevated TG levels.


Used for Amount Why
Hypertension
 800 to 1,500 mg daily 2 stars   Calcium supplementation has been shown to lower blood pressure in people with hypertension.

2 stars  Hypertension

800 to 1,500 mg daily

Caution: Calcium supplements should be avoided by prostate cancer patients.

Calcium supplementation—typically 800–1,500 mg per day—may lower blood pressure. However, while an analysis of 42 trials reported that calcium supplementation led to an average drop in blood pressure that was statistically significant, the actual decrease was small (in medical terms, a drop of 1.4 systolic over 0.8 diastolic pressure).75 Results might have been improved had the analysis been limited to studies of people with hypertension, since calcium has almost no effect on the blood pressure of healthy people. In the analysis of 42 trials, effects were seen both with dietary calcium and with use of calcium supplements. A 12-week trial of 1,000 mg per day of calcium accompanied by blood pressure monitoring is a reasonable way to assess efficacy in a given person.


Used for Amount Why
Obesity
 800 mg daily 2 stars   In a study of obese people following a low-calorie diet, those receiving a calcium supplement lost significantly more weight than those given a placebo.

2 stars  Obesity

800 mg daily

Caution: Calcium supplements should be avoided by prostate cancer patients.

In a study of obese people consuming a low-calorie diet for 24 weeks, those receiving a calcium supplement (800 mg per day) lost significantly more weight than those given a placebo.76 Calcium was effective when provided either as a supplement, or in the form of dairy products. In a second study, however, the amount of weight loss resulting from calcium supplementation (1,000 mg per day) was small and not statistically significant.77 In that study, participants' typical diet contained more calcium than in the study in which calcium supplementation was more effective. Thus, it is possible that calcium supplementation enhances weight loss only when the diet is low in calcium.


Used for Amount Why
Pregnancy and Postpartum Support
 Obtain a total of 1,500 to 2,000 mg daily, including both supplement and food sources 2 stars   Calcium needs double during pregnancy. Supplementing with calcium may reduce the risk of preeclampsia and pre-term delivery and improve the bone strength of the fetuses.

2 stars  Pregnancy and Postpartum Support

Obtain a total of 1,500 to 2,000 mg daily, including both supplement and food sources

Calcium needs double during pregnancy.78 Low dietary intake of this mineral is associated with increased risk of preeclampsia, a potentially dangerous (but preventable) condition characterized by high blood pressure and swelling. Supplementation with calcium may reduce the risk of pre-term delivery, which is often associated with preeclampsia. Calcium may reduce the risk of pregnancy-induced hypertension,79 though these effects are more likely to occur in women who are calcium deficient.80 , 81 Supplementation with up to 2 grams of calcium per day by pregnant women with low dietary calcium intake has been shown to improve the bone strength of the fetuses.82

Pregnant women should consume 1,500 mg of calcium per day from all sources—food plus supplements. Food sources of calcium include dairy products, dark green leafy vegetables, tofu, sardines (canned with edible bones), salmon (canned with edible bones), peas, and beans.

Used for Amount Why
Amenorrhea and Osteoporosis
(Vitamin D)
 Refer to label instructions 1 star   Despite the lack of evidence that calcium and vitamin D supplements alone are helpful to amenorrheic women, they are still generally recommended to prevent the added burden of calcium and vitamin D deficiency from further contributing to bone loss.

1 star  Amenorrhea and Osteoporosis

A preliminary trial showed that bone loss occurred over a one-year period in amenorrheic exercising women despite daily supplementation with 1,200 mg of calcium and 400 IU of vitamin D.83 In a controlled study of amenorrheic nursing women, who ordinarily experience brief bone loss that reverses when menstruation returns, bone loss was not prevented by a multivitamin supplement providing 400 IU of vitamin D along with 500 mg twice daily of calcium or placebo.84 Despite the lack of evidence that calcium and vitamin D supplements alone are helpful to amenorrheic women, they are still generally recommended to prevent the added burden of calcium and vitamin D deficiency from further contributing to bone loss.85 Amounts typically recommended are 1,200 to 1,500 mg calcium and 400 to 800 IU vitamin D daily.

Used for Amount Why
Colon Cancer
 Refer to label instructions 1 star   Through a variety of mechanisms, calcium appears to reduce precancerous conditions in the colon and the risk of colon cancer.

1 star  Colon Cancer

Caution: Calcium supplements should be avoided by prostate cancer patients.

Through a variety of mechanisms, calcium may have anticancer actions within the colon. Most,86 , 87 , 88 but not all,89 preliminary studies have found associations between taking calcium supplements and a reduced risk of colon cancer or precancerous conditions in the colon. In double-blind trials, calcium supplementation has significantly protected against precancerous changes in the colon in some,90 , 91 but not all, reports.92 , 93 While most evidence examining the ability of calcium supplementation to help prevent colon cancer appears hopeful, no research findings yet support the use of calcium supplements in people already diagnosed with colon cancer.


Used for Amount Why
Depression
 Refer to label instructions 1 star   Taken with vitamin D, calcium significantly improved mood in people without depression in one study.

1 star  Depression

Caution: Calcium supplements should be avoided by prostate cancer patients.   

In one double-blind trial, people without depression took 600 IU of vitamin D along with 1,000 mg of calcium, or a placebo, twice daily for four weeks.94 Compared to the placebo, combined vitamin D and calcium supplementation produced significant elevations in mood that persisted at least one week after supplementation was discontinued.


Used for Amount Why
Dysmenorrhea
 Refer to label instructions 1 star   Muscles that are calcium-deficient tend to be hyperactive and therefore might be more likely to cramp. Calcium may help prevent menstrual cramps by maintaining normal muscle tone.

1 star  Dysmenorrhea

In theory, calcium may help prevent menstrual cramps by maintaining normal muscle tone. Muscles that are calcium-deficient tend to be hyperactive and therefore might be more likely to cramp. Calcium supplementation was reported to reduce pain during menses in one double-blind trial,95 though another such study found that it relieved only premenstrual cramping, not pain during menses.96 Some doctors recommend calcium supplementation for dysmenorrhea, suggesting 1,000 mg per day throughout the month and 250–500 mg every four hours for pain relief, during acute cramping (up to a maximum of 2,000 mg per day).

Used for Amount Why
Gingivitis
 Refer to label instructions 1 star   Some doctors recommend calcium to people with gum diseases. Calcium given to people with periodontal disease has been shown to reduce bleeding of the gums and loose teeth.

1 star  Gingivitis

Caution: Calcium supplements should be avoided by prostate cancer patients.

Some,97 but not all,98 research has found that giving 500 mg of calcium twice per day for six months to people with periodontal disease results in a reduction of symptoms (bleeding gums and loose teeth). Although some doctors recommend calcium supplementation to people with diseases of the gums, supportive scientific evidence remains weak.


Used for Amount Why
Insulin Resistance Syndrome
 Refer to label instructions 1 star   One study found that supplementing with calcium improved insulin sensitivity in people with hypertension.

1 star  Insulin Resistance Syndrome

Caution: Calcium supplements should be avoided by prostate cancer patients.

One double blind trial found that 1,500 mg per day of calcium improved insulin sensitivity in people with hypertension.99 No research on the effects of calcium in people with IRS has been done.


Used for Amount Why
Kidney Stones in People Who Are Not Hyperabsorbers of Calcium
 Refer to label instructions 1 star   Calcium appears to interfere with the absorption of oxalate, which reduces the risk of stone formation.

1 star  Kidney Stones in People Who Are Not Hyperabsorbers of Calcium

Caution: Calcium supplements should be avoided by prostate cancer patients.

In the past, doctors have sometimes recommended that people with a history of kidney stones restrict calcium intake because a higher calcium intake increases the amount of calcium in urine. However, calcium (from supplements or food) binds to oxalate in the gut before either can be absorbed, thus interfering with the absorption of oxalate. When oxalate is not absorbed, it cannot be excreted in urine. The resulting decrease in urinary oxalate actually reduces the risk of stone formation,100 and the reduction in urinary oxalate appears to outweigh the increase in urinary calcium.101 In clinical studies, people who consumed more calcium in the diet were reported to have a lower risk of forming kidney stones than people who consume less calcium.102 , 103 , 104

However, while dietary calcium has been linked to reduction in the risk of forming stones, calcium supplements have been associated with an increased risk in a large study of American nurses.105 The researchers who conducted this trial speculate that the difference in effects between dietary and supplemental calcium resulted from differences in timing of calcium consumption. Dietary calcium is eaten with food, and so it can then block absorption of oxalates that may be present at the same meal. In the study of American nurses, however, most supplemental calcium was consumed apart from food.106 Calcium taken without food will increase urinary calcium, thus increasing the risk of forming stones; but calcium taken without food cannot reduce the absorption of oxalate from food consumed at a different time. For this reason, these researchers speculate that calcium supplements were linked to increased risk because they were taken between meals. Thus, calcium supplements may be beneficial for many stone formers, as dietary calcium appears to be, but only if taken with meals.

When doctors recommend calcium supplements to stone formers, they often suggest 800 mg per day in the form of calcium citrate or calcium citrate malate, taken with meals. Citrate helps reduce the risk of forming a stone (see “Dietary changes that may be helpful” above).107 Calcium citrate has been shown to increase urinary citrate in stone formers, which may act as protection against an increase in urinary calcium resulting from absorption of calcium from the supplement.108

Despite the fact that calcium supplementation taken with meals may be helpful for some, people with a history of kidney stone formation should not take calcium supplements without the supervision of a healthcare professional. Although the increase in urinary calcium caused by calcium supplements can be mild or even temporary,109 some stone formers show a potentially dangerous increase in urinary calcium following calcium supplementation; this may, in turn, increase the risk of stone formation.110 People who are “hyperabsorbers” of calcium should not take supplemental calcium until more is known. Using a protocol established years ago in the Journal of Urology, 24-hour urinary calcium studies conducted both with and without calcium supplementation determine which stone formers are calcium “hyperabsorbers.”111 Any healthcare practitioner can order this simple test.


Used for Amount Why
Migraine Headache
 Refer to label instructions 1 star   Taking large amounts of the combination of calcium and vitamin D has been reported to produce a marked reduction in the incidence of migraines in several women.

1 star  Migraine Headache

Caution: Calcium supplements should be avoided by prostate cancer patients.

Taking large amounts of the combination of calcium (1,000 to 2,000 mg per day) and vitamin D has been reported to produce a marked reduction in the incidence of migraines in several women.112 , 113 However, the amount of vitamin D given to these women (usually 50,000 IU once a week), can cause adverse reactions, particularly when used in combination with calcium. This amount of vitamin D should be used only under medical supervision. Doctors often recommend that people take 800 to 1,200 mg of calcium and 400 IU of vitamin D per day. However, it is not known whether theses amounts would have an effect on migraines.


Used for Amount Why
Multiple Sclerosis
 Refer to label instructions 1 star   Calcium levels have been reported to be low in people with MS. In one study, people given a combination of cod liver oil, magnesium, and calcium had a significantly reduced number of MS attacks.

1 star  Multiple Sclerosis

Caution: Calcium supplements should be avoided by prostate cancer patients.

In a small preliminary trial, people with MS were given 20 grams of cod liver oil, as well as approximately 680 mg of magnesium and 1,100 mg of calcium per day in the form of dolomite tablets.114 After one year, the average number of MS attacks decreased significantly for each person. Unlike fish oil capsules, the cod liver oil in this trial contained not only eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), but 5,000 IU of vitamin D. Therefore, it is not known whether the vitamin D or fatty acids were responsible for the cod liver oil’s effects. (One preliminary study found that giving vitamin D-like drugs to animals with MS was helpful.)115 It is also possible that the magnesium and/or calcium given to these people reduced MS attacks. Magnesium116 and calcium117 levels have been reported to be lower in the nerve tissue of people with MS compared with healthy people.

How It Works

How to Use It

The National Academy of Sciences has established guidelines for calcium that are 25–50% higher than previous recommendations. For ages 19 to 50, calcium intake is recommended to be 1,000 mg daily; for adults over age 51, the recommendation is 1,200 mg daily.118 The most common supplemental amount for adults is 800–1,000 mg per day.119 General recommendations for higher daily intakes (1,200–1,500 mg) usually include the calcium most people consume from their diets. Studies indicate the average daily amount of calcium consumed by Americans is about 500–1,000 mg.

Where to Find It

Most dietary calcium comes from dairy products. The myth that calcium from dairy products is not absorbed is not supported by scientific research.120 , 121 Other good sources include sardines, canned salmon, green leafy vegetables, and tofu.

Possible Deficiencies

Severe deficiency of either calcium or vitamin D leads to a condition called rickets in children and osteomalacia in adults. Since vitamin D is required for calcium absorption, people with conditions causing vitamin D deficiency (e.g., pancreatic insufficiency) may develop a deficiency of calcium as well. Vegans (pure vegetarians), people with dark skin, those who live in northern latitudes, and people who stay indoors almost all the time are more likely to be vitamin D deficient than are other people. Vegans often eat less calcium and vitamin D than do other people. Most people eat well below the recommended amount of calcium. This lack of dietary calcium is thought to contribute to the risk of osteoporosis, particularly in white and Asian women.

Interactions

Interactions with Supplements, Foods, & Other Compounds

Some studies have shown that calcium competes for absorption with a number of other minerals, while other studies have found no such competition. To be on the safe side, some doctors recommend that people taking calcium for long periods of time should also take a multimineral supplement.

One study has shown that taking calcium can interfere with the absorption of phosphorus, which, like calcium, is important for bone health.122. Although most western diets contain ample or even excessive amounts of phosphorus, older people who supplement with large amounts of calcium may be at risk of developing phosphorus deficiency. For this reason, the authors of this study recommend that, for elderly people, at least some of the supplemental calcium be taken in the form of tricalcium phosphate or some other phosphorus-containing preparation.

Vitamin D ’s most important role is maintaining blood levels of calcium. Therefore, many doctors recommend that those supplementing with calcium also supplement with 400 IU of vitamin D per day.

Animal studies have shown that essential fatty acids (EFAs) increase calcium absorption from the gut, in part by enhancing the effects of vitamin D and reducing loss of calcium in the urine.123

Lysine supplementation increases the absorption of calcium and may reduce its excretion.124 As a result, some researchers believe that lysine may eventually be shown to have a role in the prevention and treatment of osteoporosis.125

Interactions with Medicines

Certain medicines interact with this supplement.

May Be Beneficial: Some medicines may increase the need for this supplement.
Avoid: Some medicines interact with this supplement, so they should not be taken together.
Check: Some interactions between this supplement and certain medicines require more explanation. Click the link to see details.

Note: The following list only includes the generic or class name of a medicine. To find a specific brand name, use the Medicines Index.

May Be Beneficial: Albuterol
May Be Beneficial: Aluminum Hydroxide
May Be Beneficial: Beclomethasone
May Be Beneficial: Bicalutamide
May Be Beneficial: Budesonide
May Be Beneficial: Busulfan
May Be Beneficial: Caffeine
May Be Beneficial: Calcitonin
May Be Beneficial: Capecitabine
May Be Beneficial: Carboplatin
May Be Beneficial: Carmustine
May Be Beneficial: Chlorambucil
May Be Beneficial: Cholestyramine
May Be Beneficial: Cisplatin
May Be Beneficial: Cladribine
May Be Beneficial: Colesevelam
May Be Beneficial: Colestipol
May Be Beneficial: Cortisone
May Be Beneficial: Cycloserine
May Be Beneficial: Cytarabine
May Be Beneficial: Dexamethasone
May Be Beneficial: Diclofenac
May Be Beneficial: Docetaxel
May Be Beneficial: Etoposide
May Be Beneficial: Felodipine
May Be Beneficial: Floxuridine
May Be Beneficial: Fludarabine
May Be Beneficial: Flunisolide
May Be Beneficial: Fluorouracil
May Be Beneficial: Flurbiprofen
May Be Beneficial: Fluticasone
May Be Beneficial: Gabapentin
May Be Beneficial: Gentamicin
May Be Beneficial: Hydroxychloroquine
May Be Beneficial: Hydroxyurea
May Be Beneficial: Ifosfamide
May Be Beneficial: Indomethacin
May Be Beneficial: Irinotecan
May Be Beneficial: Isoniazid
May Be Beneficial: Levalbuterol
May Be Beneficial: Lomustine
May Be Beneficial: Mechlorethamine
May Be Beneficial: Melphalan
May Be Beneficial: Mercaptopurine
May Be Beneficial: Metformin
May Be Beneficial: Methotrexate
May Be Beneficial: Methylprednisolone
May Be Beneficial: Mineral Oil
May Be Beneficial: Neomycin
May Be Beneficial: Omeprazole
May Be Beneficial: Phenobarbital
May Be Beneficial: Polifeprosan 20 with Carmustine
May Be Beneficial: Prednisolone
May Be Beneficial: Prednisone
May Be Beneficial: Streptozocin
May Be Beneficial: Sucralfate
May Be Beneficial: Sulfamethoxazole
May Be Beneficial: Thioguanine
May Be Beneficial: Thiotepa
May Be Beneficial: Tobramycin
May Be Beneficial: Triamterene
May Be Beneficial: Trimethoprim/ Sulfamethoxazole
May Be Beneficial: Uracil Mustard
May Be Beneficial: Verapamil
May Be Beneficial: Vinblastine
May Be Beneficial: Vincristine
Avoid: Calcium Acetate
Avoid: Ciprofloxacin
Avoid: Demeclocycline
Avoid: Doxycycline
Avoid: Gemifloxacin
Avoid: Nadolol
Avoid: Ofloxacin
Avoid: Sotalol
Avoid: Tetracycline
Avoid: Verapamil
Check: Alendronate
Check: Bendroflumethiazide
Check: Carbamazepine
Check: Chlorothiazide
Check: Chlorthalidone
Check: Desogestrel-Ethinyl Estradiol
Check: Dessicated Thyroid
Check: Erythromycin
Check: Ethinyl Estradiol and Levonorgestrel
Check: Ethinyl Estradiol and Norethindrone
Check: Ethinyl Estradiol and Norgestimate
Check: Ethinyl Estradiol and Norgestrel
Check: Etidronate
Check: Felbamate
Check: Hydrochlorothiazide
Check: Indapamide
Check: Lactase
Check: Levetiracetam
Check: Levonorgestrel
Check: Levonorgestrel-Ethinyl Estrad
Check: Levothyroxine
Check: Liothyronine
Check: Liotrix
Check: Mestranol and Norethindrone
Check: Methyclothiazide
Check: Metolazone
Check: Minocycline
Check: Norgestimate-Ethinyl Estradiol
Check: Oxcarbazepine
Check: Pamidronate
Check: Polythiazide
Check: Primidone
Check: Risedronate
Check: Sodium Fluoride
Check: Topiramate
Check: Trichlormethiazide
Check: Valproate

Side Effects

Side Effects

Constipation , bloating, and gas are sometimes reported with the use of calcium supplements.126 A very high intake of calcium from dairy products combined with large amounts of supplemental calcium carbonate (used as an antacid) was reported in the past to cause a condition called “milk alkali syndrome.” This toxicity is rarely reported today because most medical doctors no longer tell people with ulcers to use this approach as treatment for their condition.

People with hyperparathyroidism, chronic kidney disease, or kidney stones should not supplement with calcium without consulting a physician. For other adults, the highest amount typically suggested by doctors (1,200 mg per day) typically does not cause side effects. People with prostate cancer should avoid supplementing with calcium without medical supervision.

A combined analysis of 15 controlled trials found that long-term calcium supplementation was associated with a significant increase of approximately 30% in the incidence of myocardial infarctions (heart attacks).127 Since these studies were not designed to examine the effect of calcium on heart attack risk, it is possible that the findings in this post hoc (after the fact) analysis were due to chance. A more recent study found that long-term calcium supplementation did not result in an increased incidence of cardiovascular disease-related death or hospitalization.128

In the past, calcium supplements in the forms of bone meal (including microcrystalline hydroxyapatite [MCHC]), dolomite, and oyster shell have sometimes had higher lead levels than permitted by stringent California regulations, though generally less than the levels set by the federal government.129 “Refined” forms (which would include calcium citrate malate [CCM], calcium citrate, and most calcium carbonate) have low levels of lead.130 More recently, a survey of over-the-counter calcium supplements found low or undetectable levels of lead in most products,131 representing a sharp decline in lead content of calcium supplements since 1993. People who decide to take bone meal, dolomite, oyster shell, or coral calcium for long periods of time can contact the supplying supplement company to request independent laboratory analysis showing minimal lead levels.

References

1. Leela R, Yasodhara P, Ramaraju MBBS, Ramaraju LA. Calcium and magnesium in pregnancy. Nutr Res 1991;11:1231–6.

2. Prada JA, Ross R, Clark KE. Hypocalcemia and pregnancy-induced hypertension produced by maternal fasting. Hypertension 1992;20:620–6.

3. Marcous S, Brisson J, Fabia J. Calcium intake from dairy products and supplements and the risk of preeclampsia and gestational hypertension. Am J Epidemiol 1991;133:1226–72.

4. Ortega RM, Martinez RM, Lopez-Sobaler AM, et al. Influence of calcium intake on gestational hypertension. Ann Nutr Metab 1999;43:37–46.

5. Bucher HC, Guyatt GH, Cook RJ, et al. Effect of calcium supplementation on pregnancy-induced hypertension and preeclampsia: a meta-analysis of randomized controlled trials. JAMA 1996;275:1113–7.

6. Bucher HC, Guyatt GH, Cook RJ, et al. Effect of calcium supplementation on pregnancy-induced hypertension and preeclampsia: a meta-analysis of randomized controlled trials. JAMA 1996;275:1113–7.

7. Lopez-Jaramillo P, Narvaez M, Weigle RM, Yepez R. Calcium supplementation reduces the risk of pregnancy-induced hypertension in an Andes population. Br J Obstet Gynaecol 1989;96:648–55.

8. Cong K, Chi S, Lui G. Calcium supplementation during pregnancy for reducing pregnancy induced hypertension. Chin Med J 1995;108:57–9.

9. Purwar M, Kulkarni, H, Motghare V, Dhole S. Calcium supplementation and prevention of pregnancy induced hypertension. J Obstet Gynaecol Res 1996;22:425–30.

10. Belizán JM, Villar J, Gonzalez L, et al. Calcium supplementation to prevent hypertensive disorders of pregnancy. N Engl J Med 1991;325:1399–405.

11. Sanchez-Ramos L, Briones DK, Kaunitz AM, et al. Prevention of pregnancy-induced hypertension by calcium supplementation in angiotensin II-sensitive patients. Obstet Gynecol 1994;84:349–53.

12. Levine RJ, Hauth JC, Curet LB, et al. Trial of calcium to prevent preeclampsia. N Engl J Med 1997;337:69–76.

13. NIH Consensus Development Panel on Optimal Calcium Intake. Optimal calcium intake. Nutrition 1995;11:409–17.

14. Moutquin JM, Garner PR, Burrows RF, et al. Report of the Canadian Hypertension Society Consensus Conference: 2. Nonpharmacologic management and prevention of hypertensive disorders in pregnancy. CMAJ 1997;157:907–19.

15. Cong K, Chi S, Lui G. Calcium supplementation during pregnancy for reducing pregnancy induced hypertension. Chin Men J 1995;108:57–9.

16. Bucher HC, Guyatt GH, Cook RJ, et al. Effect of calcium supplementation on pregnancy-induced hypertension and preeclampsia: a meta-analysis of randomized controlled trials. JAMA 1996;275:1113–7.

17. Lopez-Jaramillo P, Narvaez M, Weigel RM, Yepez R. Calcium supplementation reduces the risk of pregnancy-induced hypertension in an Andes population. Br J Obstet Gynaecol 1989;96:648–55.

18. Purwar M, Julkarni H, Motghare V, Dhole S. Calcium supplementation and prevention of pregnancy induced hypertension. J Obstet Gynaecol Res 1996;22:425–30.

19. Sanchez-Ramos L, Briones DK, Kaunitz AM, et al. Prevention of pregnancy-induced hypertension by calcium supplementation in angiotensin II-sensitive patients. Obstet Gynecol 1994;84:349–53.

20. Moutquin JM, Garner PR, Burrows RF, et al. Report of the Canadian Hypertension Society Consensus Conference: 2. Nonpharmacologic management and prevention of hypertensive disorders in pregnancy. CMAJ 1997;157:907–19.

21. Cong K, Chi S, Lui G. Calcium supplementation during pregnancy for reducing pregnancy induced hypertension. Chin Men J 1995;108:57–9.

22. Reid IR, Ames RW, Evans MC, et al. Long-term effects of calcium supplementation on bone loss and fractures in postmenopausal women: a randomized controlled trial. Am J Med 1995;98:331–5.

23. Hosking DJ, Ross PD, Thompson DE, et al. Evidence that increased calcium intake does not prevent early postmenopausal bone loss. Clin Ther 1998;20:933–44.

24. Owusu W, Willett WC, Feskanich D, et al. Calcium intake and the incidence of forearm and hip fractures among men. J Nutr 1997;127:1782–7.

25. Rulm LA, Sakhaee K, Peterson R, et al. The effect of calcium citrate on bone density in the early and mid-postmenopausal period: a randomized, placebo-controlled study. Am J Ther 1999;6:303–11.

26. Nieves JW, Komar L, Cosman F, Lindsay R. Calcium potentiates the effect of estrogen and calcitonin on bone mass: review and analysis. Am J Clin Nutr 1998;67:18–24.

27. Bonjour JP, Carrie AL, Ferrari S, et al. Calcium-enriched foods and bone mass growth in prepubertal girls: a randomized, double-blind, placebo-controlled trial. J Clin Invest 1997;99:1287–94.

28. Welten DC, Kemper HC, Post GB, et al. A meta-analysis of the effect of calcium intake on bone mass in young and middle aged females and males. J Nutr 1995;125:2802–13.

29. Heaney RP, Nordin BEC. Calcium effects on phosphorus absorption: implications for the prevention and co-therapy of osteoporosis.J Am Coll Nutr 2002;21:239–44.

30. Abraham GE, Grewal H. A total dietary program emphasizing magnesium instead of calcium. J Reprod Med 1990;35:503–7.

31. 33. Hojo M, August P. Calcium metabolism in normal and hypertensive pregnancy. *Semin Nephrol* 1995;15:504–11 [review].

32. Hojo M, August P. Calcium Metabolism in Preeclampsia: Supplementation may help. *Medscape Womens Health* 1997;2:5.

33. Moutquin JM, Garner PR, Burrows RF, et. al. Report of the Canadian Hypertension Society Consensus Conference: 2. Nonpharmacologic management and prevention of hypertensive disorders in pregnancy. *CMAJ* 1997;157:907–19.

34. Levine RJ, Hauth JC, Curet LB, et al. Trial of calcium to prevent preeclampsia. *N Engl J Med* 1997;337:69–76.

35. Belizan JM, Villar J, Gonzalez, et al. Calcium supplementation to prevent hypertensive disorders of pregnancy. *N Engl J Med* 1991;325:1399–405.

36. Hojo M, August P. Calcium Metabolism in Preeclampsia: Supplementation may help. *Medscape Womens Health* 1997;2:5.

37. Moutquin JM, Garner PR, Burrows RF, et al. Report of the Canadian Hypertension Society Consensus Conference: 2. Nonpharmacologic management and prevention of hypertensive disorders in pregnancy. *CMAJ* 1997;157:907–19.

38. Crowther CA, Hiller JE, Pridmore B, et al. Calcium supplementation in nulliparous women for the prevention of pregnancy-induced hypertension, preeclampsia, and preterm birth: an Australian randomized trial. FRACOG and the ACT study group. *Aust N Z J Obstet Gynaecol* 1999;39:12–8.

39. Bucher HC, Guyatt GH, Cook RJ, et al. Effect of calcium supplementation on pregnancy-induced hypertension and preeclampsia: a meta-analysis of randomized controlled trials. *JAMA* 1996;275:1113–7.

40. Belizan JM, Villar J, Gonzalez, et al. Calcium supplementation to prevent hypertensive disorders of pregnancy. *N Engl J Med* 1991;325:1399–405.

41. Herrera JA, Arevalo-Herrera M, Herrera S. Prevention of preeclampsia by linoleic acid and calcium supplementation: a randomized controlled trial. *Obstet Gynecol* 1998;91:585–90.

42. Levine RJ, Hauth JC, Curet LB, et al. Trial of calcium to prevent preeclampsia. *N Engl J Med* 1997;337:69–76.

43. Villar J, Abdel-Aleem H, Merialdi M, et al. World Health Organization randomized trial of calcium supplementation among low calcium intake pregnant women. *Am J Obstet Gynecol* 2006;194:639–49.

44. Villar J, Abdel-Aleem H, Merialdi M, et al. World Health Organization randomized trial of calcium supplementation among low calcium intake pregnant women. *Am J Obstet Gynecol* 2006;194:639–49.

45. Bucher HC, Guyatt GH, Cook RJ, et al. Effect of calcium supplementation on pregnancy-induced hypertension and preeclampsia: a meta-analysis of randomized controlled trials. *JAMA* 1996;275:1113–7.

46. Levine RJ, Hauth JC, Curet LB, et al. Trial of calcium to prevent preeclampsia. *N Engl J Med* 1997;337:69–76.

47. Sibai BM. Prevention of preeclampsia: a big disappointment. *Am J Obstet Gynecol* 1998;179:1275–8.

48. Levine RJ, Hauth JC, Curet LB, et al. Trial of calcium to prevent preeclampsia. *N Engl J Med* 1997;337:69–76.

49. Lopez-Jaramillo P, Narvaez M, Weigel RM, Yepez R. Calcium supplementation reduces the risk of pregnancy-induced hypertension in an Andes population. *Br J Obstet Gynaecol* 1989;96:648–55.

50. Lopez-Jaramillo P, Narvaez M, Felix C, Lopez A. Dietary calcium supplementation and prevention of pregnancy hypertension. *Lancet* 1990;335:293. [letter]

51. Villar J, Repke JT. Calcium supplementation during pregnancy may reduce preterm delivery in high-risk populations. *Am J Obstet Gynecol* 1990;163:1124–31.

52. Belizan JM, Villar J, Gonzalez L. Calcium supplementation to prevent hypertensive disorders of pregnancy. N Engl J Med 1991;325:1399–405.

53. Belizan JM, Villar J, Gonzalez L. Calcium supplementation to prevent hypertensive disorders of pregnancy. *N Engl J Med* 1991;325:1399–405.

54. Sanchez-Ramos L, Briones DK, Kaunitz AM, et al. Prevention of pregnancy-induced hypertension by calcium supplementation in angiotensin II-sensitive patients. *Obstet Gynecol* 1994;84:349–53.

55. DerSimonian R, Levine RJ. Resolving discrepancies between a meta-analysis and a subsequent large controlled trial. *JAMA* 1999;282:664–70 [review].

56. Ritchie LD, King JC. Dietary calcium and pregnancy-induced hypertension: is there a relation? *Am J Clin Nutr* 2000;71(5 Suppl):1371–4S [review].

57. Villar J, Belizan JM. Same nutrient, different hypotheses: disparities in trials of calcium supplementation during pregnancy. *Am J Clin Nutr* 2000;71(5 Suppl):1375–9S [review].

58. NIH Consensus conference. Optimal calcium intake. NIH Consensus Development Panel on Optimal Calcium Intake. *JAMA* 1994;272(24):1942 [review].

59. Moutquin JM, Garner PR, Burrows RF, et al. Report of the Canadian Hypertension Society Consensus Conference: 2. Nonpharmacologic management and prevention of hypertensive disorders in pregnancy. *CMAJ* 1997;157:907–19.

60. Rossignol AM, Bonnlander H. Premenstrual symptoms and beverage consumption. Am J Obstet Gynecol 1993;168:1640 [letter].

61. Thys-Jacobs S, Starkey P, Bernstein D, et al. Calcium carbonate and the premenstrual syndrome: Effects on premenstrual and menstrual symptoms. Am J Obstet Gynecol 1998;179:444–52.

62. Thys-Jacobs S, Ceccarelli S, Bierman A, et al. Calcium supplementation in premenstrual syndrome. J Gen Intern Med 1989;4:183–9.

63. Penland JG, Johnson PE. Dietary calcium and manganese effects on menstrual cycle symptoms. Am J Obstet Gynecol 1993;168:1417–23.

64. Connon JJ. Celiac disease. In: Shils ME, Olson JA, Shike M, eds. Modern Nutrition in Health and Disease, 8th ed. Philadelphia: Lea & Febiger, 1994, 1062.

65. Crofton RW, Glover SC, Ewen SWB, et al. Zinc absorption in celiac disease and dermatitis herpetiformis: a test of small intestinal function. Am J Clin Nutr 1983;38:706–12.

66. Solomons NW, Rosenberg IH, Sandstead HH. Zinc nutrition in celiac sprue. Am J Clin Nutr 1976;29:371–5.

67. Rude RK, Olerich M. Magnesium deficiency: possible role in osteoporosis associated with gluten-sensitive enteropathy. Osteoporos Int 1996;6:453–61.

68. Yacowitz H, Fleischman AI, Bierenbaum ML. Effects of oral calcium upon serum lipids in man. Br Med J 1965;1:1352–4.

69. Bell L, Halstenson CE, Halstenson CJ, et al. Cholesterol-lowering effects of calcium carbonate in patients with mild to moderate hypercholesterolemia. Arch Intern Med 1992;152:2441–4.

70. Karanja N, Morris CD, Illingworth DR, Plasma lipids and hypertension: response to calcium supplementation. Am J Clin Nutr 1987;45:60–5.

71. Denke MA, Fox MM, Schulte MC. Short-term dietary calcium fortification increases fecal saturated fat content and reduces serum lipids in men. J Nutr 1993;123:1047–53.

72. Bostick RM, Fosdick L, Grandits GA, et al. Effect of calcium supplementation on serum cholesterol and blood pressure. Arch Fam Med 2000;9:31–9.

73. Bierenbaum ML, Fleischman AI, Raichelson RI. Long term human studies on the lipid effects of oral calcium. Lipids 1972;7:202–6.

74. Carlson LA, Olsson AG, Oro L, Rossner S. Effects of oral calcium upon serum cholesterol and triglycerides in patients with hyperlipidemia. Atherosclerosis 1971;14:391–400.

75. Griffith LE, Guyatt GH, Cook RJ, et al. The influence of dietary and nondietary calcium supplementation on blood pressure. An updated metaanalysis of randomized controlled trials. Am J Hypertens 1999;12:84–92.

76. Zemel MB, Thompson W, Milstead A, et al. Calcium and dairy acceleration of weight and fat loss during energy restriction in obese adults. Obes Res 2004;12:582–90.

77. Shapses SA, Heshka S, Heymsfield SB. Effect of calcium supplementation on weight and fat loss in women. J Clin Endocrinol Metab 2004;89:632–7.

78. Truswell AS. ABC of nutrition. Nutrition for pregnancy. Br Med J 1985;291:263–6.

79. Villar J, Repke JT. Calcium supplementation during pregnancy may reduce preterm delivery in high-risk populations. Am J Obstet Gynecol 1990;163:1124–31.

80. Ritchie LD, King JC. Dietary calcium and pregnancy-induced hypertension: is there a relation? Am J Clin Nutr 2000;71(5 Suppl):1371S–4S [review].

81. Villar J, Belizan JM. Same nutrient, different hypotheses: disparities in trials of calcium supplementation during pregnancy. Am J Clin Nutr 2000;71(5 Suppl):1375S–9S [review].

82. Koo WWK, Walters JC, Esterlitz J, et al. Maternal calcium supplementation and fetal bone mineralization. Obstet Gynecol 1999;94:577–82.

83. Baer JT, Taper LJ, Gwazdauskas FG, et al. Diet, hormonal, and metabolic factors affecting bone mineral density in adolescent amenorrheic and eumenorrheic female runners. J Sports Med Phys Fitness 1992;32:51–8.

84. Kalkwarf HJ, Specker BL, Ho M. Effects of calcium supplementation on calcium homeostasis and bone turnover in lactating women. J Clin Endocrinol Metab 1999;84:464–70.

85. Fagan KM. Pharmacologic management of athletic amenorrhea. Clin Sports Med 1998;17:327–41 [review].

86. Whelan RL, Horvath KD, Gleason NR, et al. Vitamin and calcium supplement use is associated with decreased adenoma recurrence in patients with a previous history of neoplasia. Dis Colon Rectum 1999;42:212–7.

87. White E, Shannon JS, Patterson RE. Relationship between vitamin and calcium supplement use and colon cancer. Cancer Epidemiol Biomarkers Prev 1997;6:769–74.

88. Kampman E, Slattery ML, Caan B, Potter JD. Calcium, vitamin D, sunshine exposure, dairy products and colon cancer risk (United States). Cancer Causes Control 2000;11:459–466.

89. Neugut AI, Horvath K, Whelan RL, et al. The effect of calcium and vitamin supplements on the incidence and recurrence of colorectal adenomatous polyps. Cancer 1996;78:723–8.

90. Baron JA, Beach M, Mandel JS, et al. Calcium supplements for the prevention of colorectal adenomas. N Engl J Med 1999;340:101–7.

91. Bostick RM, Fosdick L, Wood JR, et al. Calcium and colorectal epithelial cell proliferation in sporadic adenoma patients: a randomized, double-blinded, placebo-controlled clinical trial. J Natl Cancer Inst 1995;87:1307–15.

92. Cats A, Kleibeuker JH, van der Meer R, et al. Randomized, double-blinded, placebo-controlled intervention study with supplemental calcium in families with hereditary nonpolyposis colorectal cancer. J Natl Cancer Inst 1995;87:598–603.

93. Baron JA, Tosteson TD, Wargovich MJ, et al. Calcium supplementation and rectal mucosal proliferation: a randomized controlled trial. J Natl Cancer Inst 1995;87:1303–7.

94. Arasteh K. A beneficial effect of calcium intake on mood. J Orthomolec Med 1994;9:199–204.

95. Penland J, Johnson P. Dietary calcium and manganese effects on menstrual cycle symptoms. Am J Obstet Gynecol 1993;168:1417–23.

96. Thys-Jacobs S, Starkey P, Bernstein D, et al. Calcium carbonate and the premenstrual syndrome: effects on premenstrual and menstrual symptoms. Am J Obstet Gyencol 1998;179:444–52.

97. Krook L, Lutwak L, Whalen JP, et al. Human periodontal disease. Morphology and response calcium therapy. Cornell Vet 1972;62:32–53.

98. Uhrbom E, Jacobson L. Calcium and periodontitis: a clinical effect of calcium medication. J Clin Periodontol 1984;11:230–41.

99. Sanchez M, de la Sierra A, Coca A, Oral calcium supplementation reduces intraplatelet free calcium concentration and insulin resistance in essential hypertensive patients. Hypertension 1997;29:531–6.

100. Marshall RW, Cochran M, Hodgkinson A. Relationship between calcium and oxalic acid intake in the diet and their excretion in the urine of normal and renal-stone forming subjects. Clin Sci 1972;43:91–9.

101. Lemann J Jr. Composition of the diet and calcium kidney stones. N Engl J Med 1993;328:880–2 [editorial].

102. Curhan GC, Willett WC, Rimm EB, Stampfer MJ. A prospective study of dietary calcium and other nutrients and the risk of symptomatic kidney stones. N Engl J Med 1993;328:833–8.

103. Hassapidou MN, Paraskevopoulos S Th, Karakoltsidis PA, et al. Dietary habits of patients with renal stone disease in Greece. J Human Nutr Dietet 1999;12:47–51.

104. Sowers MFR, Hannausch M, Wood C, et al. Prevalence of renal stones in a population-based study with dietary calcium, oxalate, and medication exposures. Am J Epidemiol 1998;147:914–20.

105. Curhan GC, Willett WC, Speizer FE, et al. Comparison of dietary calcium with supplemental calcium and other nutrients as factors affecting the risk for kidney stones in women. Ann Intern Med 1997;126:497–504.

106. Curhan GC, Willett WC, Speizer FE, Stampfer MJ. A prospective study of dietary and supplemental calcium and the risk of kidney stones in women. Am J Epidemiol 1996;143(11Suppl):S15 [abstr #57].

107. Pak CY. Nephrolithiasis from calcium supplementation. J Urol 1987;137:1212–3 [editorial].

108. Levine BS, Rodman JS, Wienerman S, et al. Effect of calcium citrate supplementation on urinary calcium oxalate saturation in female stone formers: implications for prevention of osteoporosis. Am J Clin Nutr 1994;60:592–6.

109. Pak CY, Sakhaee K, Hwang TIS, et al. Nephrolithiasis from calcium supplementation. J Urol 1987;137:1212–3 [editorial/review].

110. Bataille IP, Charransol G, Gregoire I, et al. Effect of calcium restriction on renal excretion of oxalate and the probability of stones in the various pathophsiological groups with calcium stones. J Urol 1983;130:218–23.

111. Bataille P, Charransol G, Gregoire I, et al. Effect of calcium restriction on renal excretion of oxalate and the probability of stones in the various pathophsiological groups with calcium stones. J Urol 1983;130:218–23.

112. Thys-Jacobs S. Vitamin D and calcium in menstrual migraine. Headache 1994;34:544–6.

113. Thys-Jacobs S. Alleviation of migraines with therapeutic vitamin D and calcium. Headache 1994;34:590–2.

114. Goldberg P, Fleming MC, Picard EH. Multiple sclerosis: decreased relapse rate through dietary supplementation with calcium, magnesium and vitamin D. Med Hypothesis 1986;21:193–200.

115. DeLuca HF, Zierold C. Mechanisms and functions of vitamin D. Nutr Rev 1998;56(2 Pt 2):S4–10 [review].

116. Yasui M, Yase Y, Ando K, et al. Magnesium concentration in brains from multiple sclerosis patients. Acta Neurol Scand 1990;81:197–200.

117. Yasui M, Ota K. Experimental and clinical studies on dysregulation of magnesium metabolism and the aetiopathogenesis of multiple sclerosis. Magnes Res 1992;5:295–302.

118. Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and Nutrition Board, Institute of Medicine. Dietary reference intakes for calcium, phosphorus, magnesium, vitamin D and fluoride. Washington DC: National Academy Press, 1997, 108–17 [review].

119. Heaney RP, Recker RR, Weaver CM. Absorbability of calcium sources: the limited role of solubility. Calcif Tissue Int 1990;46:300–4.

120. Sheikh MS, Santa Ana CA, Nicar MJ, et al. Gastrointestinal absorption of calcium from milk and calcium salts. N Engl J Med 1987;317:532–6.

121. Levenson DI, Bockman RS. A review of calcium preparations. Nutr Rev 1994;52:221–32 [review].

122. Heaney RP, Nordin BEC. Calcium effects on phosphorus absorption: implications for the prevention and co-therapy of osteoporosis.J Am Coll Nutr 2002;21:239–44.

123. Kruger MC, Horrobin DF. Calcium metabolism, osteoporosis and essential fatty acids: a review. Prog Lipid Res 1997;36:131–51 [review].

124. Civitelli R, Villareal DT, Agnusdei D, et al. Dietary L-lysine and calcium metabolism in humans. Nutrition 1992;8:400–5.

125. Flodin NW. The metabolic roles; pharmacology, and toxicology of lysine. J Am Coll Nutr 1997;16:7–21 [review].

126. Levenson DI, Bockman RS. A review of calcium preparations. Nutr Rev 1994;52:221–32 [review].

127. Bolland MJ, Avenell A, Baron JA, et al. Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis. BMJ 2010;341:c3691.

128. Lewis JR, Calver J, Zhu K, et al. Calcium supplementation and the risks of atherosclerotic vascular disease in older women: results of a 5-year RCT and a 4.5-year follow-up. J Bone Miner Res 2011;26:35–41.

129. Burros M. Testing calcium supplements for lead. New York Times June 4, 1997, B7.

130. Bourgoin BP, Evans DR, Cornett JR, et al. Lead content in 70 brands of dietary calcium supplements. Am J Public Health 1993;83:1155–60.

131. Ross EA, Szabo NJ, Tebbett IR. Lead content of calcium supplements. JAMA 2000;284:1425–9.

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.

Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.