Calcium

Calcium/Nutrient Depletion:

  • AntacidsAntacids: According to a review, aluminum- and magnesium-containing antacids increase urinary calcium excretion (71). Use of proton pump inhibitors (esomeprazole) and calcium carbonate or calcium phosphate at the same time may cause decreased absorption of these calcium salts.
  • AnticonvulsantsAnticonvulsants: According to a review, anticonvulsants decrease calcium absorption by increasing the metabolism of vitamin D (71). In vitro and based on a review, anticonvulsant intake led to hypocalcemia and osteomalacia (74; 71).
  • AntidotesAntidotes: According to secondary sources, use of sodium polystyrene sulfonate (SPS) should be avoided with nonabsorbable calcium. Calcium may be depleted with use of SPS, which may cause hypocalcemic tetany.
  • CaffeineCaffeine: According to secondary sources, caffeine may increase urinary calcium excretion, may affect calcium absorption, and has been implicated in osteoporosis; however, research is conflicting.
  • CorticosteroidsCorticosteroids: According to a review, glucocorticoids, such as prednisone, may cause calcium depletion and eventually osteoporosis when they are used for extended periods of time (91)
  • DiureticsDiuretics: In humans, loop diuretics increased calcium excretion (191).
  • FluorideFluoride: According to a review, combined use of fluoride and calcium may decrease the absorption of these minerals (71).
  • GentamicinGentamicin: According to secondary sources, gentamicin may decrease serum calcium.
  • GlucoseGlucose: Interventional trials in nondiabetic participants using dairy products as a source of calcium demonstrated conflicting results, with the majority demonstrating a neutral effect on glucose parameters (223; 224; 225; 226; 227). The effect on blood glucose is not clear.
  • H2 antagonistsH2 antagonists: In humans, use of H2 blockers at the same time as calcium carbonate or calcium phosphate may interfere with the absorption of these calcium salts (98).
  • InositolInositol: In animals, use of inositol hexaphosphate (phytic acid) decreased the absorption of calcium (99).
  • Iron saltsIron salts: In humans, a broad variation in iron absorption was observed in the presence of calcium (100); other studies have demonstrated a lack of an effect on absorption (102). In humans, a statistically significant 30-50% increase in iron absorption was noted when milk or cheese were lacking in meals (101). The researchers suggested that a reasonable separation of calcium and iron supplements or foods may improve iron uptake.
  • LaxativesLaxatives: According to secondary sources, mineral oil and stimulant laxatives decrease calcium absorption.
  • MagnesiumMagnesium: In humans, high calcium intake adversely affected magnesium utilization (105).
  • OrlistatOrlistat: According to human research, 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 (192). Additional human research has reported a lack of effect on calcium levels (193; 194).
  • Parathyroid agentsParathyroid agents: In humans, cinacalcet lowered serum calcium concentrations (104).
  • PhosphorusPhosphorus: According to secondary sources, calcium carbonate or acetate may be used effectively as phosphate binders.
  • PotassiumPotassium: In humans, an inverse association was revealed between potassium and urinary calcium excretion and intestinal calcium absorption (106). A net change in calcium balance was lacking.
  • ThyroxineThyroxine: According to secondary sources, 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 to calcium carbonate in an acidic environment, which may block its absorption. Calcium and levothyroxine should be taken at least four hours apart. Thyroid agents and calcium should be administered four hours apart.
  • ZincZinc: According to secondary sources, combined use of zinc and calcium may decrease the absorption of these minerals. However, these possible mineral interactions have not been shown to be of clinical significance.