Does My Medication Cause Nutrient Depletion?
Some prescription and over-the-counter medications can lower your levels of important vitamins and minerals over time. Search your medication below to see what it may deplete — with evidence ratings and what to discuss with your pharmacist.
Potential nutrient considerations for your selected medication
1 medication checked · 6 nutrients with reported associations. These are talking points for your care team — not a diagnosis.
CALCIUM
Insignificant DepletionH2-BLOCKERS
Calcium must be solubilized in order to be absorbed. The solubility of calcium is dependent on an acidic pH. Therefore, it has been assumed that decreased gastric acidity decreases absorption of calcium supplements. Some evidence also shows that patients with low gastric acid have lower calcium absorption in a fasting state compared to people with normal gastric acid secretion. Calcium citrate is significantly better absorbed than calcium carbonate in these patients in a fasting state. However, when taken with a meal, decreased gastric acidity due to drugs such as H2 blockers or due to achlorhydria, does not seem to significantly impair absorption of calcium carbonate or calcium citrate. For information on foods that are rich in calcium, see our chart.
What Calcium does & food sources
Calcium builds and maintains bone and is essential for muscle contraction and nerve signaling.
Common food sources:
- Dairy products (milk, yogurt, cheese)
- Fortified plant milks and juices
- Canned fish with bones (sardines, salmon)
- Leafy greens like kale
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
What to discuss with your clinician
Ask your provider whether bone health monitoring (and vitamin D testing) makes sense with long-term use of an associated medication — a blood calcium level alone does not capture bone calcium status.
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
Supplement considerations
Calcium can interfere with the absorption of several medications (some antibiotics, thyroid medication, iron) — separate the doses and confirm timing with your pharmacist. Total intake from food plus supplements matters more than supplements alone.
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: Very high calcium intake has its own risks (kidney stones in susceptible people) — more is not better.
FOLIC ACID
Insignificant DepletionH2 BLOCKERS
Folic acid absorption from the small intestine is optimal at a pH of 5.5-6. The increased pH associated with use of H2 blockers may therefore reduce folic acid absorption, but this is probably only significant if dietary folate intake is very low. Advise patients to maintain the recommended daily dietary intake of folic acid. For information on foods that are rich in folate, see our chart.
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.
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.
- Termanini B, Gibril F, Sutliff VE, et al. Effect of long-term gastric acid suppressive therapy on serum vitamin B12 levels in patients with Zollinger-Ellison syndrome. Am J Med 1998;104:422-30. PubMed
IRON
Insignificant DepletionH2-BLOCKERS
Gastric acid is important for the absorption of iron, particularly dietary non-heme iron. Dose-dependent reductions in dietary iron absorption have been noted with cimetidine, ranging from 28% to 65% with single doses of 300-900 mg. However, long-term treatment, up to 18 years, with H2-blockers isn't associated with iron depletion or anemia in people with normal iron stores. Advise people to maintain adequate dietary iron intake. Supplements aren't necessary unless people have other factors contributing to iron deficiency. For information on foods that are rich in iron, see our chart.
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.
References (4)
- 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
- Skikne BS, Lynch SR, Cook JD. Role of gastric acid in food iron absorption. Gastroenterology 1981;81:1068-71. DOI
- Termanini B, Gibril F, Sutliff VE, et al. Effect of long-term gastric acid suppressive therapy on serum vitamin B12 levels in patients with Zollinger-Ellison syndrome. Am J Med 1998;104:422-30. PubMed
- Stewart CA, Termanini B, Sutliff VE, et al. Iron absorption in patients with Zollinger-Ellison Syndrome treated with long-term gastric acid antisecretory therapy. Aliment Pharmacol Ther 1988;12:83-98.. PubMed
ZINC
Insignificant DepletionH2-BLOCKERS
Limited data suggest inhibition of gastric acid secretion by H2-blockers might reduce absorption of zinc from supplements, but clinically significant zinc depletion hasn't been reported.
What Zinc does & food sources
Zinc supports immune function, wound healing, taste and smell, and many enzyme systems.
Common food sources:
- Meat and shellfish (especially oysters)
- Beans and lentils
- Nuts and seeds
- Whole grains
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
What to discuss with your clinician
Ask about zinc status if you take an associated medication long-term and notice slow wound healing, frequent infections, or taste changes — a clinician can decide whether testing or an empiric plan makes sense.
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
Supplement considerations
Zinc competes with copper for absorption — long-term, higher-dose zinc without medical guidance can cause copper deficiency. Zinc also binds some antibiotics in the gut, so dose timing matters.
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: Keep zinc doses moderate and time them away from interacting medications — ask your pharmacist.
References (1)
- Sturniolo GC, Montino MC, Rossetto L, et al. Inhibition of gastric acid secretion reduces zinc absorption in man. J Am Coll Nutr 1991;10:372. PubMed
VITAMIN B12
Moderate DepletionH2-BLOCKERS
Reduced secretion of gastric acid and pepsin produced by H2-blockers can reduce absorption of protein-bound (dietary), but not supplemental, vitamin B12. This is because gastric acid is needed to release vitamin B12 from protein for absorption. Clinically significant vitamin B12 deficiency and megaloblastic anemia are unlikely, unless H2-blocker therapy is prolonged (2 years or more) or dietary vitamin B12 is low. The odds of developing vitamin B12 deficiency are 25% higher in individuals taking H2-blockers for 2 years or more compared to non-users. Vitamin B12 deficiency is also more likely with prolonged, high-dose H2-blocker therapy than with prolonged, low-dose therapy and in people rendered achlorhydric, which occurs more frequently with proton pump inhibitors than H2-blockers. Vitamin B12 deficiency is expected to diminish upon discontinuation of H2-blocker therapy. For information on foods that are rich in vitamin B12, see our chart.
What Vitamin B12 does & food sources
Vitamin B12 supports red blood cell formation, nerve function, and DNA synthesis.
Common food sources:
- Meat, poultry, and fish
- Eggs and dairy products
- Fortified cereals and nutritional yeast
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
What to discuss with your clinician
If you take an associated medication long-term, ask your healthcare provider whether checking a vitamin B12 level (sometimes with methylmalonic acid) is appropriate — especially if you notice fatigue, numbness, tingling, or memory changes.
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
Supplement considerations
B12 status is easy to check and low levels are usually straightforward to address, so testing before supplementing is often the sensible order. High-dose folic acid can mask a B12 deficiency, which is one reason B12 and folate questions are best sorted out together with your provider.
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: B12 deficiency can look like other conditions — do not self-diagnose from symptoms alone.
References (8)
- 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
- Belaiche J, Zittoun J, Marquet J, et al. Effect of ranitidine on secretion of gastric intrinsic factor and absorption of vitamin B12. Gastroenterol Clin Biol 1983;7:381-4.
- Salom IL, Silvis SE, Doscherholmen A. Effect of cimetidine on the absorption of vitamin B12. Scand J Gastroenterol 1982;17:129-31.
- Ruscin JM, Page RL, Valuck RJ. Vitamin B12 deficiency associated with histamine-2-receptor antagonists and a proton-pump inhibitor. Ann Pharmacother 2002;36:812-6.
- Force RW, Nahata MC. Effect of histamine H2 receptor antagonists on vitamin B12 absorption. Ann Pharmacother 1992;26:1283-6.
- Force RW, Meeker AD, Cady PS, et al. Increased vitamin B12 requirement associated with chronic acid suppression therapy. Ann Pharmacother 2003;37:490-3.
- Lam JR, Schneider JL, Zhao W, et al. Proton pump inhibitor and histamine 2 receptor antagonist use and vitamin B12 deficiency. JAMA 2013;310:2435-42.
- Termanini B, Gibril F, Sutliff VE, et al. Effect of long-term gastric acid suppressive therapy on serum vitamin B12 levels in patients with Zollinger-Ellison syndrome. Am J Med 1998;104:422-30. PubMed
CHROMIUM
Insufficient EvidenceH2-BLOCKERS
H2-blockers increase the gastric pH, which might decrease chromium absorption due to formation of less soluble chromium salts. However, the clinical significance of this is not clear.
References (1)
- 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.
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.
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.
Nutrient depletion FAQs
Can medications really deplete nutrients?
Does an entry in this checker mean I am deficient?
Should I take a supplement if my medication appears here?
What labs should I ask about?
Can supplements interact with my medications?
Where does this information come from, and how is it reviewed?
Not sure what your results mean?
Ask a licensed pharmacist — free, no appointment needed.
Sources & How We Checked
Nutrient depletion records are evidence-graded and sourced from the Natural Medicines database, and are displayed as published with their citations. The plain-English education is written and reviewed by licensed HelloPharmacist pharmacists.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference for drug-induced nutrient depletions, supplements, and interactions — the basis for this checker.
- 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.