Calcium Carbonate & Nutrient Depletion
Also searched as Tums, Os-Cal, Adcal. What the clinical evidence reports, what it may mean, and what to discuss with your pharmacist.
Calcium Carbonate has been associated with depletion of FOLIC ACID, IRON, PHOSPHATE SALTS and CHROMIUM. This does not mean a deficiency will occur — it means these are worth knowing about and, if you take Calcium Carbonate long-term, worth raising with your pharmacist or healthcare provider.
Take more than one medication? Open the checker with Calcium Carbonate pre-loaded and add the rest to see overlapping nutrient signals.
Reported nutrient depletions with Calcium Carbonate
Each record below is shown as published in our licensed clinical database, with its evidence rating and citations. Expand a section for food sources and talking points.
FOLIC ACID
Insignificant DepletionANTACIDS
Folic acid absorption in the small intestine is optimal at a pH of 5.5-6. Chronic use of large doses of antacids can reduce folic acid absorption, but this is likely only significant if dietary folate intake is very low. Advise patients to maintain the recommended daily intake of folic acid in their diet. For information on foods that are rich in folate, see our chart.
Folic acid is a B vitamin your body uses to build healthy cells and support DNA repair. Calcium carbonate is an antacid, and antacids can raise the pH in your stomach and small intestine; since folate absorbs best in a slightly acidic environment, there is a theoretical concern that large, long-term doses could nudge absorption down a little. That said, the evidence rates this as insignificant for most people, so if you eat a reasonable variety of foods, there is generally nothing extra you need to do. If you have questions about your diet or folate intake, your pharmacist or doctor is a great first stop.
What Folic acid (folate) does & food sources
Folate is needed for cell division, red blood cell formation, and healthy fetal development.
Common food sources:
- Leafy green vegetables
- Beans, lentils, and peas
- Fortified grains and cereals
- Citrus fruits
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
What to discuss with your clinician
Ask your provider whether folate monitoring or supplementation is appropriate for you — this matters most before and during pregnancy, and with long-term use of certain seizure or arthritis medications.
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
Supplement considerations
Folate needs are individual. With some medications (for example, methotrexate), folic acid is often prescribed deliberately on a specific schedule — follow your prescriber's instructions rather than adding your own.
Do not start or stop medications or supplements without professional guidance — supplements can interact with prescription medications.
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
Caution: High-dose folic acid can mask vitamin B12 deficiency, so the two are often evaluated together.
Learn more about this nutrient: Folic Acid — uses, safety & interactions
References (2)
- Russell RM, Golner BB, Krasinski SD, et al. Effect of antacid and H2 receptor antagonists on the intestinal absorption of folic acid. J Lab Clin Med 1988;112:458-63.
- Shils ME, Olson JA, Shike M, Ross AC, eds. Modern Nutrition in Health and Disease. 9th ed. Baltimore, MD: Williams & Wilkins, 1999.
IRON
Insignificant DepletionANTACIDS
Gastric acid is important for absorption of dietary, non-heme iron. Antacids may therefore reduce iron absorption by increasing gastric pH and reducing iron solubility. This isn't likely to be clinically significant in most people with adequate dietary iron intake. However, antacids can reduce absorption of iron from supplements by 30% to 40%, and reduced efficacy has occurred occasionally. Advise patients who need iron supplements to avoid antacids or separate the doses as much as possible.
Iron is something your body needs to carry oxygen in your blood and keep your energy up. Calcium carbonate is an antacid, and antacids work by reducing stomach acid. Since stomach acid helps convert dietary iron into a form the body can absorb, taking calcium carbonate regularly can slightly reduce how much iron you take in. For most people eating a normal diet, this is not a meaningful concern, but if you also take an iron supplement, try to space the two apart by a couple of hours and ask your pharmacist whether that timing matters for you.
What Iron does & food sources
Iron is the core of hemoglobin, which carries oxygen in red blood cells.
Common food sources:
- Red meat and poultry
- Beans and lentils
- Fortified cereals
- Spinach (plant iron absorbs better with vitamin C)
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
What to discuss with your clinician
Iron status is easy to assess (ferritin, iron studies, blood counts). Ask your provider before supplementing — unexplained low iron always deserves a medical evaluation for the cause, not just replacement.
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
Supplement considerations
Iron supplements commonly cause constipation or stomach upset and interfere with the absorption of several medications (thyroid medication, some antibiotics). Do not take iron "just in case" — excess iron is harmful.
Do not start or stop medications or supplements without professional guidance — supplements can interact with prescription medications.
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
Caution: Never self-treat suspected anemia; the underlying cause matters as much as the iron level.
Learn more about this nutrient: Iron — uses, safety & interactions
References (3)
- Aymard JP, Aymard B, Netter P, et al. Haematological adverse effects of histamine H2-receptor antagonists. Med Toxicol Adverse Drug Exp 1988;3:430-48. PubMed
- Tatro DS, ed. Drug Interactions Facts. Facts and Comparisons Inc., St. Louis, MO. 1999.
- Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
PHOSPHATE SALTS
Moderate DepletionANTACIDS
Aluminum, calcium, and magnesium contained in antacids can bind phosphate in the gut and prevent its absorption. Antacids are sometimes used therapeutically to decrease high phosphate levels in people with chronic kidney disease. In people with normal kidney function, use of higher-than-recommended doses of antacids for prolonged periods (e.g. over 100 mL daily of Maalox for several months, or 30 mL daily for over 10 years) can cause hypophosphatemia, potentially leading to osteomalacia, fractures, nephrolithiasis, and ureter obstruction.
Phosphate is a mineral your bones, muscles, and cells depend on for energy and structure. Calcium carbonate, when taken regularly, can grab onto phosphate in your digestive tract and carry it out of the body before it gets absorbed, which is actually the same reason doctors sometimes use it intentionally in kidney patients who have too much phosphate. For most people taking a normal dose occasionally, this is not a real concern, but long-term use of higher doses has been linked to genuinely low phosphate levels in some patients. If you use calcium carbonate often or for extended periods, it is worth checking in with your pharmacist or doctor about whether your phosphate levels should be monitored.
Learn more about this nutrient: Phosphate Salts — uses, safety & interactions
References (4)
- Harmelin DL, Martin FR, Wark JD. Antacid-induced phosphate depletion syndrome presenting as nephrolithiasis. Aust NZ J Med 1990;20:803-5. PubMed
- Spencer H, Menaham L. Adverse effects of aluminum-containing antacids on mineral metabolism. Gastroenterology 1979;76:603-6. DOI
- Insogna KL, Bordley DR, Caro JF, Lockwood DH. Osteomalacia and weakness from excessive antacid ingestion. JAMA 1980;244:2544-6. DOI
- Saadeh G, Bauer T, Licata A, Sheeler L. Antacid-induced osteomalacia. Cleve Clin J Med 1987;54:214-6. PubMed
CHROMIUM
Insufficient EvidenceANTACIDS
Antacids increase gastric pH, which might decrease chromium absorption due to formation of less soluble chromium salts. However, the clinical significance of this is not clear.
Chromium is a trace mineral your body uses to help insulin work properly and keep blood sugar steady. Calcium carbonate is an antacid that neutralizes stomach acid, and there is some thinking that a less acidic stomach environment could make chromium harder to absorb. That said, the evidence here is really preliminary, and right now we simply do not know whether this has any meaningful effect in real patients. If you take calcium carbonate regularly and have questions about your nutrition, it is worth mentioning to your pharmacist or doctor.
Learn more about this nutrient: Chromium — uses, safety & interactions
References (3)
- Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002.
- Davis ML, Seaborn CD, and Stoecker BJ. Effects of over-the-counter drugs on chromium retention and urinary excretion in rats. Nutrition Research 1995;15(2):201-210.
- Seaborn CD and Stoecker BJ. Effects of antacid or ascorbic acid on tissue accumulation and urinary excretion of 51chromium. Nutrition Research 1990;10:1401-1407. DOI
This tool is educational and is not a substitute for professional medical advice. An association is not a diagnosis and does not mean a deficiency will occur. Always talk to your pharmacist or healthcare provider before starting, stopping, or changing any medication or supplement.
Disclaimer: This checker finds which nutrients might be depleted by prescription or over-the-counter medications. Each nutrient depletion issue is rated based on clinical significance. Use your own professional judgment prior to making clinical decisions.© 2026 Therapeutic Research Center Licensed records refresh weekly · last updated July 3, 2026.
More about Calcium Carbonate
What drug-induced nutrient depletion means
Some medications can, over time, lower the levels of certain vitamins, minerals, or other nutrients — through reduced absorption, increased loss, or changes in how the body uses them.
Association is not deficiency
An entry here means a depletion has been reported or studied — not that it happens to everyone, or that you are deficient. Dose, duration, diet, and your own health all matter.
Evidence varies by pair
Some drug–nutrient links (like metformin and vitamin B12) are well studied; others rest on limited or preliminary research. Each entry shows the evidence rating from our licensed clinical database.
When to ask about labs
If you take an associated medication long-term, ask your healthcare provider whether monitoring is appropriate for you. Not everyone needs testing — your provider can weigh your dose, duration, and symptoms.
Don't self-supplement blindly
Supplements are not risk-free: some can interact with medications, and some (like potassium or magnesium) can be risky with kidney disease. Talk to your pharmacist before adding anything.
Never stop a medication over this
These medications are prescribed for good reasons, and the benefit usually far outweighs a manageable nutrient consideration. Any change belongs in a conversation with your prescriber.
Food first, usually
For many nutrients, a varied diet covers the gap. Each entry lists common food sources; a supplement is a decision to make with your pharmacist or provider, not a default.
Calcium Carbonate & nutrients: FAQs
Does Calcium Carbonate deplete FOLIC ACID?
Should I take a supplement because I take Calcium Carbonate?
Should I stop taking Calcium Carbonate?
Where does this information come from?
Questions about Calcium Carbonate and your nutrition?
Ask a licensed pharmacist — free, no appointment needed.
Sources & How We Checked
Nutrient depletion records for Calcium Carbonate are evidence-graded and sourced from the Natural Medicines database, and are displayed as published with their citations.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference for drug-induced nutrient depletions, supplements, and interactions — the basis for this page.
- MedlinePlus, U.S. National Library of Medicine — NIH consumer drug information, used for medication overviews across the site.
Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.