Major interaction on record — check this product against your medications before combining. Based on 2 of 3 ingredients. Check your meds →
Dietary supplement

Duo-Cal Ingredients & Drug Interactions

by Douglas Laboratories

Capsule Category: Mineral
Most serious interaction: Major
The interaction bottom line Most serious interaction: Major

Duo-Cal is a dietary supplement by Douglas Laboratories with 3 active ingredients. Its ingredients are commonly taken for detoxification support, hormone balance, estrogen metabolism.Based on those ingredients, 288 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Calcium, Calcium Glucarate. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of Duo-Cal by Douglas Laboratories

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 3 of its 3 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Duo-Cal contains three active ingredients: calcium glucarate, calcium, and calcium phytate. The product provides calcium in two forms — a glucarate and a phytate compound — alongside a separate calcium glucarate ingredient.

Calcium supports bone health, nerve function, and muscle contraction; calcium glucarate is included for its proposed role in supporting the body's natural detoxification pathways, though evidence in humans is limited. The product also contains inactive ingredients: cellulose, vegetable stearate, and silica, which are binders and flow agents in the capsule.

Does it work?

Strong evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Strong

Clinical evidence supports at least one of this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: Bone health and calcium supplementation.
  • We looked for evidence on: Corticosteroid-induced osteoporosis, Exercise-induced muscle damage, Fall prevention, Fetal bone mineralization, Fluorosis, Fractures — and 4 related terms.
  • The strongest evidence on file: Calcium is rated "Effective" for Hypocalcemia (Natural Medicines).
  • Also on file: Calcium is rated "Likely Effective" for Corticosteroid-induced osteoporosis, Osteoporosis.
  • Also on file: Calcium is rated "Possibly Effective" for Fetal bone mineralization, Osteomalacia, Rickets.

The calcium in Duo-Cal is effective for several established uses: treating low blood calcium (hypocalcemia), supporting bone strength in osteoporosis (likely effective), and managing high potassium (hyperkalemia). It's also effective for indigestion (dyspepsia) and kidney failure.

Calcium glucarate, on the other hand, has insufficient evidence to rate its effectiveness for breast, prostate, or colorectal cancer — the data we hold does not establish that it works for these purposes in humans.

The evidence, ingredient by ingredient Calcium D-glucarate Calcium

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 2 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 2 of 2.
  • General safety write-ups exist for 2 of 2.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Calcium in recommended doses is generally well tolerated; most side effects are mild and digestive — belching, constipation, diarrhea, gas, or stomach upset. Rare serious concerns include kidney stones and a condition called calciphylaxis.

Very high doses of calcium may carry a theoretical risk of increased prostate cancer and cardiovascular concerns, though research is mixed and has been criticized for design flaws. Calcium glucarate appears generally well tolerated in small studies, but long-term safety in humans isn't well established.

During pregnancy, calcium at recommended amounts is important and considered likely safe; during breastfeeding, meeting your calcium needs with the recommended amount is safe and encouraged. However, there isn't enough safety information on calcium glucarate to know whether it's safe in pregnancy or while breastfeeding — the data advises against use in both situations.

Side effects, ingredient by ingredient Calcium D-glucarate Calcium

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.

Why this rating?
  • 2 of the 2 matched ingredients can interact with medications — Calcium D-glucarate, Calcium.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: heart-rhythm medications; lithium.
  • For scale: 288 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before you take Duo-Cal, double-check with your doctor or pharmacist if you take dolutegravir or elvitegravir (HIV medications) — calcium can cut their blood levels by a large amount. Also flag intravenous ceftriaxone (an antibiotic), levothyroxine (thyroid hormone), sotalol (heart rhythm drug), raltegravir (HIV medication), diltiazem (blood pressure/heart drug), calcipotriene (psoriasis cream), or any glucuronidated drugs (medications your liver processes through a specific pathway).

If you drink alcohol regularly, mention that too, since it may reduce calcium glucarate activity.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with clinical evidence supporting its stated purpose. Major medication interactions have been identified, and safety information is well characterized.

Duo-Cal's calcium content makes it effective for low blood calcium, bone health, indigestion, and high potassium — but only if you're not taking HIV integrase inhibitors, thyroid hormone, heart rhythm drugs, or several other medications that interact with calcium. The calcium glucarate ingredient lacks human evidence for cancer prevention.

If you take any prescription medications, especially HIV drugs or levothyroxine, check with your doctor or pharmacist before starting this product.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 3 of 3 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jun 25, 2012.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Duo-Cal, straight from the product label.

Brand Douglas Laboratories
Net contents 120 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD Jun 25, 2012
DSLD ID 10233
Product type Mineral
Supplement form Capsule
Dietary claims / uses All Other
Intended target group(s) Adult (18 - 50 Years), Dairy Free, Sugar Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Duo-Cal by Douglas Laboratories, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Vegetarian Capsule(s)
Maximum serving Sizes:
1 Vegetarian Capsule(s)
IngredientAmount% DV
Calcium Glucarate40 mg--
Calcium73 mg--
Calcium Phytate400 mg--

Other ingredients: Cellulose, Vegetable Stearate, Silica

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
FDA Statement of Identity

A Dietary Supplement

Formulation

This product contains NO yeast, wheat gluten, soy protein, milk/dairy, corn, sodium, sugar, starch, art ificial coloring, preservatives or flavoring.

Suggested/Recommended/Usage/Directions

Suggested Usage: As a dietary supplement, adults take 1 capsule daily or as directed by physician.

Precautions

KEEP OUT OF REACH OF CHILDREN.

Tamper resistant package, do not use if outer seal is missing.

Storage

For optimal storage conditions, store in a cool, dry place. (59(0)-77(0)F/15(0)-25(0)C) (35-65% relative humidity)

General

Formula #84071

See for yourself

Duo-Cal by Douglas Laboratories label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

What’s inside

The Ingredients in Duo-Cal by Douglas Laboratories

These are the 3 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Vegetarian Capsule(s) Dosage formCapsule Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Calcium Glucarate

Interacts with
126 drugs
40 mg per serving

Calcium D-glucarate is a supplement form of a natural compound found in fruits and vegetables that is promoted for 'detoxification' and helping the bo...

Calcium Glucarate monograph & interactions

Calcium

Interacts with
168 drugs
73 mg per serving Form: Calcium Glucarate, Calcium Phytate

Calcium is an essential mineral your body needs for strong bones, nerve signaling, and muscle function, and supplements can help fill gaps when diet f...

Calcium monograph & interactions

Calcium Phytate

Interacts with
168 drugs
400 mg per serving

Calcium is an essential mineral your body needs for strong bones, nerve signaling, and muscle function, and supplements can help fill gaps when diet f...

Calcium Phytate monograph & interactions

Other (inactive) ingredients: Cellulose, Vegetable Stearate, Silica. These complete the product’s ingredient list but are not active constituents.

Interaction report

Duo-Cal by Douglas Laboratories Drug Interactions

Want to check YOUR meds against Duo-Cal?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

Go to the checker
288Drugs
7 Major 262 Moderate 19 Minor

Ingredients driving the most interactions

Calcium 168

Each ingredient & the kinds of drugs it affects

For each ingredient in Duo-Cal with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Calcium18 drug types · 168 drugs

Ceftriaxone (Rocephin)

Co-administration of intravenous calcium and ceftriaxone can result in precipitation of a ceftriaxone-calcium salt in the lungs and kidneys.
Avoid administering intravenous calcium in any form, such as parenteral nutrition or Lactated Ringers, within 48 hours of intravenous ceftriaxone. Case reports in neonates show that administering intravenous ceftriaxone and calcium can result in precipitation of a ceftriaxone-calcium salt in the lungs and kidneys. In several cases, neonates have died as a result of this interaction. So far there are no reports in adults; however, there is still concern that this interaction might occur in adults.

Likelihood Probable Evidence D
Dolutegravir (Tivicay)

Calcium seems to reduce levels of dolutegravir.
Advise patients to take dolutegravir either 2 hours before or 6 hours after taking calcium supplements. Pharmacokinetic research suggests that taking calcium carbonate 1200 mg concomitantly with dolutegravir 50 mg reduces plasma levels of dolutegravir by almost 40%. Calcium appears to decrease levels of dolutegravir through chelation.

Likelihood Probable Evidence B
Elvitegravir (Vitekta)

Calcium seems to reduce levels of elvitegravir.
Advise patients to take elvitegravir either 2 hours before or 2 hours after taking calcium supplements. Pharmacokinetic research suggests that taking calcium along with elvitegravir can reduce blood levels of elvitegravir through chelation.

Likelihood Probable Evidence B
Aluminum

Calcium citrate might increase aluminum absorption and toxicity. Other types of calcium do not increase aluminum absorption.
Calcium citrate can increase the absorption of aluminum when taken with aluminum hydroxide. The increase in aluminum levels may become toxic, particularly in individuals with kidney disease. However, the effect of calcium citrate on aluminum absorption is due to the citrate anion rather than calcium cation. Calcium acetate does not appear to increase aluminum absorption.

Likelihood Possible Evidence B
Bictegravir/Emtricitabine/Tenofovir Alafenamide (Biktarvy)

Calcium might decrease levels of bictegravir/emtricitabine/tenofovir alafenamide by reducing its absorption when taken in a fasting state.
Advise patients that bictegravir/emtricitabine/tenofovir alafenamide and calcium can be taken together if taken with food. However, if taken on an empty stomach, bictegravir/emtricitabine/tenofovir alafenamide should not be taken with, or 2 hours after, calcium containing products.

Likelihood Probable Evidence D
Bisphosphonates

Calcium reduces the absorption of bisphosphonates.
Advise patients to take bisphosphonates at least 30 minutes before calcium, but preferably at a different time of day. Calcium supplements decrease absorption of bisphosphonates.

Likelihood Probable Evidence C
Calcipotriene (Dovonex)

Taking calcipotriene with calcium might increase the risk for hypercalcemia.
Calcipotriene is a vitamin D analog used topically for psoriasis. It can be absorbed in sufficient amounts to cause systemic effects, including hypercalcemia. Theoretically, combining calcipotriene with calcium supplements might increase the risk of hypercalcemia.

Likelihood Possible Evidence B
Digoxin (Lanoxin)

Using intravenous calcium with digoxin might increase the risk of fatal cardiac arrhythmias.
Hypercalcemia increases the risk of fatal cardiac arrhythmias with digoxin. However, one retrospective analysis of clinical data suggests that intravenous calcium does not increase the risk of dysrhythmias or mortality in patients receiving digoxin.

Likelihood Possible Evidence B
Diltiazem (Cardizem, Others)

Theoretically, calcium may reduce the therapeutic effects of diltiazem.
Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation. Theoretically, calcium might increase this risk of hypercalcemia and reduce the effectiveness of diltiazem.

Likelihood Probable Evidence D
Levothyroxine (Synthroid, Others)

Calcium seems to reduce the absorption and effectiveness of levothyroxine.
Advise patients to take levothyroxine and calcium supplements at least 4 hours apart. Calcium reduces levothyroxine absorption, probably by forming insoluble complexes. Calcium carbonate supplements reduce effectiveness of levothyroxine in patients with hypothyroidism.

Likelihood Probable Evidence B
Lithium

Theoretically, concomitant use of calcium and lithium may increase this risk of hypercalcemia.
Clinical research suggests that long-term use of lithium may cause hypercalcemia in 10% to 60% of patients. Theoretically, concomitant use of lithium and calcium supplements may further increase this risk.

Likelihood Possible Evidence B
Quinolone Antibiotics

Calcium seems to reduce the absorption of quinolone antibiotics.
Advise patients to take oral quinolones at least 2 hours before or 4-6 hours after calcium supplements or calcium-fortified foods. Taking calcium at the same time as oral quinolones can reduce quinolone absorption. Calcium binds to quinolones in the gut.

Likelihood Probable Evidence B
Raltegravir (Isentress)

Calcium may reduce levels of raltegravir.
Pharmacokinetic research shows that taking a single dose of calcium carbonate 3000 mg along with raltegravir 400 mg twice daily modestly decreases the mean area under the curve of raltegravir, but the decrease does not necessitate a dose adjustment of raltegravir. However, a case of elevated HIV-1 RNA levels and documented resistance to raltegravir has been reported for a patient taking calcium carbonate 1 gram three times daily plus vitamin D3 (cholecalciferol) 400 IU three times daily in combination with raltegravir 400 mg twice daily for 11 months. It is thought that calcium reduced raltegravir levels by chelation, leading to treatment failure.

Likelihood Possible Evidence B
Sotalol (Betapace)

Calcium seems to reduce the absorption of sotalol.
Advise patients to separate doses by at least 2 hours before or 4-6 hours after calcium. Calcium appears to reduce the absorption of sotalol, probably by forming insoluble complexes.

Likelihood Possible Evidence B
Tetracycline Antibiotics

Calcium seems to reduce the absorption of tetracycline antibiotics.
Advise patients to take oral tetracyclines at least 2 hours before, or 4-6 hours after calcium supplements. Taking calcium at the same time as oral tetracyclines can reduce tetracycline absorption. Calcium binds to tetracyclines in the gut.

Likelihood Probable Evidence C
Thiazide Diuretics

Taking calcium along with thiazides might increase the risk of hypercalcemia and renal failure.
Thiazides reduce calcium excretion by the kidneys. Using thiazides along with moderately large amounts of calcium carbonate increases the risk of milk-alkali syndrome (hypercalcemia, metabolic alkalosis, renal failure). Patients may need to have their serum calcium levels and/or parathyroid function monitored regularly.

Likelihood Probable Evidence C
Verapamil (Calan, Others)

Theoretically, calcium may reduce the therapeutic effects of verapamil.
Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation. Theoretically, use of calcium supplements may increase this risk of hypercalcemia and reduce the effectiveness of verapamil.

Likelihood Probable Evidence D
Calcium Channel Blockers

Intravenous calcium may decrease the effects of calcium channel blockers; oral calcium is unlikely to have this effect.
Intravenous calcium is used to decrease the effects of calcium channel blockers in the management of overdose. Intravenous calcium gluconate has been used before intravenous verapamil (Isoptin) to prevent or reduce the hypotensive effects without affecting the antiarrhythmic effects. But there is no evidence that dietary or supplemental calcium when taken orally interacts with calcium channel blockers.

Likelihood Unlikely Evidence D

Calcium Glucarate3 drug types · 126 drugs

Alcohol (Ethanol)

Theoretically, concomitant use with alcohol might decrease calcium D-glucarate activity.
There is some evidence that urinary excretion of calcium D-glucarate metabolites increases in people consuming alcohol.

Likelihood Possible Evidence B
Glucuronidated Drugs

Theoretically, calcium D-glucarate might increase the clearance of drugs that undergo glucuronidation.
The calcium D-glucarate metabolite, D-glucaro-1,4-lactone, inhibits the enzyme beta-glucuronidase, reducing deconjugation of glucuronides in the intestine and thereby reducing reabsorption of the drugs.

Likelihood Possible Evidence B
Kanamycin

Theoretically, calcium D-glucarate may reduce plasma levels of kanamycin.
Calcium D-glucarate may increase the rate of kanamycin elimination, which may decrease its clinical and adverse effects.

Likelihood Possible Evidence D
The maker

Brand information

Manufacturer and brand details for Duo-Cal, from the product label.

Douglas Laboratories

See all Douglas Laboratories products
Name
Douglas Laboratories
Street Address
600 Boyce Road
City
Pittsburgh
State
PA
ZipCode
15205
Pharmacist Counseling Corner

Duo-Cal by Douglas Laboratories: Common Questions

Does Duo-Cal by Douglas Laboratories interact with any medications?
Yes. Based on its ingredients, Duo-Cal has a known interaction with 288 medications, including 7 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Duo-Cal contains 3 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Is Duo-Cal safe to take during pregnancy?
The calcium in Duo-Cal is safe at recommended amounts during pregnancy and is actually important for fetal development. However, there isn't enough safety information on calcium glucarate to know whether it's safe in pregnancy — the available data advises against it. Talk with your doctor or pharmacist about whether this product is right for you.
Can I take Duo-Cal while breastfeeding?
Calcium at recommended amounts is safe and helpful while breastfeeding to meet your calcium needs. Calcium glucarate, though, has insufficient safety data during breastfeeding, and the data advises against use. Check with your doctor or pharmacist to see if this product works for your situation.
What does calcium glucarate actually do?
Calcium glucarate is included for its proposed role in supporting your body's natural detoxification processes. However, we don't have reliable evidence that it works for breast, prostate, or colorectal cancer prevention in humans. More research is needed.
Will Duo-Cal help my bones?
The calcium in Duo-Cal is likely effective for osteoporosis — it supports bone strength when you get enough. It's also effective for low blood calcium. For best results, make sure you're taking a dose your doctor recommends and getting enough vitamin D.
What side effects can calcium cause?
Most common side effects are mild and digestive: belching, constipation, diarrhea, gas, or stomach upset. Rare serious concerns include kidney stones and a condition called calciphylaxis. If you're at risk for either or experience unusual symptoms, let your doctor know.
Can I take Duo-Cal with my levothyroxine?
Not at the same time — calcium significantly reduces how much levothyroxine your body absorbs. You'll need to take levothyroxine and this product at least 4 hours apart. Talk with your pharmacist about the best timing for your dose.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if Duo-Cal is safe with your meds?

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Ask a pharmacist

Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Duo-Cal label
Sources

Sources & How We Checked

Duo-Cal's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 67 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Calcium D-glucarate 5 references
  1. Dwivedi C, Heck WJ, Downie AA, et al. Effect of calcium glucarate on B-glucuronidase activity and glucarate content on certain vegetables and fruits. Biochem Med Metab Bio 1990;43:83-92.
  2. Furuno K, Matsubara S, Ando K, Suzuki S. Preventive effect of D-glucarate against renal damage induced by kanamycin. J Antibiot (Tokyo) 1976;29:950-3. PubMed
  3. Mezey E. Increased urinary excretion of D-glucarate acid in alcoholism. Res Commun Chem Pathol Pharmacol 1976;15:735-42.
  4. Pantuck EJ, Pantuck CB, Anderson KE, et al. Effect of brussels sprouts and cabbage on drug conjugation. Clin Pharmacol Ther 1984;35:161-9. PubMed
  5. Anon. Calcium-D-Glucarate. Altern Med Review 2002;7(4):336-9.

See these in context on the Calcium D-glucarate monograph →

Calcium 62 references
  1. Shils M, Olson A, Shike M. Modern Nutrition in Health and Disease. 8th ed. Philadelphia, PA: Lea and Febiger, 1994.
  2. Hernandez-Avila M, Gonzalez-Cossio T, Hernandez-Avila JE, et al. Dietary calcium supplements to lower blood lead levels in lactating women: a randomized placebo-controlled trial. Epidemiology 2003;14:206-12.. PubMed
  3. Thys-Jacobs S, Ceccarelli S, Bierman A, et al. Calcium supplementation in premenstrual syndrome: a randomized crossover trial. J Gen Intern Med 1989;4:183-9. PubMed
  4. Maton PN, Burton ME. Antacids revisited: a review of their clinical pharmacology and recommended therapeutic use. Drugs 1999;57:855-70.
  5. Clemens JD, Feinstein AR. Calcium carbonate and constipation: a historical review of medical mythopoeia. Gastroenterology 1977;72:957-61. DOI
  6. Saunders D, Sillery J, Chapman R. Effect of calcium carbonate and aluminum hydroxide on human intestinal function. Dig Dis Sci 1988;33:409-13. PubMed
  7. Friedman PA, Bushinsky DA. Diuretic effects on calcium metabolism. Semin Nephrol 1999;19:551-6.
  8. Koo WK, Walters JC, Esterlitz J, et al. Maternal calcium supplementation and fetal bone mineralization. Obstet Gynecol 1999;94:577-82. DOI
  9. Raman L, Rajalakshmi K, Krishnamachari KAVR, et al. Effect of calcium supplementation to undernourished mothers during pregnancy on the bone density of the neonates. Am J Clin Nutr 1978; 31:466-9. DOI
  10. Murry JJ, Healy MD. Drug-mineral interactions: a new responsibility for the hospital dietician. J Am Diet Assoc 1991;91:66-73.
  11. Chan JM, Giovannucci E, Andersson SO, et al. Dairy products, calcium, phosphorous, vitamin D, and risk of prostate cancer. Cancer Causes Control 1998;9:559-66.
  12. Butner LE, Fulco PP, Feldman G, et al. Calcium carbonate-induced hypothyroidism. Ann Intern Med 2000:132:595. PubMed
  13. Schneyer CR. Calcium carbonate and reduction of levothyroxine efficacy. JAMA 1998;279:750. PubMed
  14. Moser LR, Smythe MA, Tisdale JE. The use of calcium salts in the prevention and management of verapamil-induced hypotension. Ann Pharmacother 2000;34:622-9. PubMed
  15. Singh N, Singh PN, Hershman JM. Effect of calcium carbonate on the absorption of levothyroxine. JAMA 2000;283:2822-5. PubMed
  16. Kahela P, Anttila M, Tikkanen R, Sundquist H. Effect of food, food constituents and fluid volume on the bioavailability of sotalol. Acta Pharmacol Toxicol (Copenh) 1979;44:7-12.. PubMed
  17. Pletz MW, Petzold P, Allen A, et al. Effect of calcium carbonate on bioavailability of orally administered gemifloxacin. Antimicrob Agents Chemother 2003;47:2158-60.. PubMed
  18. Bar-Or D, Yoel G. Calcium and calciferol antagonize effect of verapamil in atrial fibrillation. Br Med J 1981;282:1585-6.
  19. Decktor DL, Robinson M, Maton PN, et al. Effects of aluminum/magnesium hydroxide and calcium carbonate on esophageal and gastric pH in subjects with heartburn. Am J Ther 1995;2:546-52. PubMed
  20. Simoneau G. Absence of rebound effect with calcium carbonate. Eur J Drug Metab Pharmacokinet 1996;21:351-7. PubMed
  21. Peters ML, Leonard M, Licata AA. Role of alendronate and risedronate in preventing and treating osteoporosis. Cleve Clin J Med 2001;68:945-51. PubMed
  22. Bourke JF, Mumford R, Whittaker P, et al. The effects of topical calcipotriol on systemic calcium homeostasis in patients with chronic plaque psoriasis. J Am Acad Dermatol 1997;37:929-34.
  23. Gueguen L, Pointillart A. The bioavailability of dietary calcium. J Am Coll Nutr 2000;19:119s-136s. PubMed
  24. Vella A, Gerber TC, Hayes DL, Reeder GS. Digoxin, hypercalcaemia, and cardiac conduction. Postgrad Med J 1999;75:554-6. PubMed
  25. Bania TC, Blaufeux B, Hughes S, et al. Calcium and digoxin vs. calcium alone for severe verapamil toxicity. Acad Emerg Med 2000;7:1089-96. PubMed
  26. Tseng M, Breslow RA, Graubard BI, Ziegler RG. Dairy, calcium, and vitamin D intakes and prostate cancer risk in the National Health and Nutrition Examination Epidemiologic Follow-up Study cohort. Am J Clin Nutr 2005;81:1147-54. PubMed
  27. Weingarten MA, Zalmanovici A, Yaphe J. Dietary calcium supplementation for preventing colorectal cancer and adenomatous polyps. Cochrane Database Syst Rev 2004;(1):CD003548. PubMed
  28. Tavani A, Bertuccio P, Bosetti C, et al. Dietary intake of calcium, vitamin D, phosphorus and the risk of prostate cancer. Eur Urol 2005;48:27-33. PubMed
  29. Giovannucci E, Liu Y, Stampfer MJ, Willett WC. A prospective study of calcium intake and incident and fatal prostate cancer. Cancer Epidemiol Biomarkers Prev 2006;15:203-10. PubMed
  30. Rocephin (ceftriaxone) and calcium interaction. Pharmacist's Letter / Prescriber's Letter 2007;23(10):231005.
  31. Bolland MJ, Barber PA, Doughty RN, et al. Vascular events in healthy older women receiving calcium supplementation: randomised control trial. BMJ 2008;336:262-6.
  32. 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. PubMed
  33. Calcium supplementation and vascular events. Pharmacist's Letter / Prescriber's Letter 2008;24(3):240306.
  34. Dietary reference intakes for calcium and vitamin D. Institute of Medicine, November 30, 2010. Available at: http://www.iom.edu/~/media/Files/Report%20Files/2010/Dietary-Reference-Intakes-for-Calcium-and-Vitamin-D/Vitamin%20D%20and%20Calcium%202010%20Repo
  35. Coburn JW, Mischel MG, Goodman WG, et al. Calcium citrate markedly enhances aluminum absorption from aluminum hydroxide. Am J Kidney Dis. 1991;17(6):708-11. PubMed
  36. Bradley JS, Wassel RT, Lee L, et al. Intravenous ceftriaxone and calcium in the neonate: assessing the risk for cardiopulmonary adverse events. Pediatrics. 2009;123(4):e609-13. PubMed
  37. Kays MB, Overholser BR, Mueller BA, et al. Effects of sevelamer hydrochloride and calcium acetate on the oral bioavailability of ciprofloxacin. Am J Kidney Dis. 2003;42(6):1253-9. PubMed
  38. Neuhofel, A. L., Wilton, J. H., Victory, J. M., Hejmanowsk, L. G., and Amsden, G. W. Lack of bioequivalence of ciprofloxacin when administered with calcium-fortified orange juice: a new twist on an old interaction. J Clin Pharmacol. 2002;42(4):461-466. DOI
  39. Dickinson, H. O., Nicolson, D. J., Cook, J. V., Campbell, F., Beyer, F. R., Ford, G. A., and Mason, J. Calcium supplementation for the management of primary hypertension in adults. Cochrane.Database.Syst.Rev. 2006;(2):CD004639. PubMed
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Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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