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While some complementary and alternative techniques have been studied scientifically, high-quality data regarding safety, effectiveness, and mechanism of action are limited or controversial for most therapies. Whenever possible, it is recommended that practitioners be licensed by a recognized professional organization that adheres to clearly published standards. In addition, before starting a new technique or engaging a practitioner, it is recommended that patients speak with their primary healthcare provider(s). Potential benefits, risks (including financial costs), and alternatives should be carefully considered. The below monograph is designed to provide historical background and an overview of clinically-oriented research, and neither advocates for or against the use of a particular therapy.

Related Terms

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


  • The Romans used lime (calcium oxide), clacked lime (calcium hydroxide), and hydraulic cement in construction works. Calcium (Latin calx, meaning "lime") was first isolated in its metallic form by Sir Humphrey Davy in 1808 through the electrolysis of a mixture of calcium oxide and mercury oxide.
  • Chelated calcium refers to the way in which calcium is chemically combined with another substance. Calcium citrate is an example of such a chelated preparation. Calcium may also be combined with other substances to form preparations such as calcium lactate or calcium gluconate. Calcium carbonate may be refined from limestone, natural elements of the earth, or from shell sources, such as oyster. Shell sources are often described on the label as a "natural" source. Calcium carbonate from oyster shells is not "refined" and may contain variable amounts of lead.
  • Calcium is the most abundant mineral in the human body and has several important functions. More than 99% of total body calcium is stored in the bones and teeth where it supports the structure. The remaining 1% is found throughout the body in blood, muscle, and the intracellular fluid. Calcium is needed for muscle contraction, blood vessel constriction and relaxation, the secretion of hormones and enzymes, and nervous system signaling. A constant level of calcium is maintained in body fluid and tissues so that these vital body processes function efficiently.
  • The body gets the calcium it needs in two ways. One method is dietary intake of calcium-rich foods including dairy products, which have the highest concentration per serving of highly absorbable calcium, and dark, leafy greens or dried beans, which have varying amounts of absorbable calcium. Calcium is an essential nutrient required in substantial amounts, but many diets are deficient in calcium.
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The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

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

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Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

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Author Information

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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 Selected references are listed below.

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