Tetracycline & Nutrient Depletion
Also searched as Sumycin, Sumycin 250, Tetrex BID. What the clinical evidence reports, what it may mean, and what to discuss with your pharmacist.
Tetracycline has been associated with depletion of BIOTIN, CALCIUM, FOLIC ACID and IRON and 7 more. This does not mean a deficiency will occur — it means these are worth knowing about and, if you take Tetracycline long-term, worth raising with your pharmacist or healthcare provider.
Take more than one medication? Open the checker with Tetracycline pre-loaded and add the rest to see overlapping nutrient signals.
Reported nutrient depletions with Tetracycline
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.
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BIOTIN
Insignificant DepletionANTIBIOTIC DRUGS
Interference with the normal gastrointestinal flora by antibiotics may reduce bacterial synthesis of biotin. Although some bacterially-synthesized biotin can be absorbed from the lower intestine, this appears to contribute less than 20% of a person's daily requirement for biotin. Therefore it's unlikely that antibiotics would contribute to biotin deficiency.
Biotin is a B vitamin your body uses to convert food into energy and keep your skin, hair, and nails healthy. The concern with tetracycline and biotin is that antibiotics can reduce the bacteria living in your gut, and those bacteria naturally produce a small amount of biotin. That said, gut bacteria account for less than 20% of your daily biotin needs, so this theoretical dip is considered insignificant by the research. Most people taking tetracycline do not need to worry about this or take a biotin supplement, but if you have questions about your specific situation, your pharmacist or doctor is a great resource.
Learn more about this nutrient: Biotin — uses, safety & interactions
References (4)
- Shils ME, Olson JA, Shike M, Ross AC, eds. Modern Nutrition in Health and Disease. 9th ed. Baltimore, MD: Williams & Wilkins, 1999.
- Hill MJ. Intestinal flora and endogenous vitamin synthesis. Eur J Cancer Prev 1997;6:S43-5. PubMed
- Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
- Grundy WE, Freed M, Johnson H.C., et al. The effect of phthalylsulfathiazole (sulfathalidine) on the excretion of B-vitamins by normal adults. Arch Biochem. 1947 Nov;15:187-94.
CALCIUM
Insignificant DepletionTETRACYCLINE ANTIBIOTICS
Tetracyclines form complexes with calcium in the gastrointestinal tract, which could reduce absorption of both the tetracycline and calcium if taken at the same time. Significant effects are unlikely when tetracyclines are taken at least two hours before, or four to six hours after, calcium supplements or calcium-containing foods.
Calcium, which your bones, muscles, and nerves all depend on, can physically latch onto tetracycline in the stomach and intestines, forming a combined molecule that your body struggles to absorb. The good news is that timing solves the problem: taken at least two hours apart from dairy or calcium supplements, tetracycline is very unlikely to pull your calcium levels down in any meaningful way. The rating here is insignificant, meaning most people on a short antibiotic course have nothing to worry about. If you have any questions about spacing your doses correctly, your pharmacist can walk you through it.
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
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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.
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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.
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Caution: Very high calcium intake has its own risks (kidney stones in susceptible people) — more is not better.
Learn more about this nutrient: Calcium — uses, safety & interactions
References (1)
- Murry JJ, Healy MD. Drug-mineral interactions: a new responsibility for the hospital dietician. J Am Diet Assoc 1991;91:66-73.
FOLIC ACID
Insignificant DepletionANTIBIOTIC DRUGS
Antibiotic therapy can disrupt the normal gastrointestinal (GI) flora, interfering with enterohepatic recirculation (reabsorption) of folic acid. The normal GI flora also synthesizes and consumes folic acid, which may also be disrupted by antibiotics. Folic acid synthesized by GI bacteria can be absorbed in the large intestine, but the amount synthesized and absorbed is variable. For instance, it can depend on dietary fiber intake and gastric pH; hypochlorhydria causes bacterial overgrowth and increased folate synthesis. In most people it's unlikely that a course of antibiotics will reduce folic acid levels significantly, and therefore supplements are unnecessary. For information on foods that are rich in folate, see our chart.
Folic acid is a B vitamin your body needs to build healthy cells and support normal DNA function. Tetracycline can shift the balance of bacteria living in your gut, and since those bacteria play a small role in producing and recycling folate, there is a theoretical possibility that levels could be nudged lower. That said, the evidence rates this as insignificant, meaning a typical course of tetracycline is very unlikely to affect your folate in any meaningful way and most people do not need a supplement for this reason. If you have specific concerns or take tetracycline long-term, a quick conversation with your pharmacist or doctor can put your mind at ease.
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
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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.
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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.
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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 (5)
- Gorbach SL. Bengt E. Gustafsson memorial lecture. Function of the normal human microflora. Scand J Infect Dis Suppl 1986;49:17-30.
- Shils ME, Olson JA, Shike M, Ross AC, eds. Modern Nutrition in Health and Disease. 9th ed. Baltimore, MD: Williams & Wilkins, 1999.
- Hill MJ. Intestinal flora and endogenous vitamin synthesis. Eur J Cancer Prev 1997;6:S43-5. PubMed
- Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
- Russell RM, Krasinski SD, Samloff IM, et al. Folic acid malabsorption in atrophic gastritis: possible compensation by bacterial folate synthesis. Gastroenterology 1986;91:1476-82. PubMed
IRON
Insignificant DepletionTETRACYCLINE ANTIBIOTICS
Tetracyclines form complexes with iron in the GI tract, reducing absorption of both the tetracycline and iron if taken at the same time. Significant effects on iron levels are unlikely when tetracyclines are taken at least two hours before or after iron supplements or iron-containing foods.
Iron is something your body needs to carry oxygen in the blood and keep your energy up. Here is the interesting thing about tetracycline: it does not drain iron from your body the way some drugs do. Instead, if you take iron and tetracycline at the same time, the two can latch onto each other in your stomach and reduce how well either one is absorbed. The good news is that spacing them at least two hours apart is enough to sidestep that interaction, and for most people taking tetracycline, iron levels are not a real concern. No supplement is needed for most patients, but if you have questions about timing your doses, your pharmacist is a great place to start.
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)
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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.
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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.
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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)
- Murry JJ, Healy MD. Drug-mineral interactions: a new responsibility for the hospital dietician. J Am Diet Assoc 1991;91:66-73.
- Leyden JJ. Absorption of minocycline hydrochloride and tetracycline hydrochloride. Effect of food, milk, and iron. J Am Acad Dermatol 1985;12(2 Pt 1):308-12. PubMed
- Neuvonen PJ, Pentikainen PJ, Gothoni G. Inhibition of iron absorption by tetracycline [letter]. Br J Clin Pharmacol 1975;2:94-6. PubMed
MAGNESIUM
Insignificant DepletionTETRACYCLINE ANTIBIOTICS
Tetracyclines form complexes with magnesium in the GI tract, which could reduce absorption of both the tetracycline and magnesium. Significant effects on magnesium levels are unlikely when tetracyclines are taken on an empty stomach, 1 hour before or 2 hours after magnesium supplements.
Magnesium helps your muscles contract, keeps your heart rhythm steady, and supports hundreds of chemical reactions throughout the body. Here is the interesting thing about tetracycline: it can physically latch onto magnesium in the gut, forming a combined complex that neither absorbs well. In practice, though, this interaction is rated insignificant, meaning it rarely causes a real drop in magnesium levels for most people. If you take tetracycline on an empty stomach and keep magnesium supplements spaced a couple of hours apart, there is generally nothing to worry about, but feel free to ask your pharmacist if you have any questions.
What Magnesium does & food sources
Magnesium is involved in muscle and nerve function, heart rhythm, blood sugar control, and bone health.
Common food sources:
- Nuts and seeds (almonds, pumpkin seeds)
- Whole grains
- Leafy green vegetables
- Beans and legumes
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What to discuss with your clinician
Ask whether a magnesium level is worth checking if you take an associated medication long-term — particularly with symptoms like muscle cramps, twitching, or palpitations. Blood levels do not always reflect total body stores, which is worth discussing too.
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Supplement considerations
Magnesium supplements come in many forms and can cause loose stools at higher doses. They can also bind some medications in the gut (certain antibiotics, thyroid medication), so timing matters — check with your pharmacist.
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: Magnesium supplementation can be risky in kidney disease, where magnesium can accumulate — always check with a clinician first if your kidney function is reduced.
Learn more about this nutrient: Magnesium — uses, safety & interactions
References (1)
- Murry JJ, Healy MD. Drug-mineral interactions: a new responsibility for the hospital dietician. J Am Diet Assoc 1991;91:66-73.
RIBOFLAVIN
Insignificant DepletionANTIBIOTIC DRUGS
Interference with the normal gastrointestinal flora by antibiotics may reduce bacterial synthesis of riboflavin. However, this synthesis doesn't seem to significantly contribute to the body's supply of riboflavin, which is primarily obtained from dietary sources. Riboflavin supplements aren't necessary during antibiotic therapy.
Riboflavin (vitamin B2) helps your body turn food into energy and keeps your skin, eyes, and nerves working well. Tetracycline and other antibiotics can disrupt the friendly bacteria living in your gut, and those bacteria do produce small amounts of riboflavin on their own. That said, most of what your body actually needs comes from the food you eat, so this particular effect is considered insignificant for most people. No supplement is needed during a typical course of tetracycline, but if you have questions about your diet or vitamin intake, your pharmacist or doctor is a great place to start.
What Vitamin B2 (riboflavin) does & food sources
Riboflavin helps the body produce energy and process other B vitamins.
Common food sources:
- Dairy products and eggs
- Lean meats
- Fortified grains
- Green vegetables
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What to discuss with your clinician
Deficiency is uncommon with a varied diet; ask your provider if you have persistent mouth-corner cracking, sore tongue, or unexplained fatigue on a long-term associated medication.
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Supplement considerations
Riboflavin is water-soluble and excess is excreted (it turns urine bright yellow — harmless).
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.
Learn more about this nutrient: Riboflavin — uses, safety & interactions
References (3)
- Hill MJ. Intestinal flora and endogenous vitamin synthesis. Eur J Cancer Prev 1997;6:S43-5. PubMed
- Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
- McCormick DB. Riboflavin. In: Shils ME, Olson JA, Shike M, Ross AC, eds. Modern Nutrition in Health and Disease. 9th ed. Baltimore, MD: Williams & Wilkins, 1999. pg.391-9.
THIAMINE
Insignificant DepletionANTIBIOTIC DRUGS
Interference with the normal gastrointestinal flora by antibiotics may reduce bacterial synthesis of thiamine. However, the majority of the daily thiamine requirement is obtained from the diet, rather than synthesis by the GI flora. Therefore this isn't likely to be clinically significant, and thiamine supplements aren't necessary.
Thiamine is a B vitamin your body needs to turn food into energy and keep your nerves working well. Tetracycline is an antibiotic, and there is a theoretical idea that it could reduce the gut bacteria that normally make small amounts of thiamine. In practice, though, your diet supplies the vast majority of the thiamine you need, so this is not considered clinically meaningful. Most people taking tetracycline do not need to do anything about this, but your pharmacist is always a good resource if you have questions.
What Vitamin B1 (thiamine) does & food sources
Thiamine helps convert food into energy and is essential for nerve and heart function.
Common food sources:
- Whole grains and fortified cereals
- Pork
- Beans and lentils
- Nuts and seeds
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What to discuss with your clinician
Ask about thiamine if you take an associated medication (for example, a long-term loop diuretic in heart failure) and have symptoms like fatigue or worsening heart failure control — this is an area your care team can weigh.
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Supplement considerations
Thiamine is water-soluble and generally low-risk, but supplementing to treat a suspected problem should still be clinician-guided so the real cause is not missed.
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.
Learn more about this nutrient: Thiamine — uses, safety & interactions
References (1)
- Goldin BR, Lichtenstein AH, Gorbach SL. Nutritional and metabolic roles of intestinal flora. In: Shils ME, Olson JA, Shike M, eds. Modern Nutrition in Health and Disease, 8th ed. Malvern, PA: Lea & Febiger, 1994.
VITAMIN B12
Insignificant DepletionANTIBIOTIC DRUGS
Disruption of the normal gastrointestinal (GI) flora may interrupt enterohepatic recirculation of vitamin B12 and increase fecal excretion. Vitamin B12 is also synthesized by the GI flora, but mainly in the colon where absorption is poor. The majority of bacterially-synthesized vitamin B12 is therefore excreted in the feces and does not significantly contribute to the body's store of vitamin B12. The effects of antibiotics on gastrointestinal bacteria are unlikely to have clinically significant effects on vitamin B12 levels. In people with bacterial overgrowth of the small bowel, antibiotics such as metronidazole (Flagyl) can actually improve vitamin B12 status. An increased bacterial load can bind significant amounts of vitamin B12 in the gut, preventing its absorption.
Vitamin B12 is something your nerves and red blood cells genuinely depend on, so it is worth knowing that tetracycline can alter the bacteria living in your gut. Those bacteria play a small role in how B12 moves through your digestive system, and disrupting them may nudge fecal excretion of B12 upward. That said, the evidence puts this squarely in the 'not clinically meaningful' category for most people, and a supplement is not considered necessary for the typical patient taking tetracycline. If you have any personal concerns, your pharmacist or doctor is the right person to ask.
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.
Learn more about this nutrient: Vitamin B12 — uses, safety & interactions
References (3)
- Gorbach SL. Bengt E. Gustafsson memorial lecture. Function of the normal human microflora. Scand J Infect Dis Suppl 1986;49:17-30.
- Hill MJ. Intestinal flora and endogenous vitamin synthesis. Eur J Cancer Prev 1997;6:S43-5. PubMed
- Goldin BR, Lichtenstein AH, Gorbach SL. Nutritional and metabolic roles of intestinal flora. In: Shils ME, Olson JA, Shike M, eds. Modern Nutrition in Health and Disease, 8th ed. Malvern, PA: Lea & Febiger, 1994.
VITAMIN B6
Insignificant DepletionANTIBIOTIC DRUGS
Some sources suggest that destruction of the normal gastrointestinal flora by antibiotics can decrease production and plasma levels of vitamin B6. However, there is no evidence that the gastrointestinal flora is a significant source of vitamin B6 in humans. Supplementation with vitamin B6 is not necessary during antibiotic therapy. For information on foods that are rich in vitamin B6, see our chart.
Vitamin B6 helps your body make energy from food and keeps your nerves and immune system working properly. There has been some speculation that tetracycline, like other antibiotics, could reduce B6 levels by disrupting the bacteria that live in your gut, since those bacteria can produce small amounts of B6. In practice, though, researchers do not believe gut bacteria contribute enough B6 to matter, and there is no real-world evidence that this becomes a problem. This one is rated insignificant, so the vast majority of people taking tetracycline do not need to worry about it or take a supplement.
What Vitamin B6 does & food sources
Vitamin B6 is involved in protein metabolism, neurotransmitter production, and red blood cell formation.
Common food sources:
- Poultry and fish
- Potatoes and starchy vegetables
- Bananas
- Fortified cereals
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
What to discuss with your clinician
With some medications (for example, isoniazid), B6 is intentionally co-prescribed — follow your prescriber's plan. Otherwise, ask whether testing or supplementation is appropriate if you have symptoms like numbness or tingling.
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Supplement considerations
Paradoxically, long-term high-dose B6 can itself cause nerve symptoms — this is a nutrient where more is definitely not better.
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: Avoid high-dose B6 without medical guidance; sustained high intakes can cause neuropathy.
Learn more about this nutrient: Vitamin B6 — uses, safety & interactions
References (3)
- Gorbach SL. Bengt E. Gustafsson memorial lecture. Function of the normal human microflora. Scand J Infect Dis Suppl 1986;49:17-30.
- Hill MJ. Intestinal flora and endogenous vitamin synthesis. Eur J Cancer Prev 1997;6:S43-5. PubMed
- Goldin BR, Lichtenstein AH, Gorbach SL. Nutritional and metabolic roles of intestinal flora. In: Shils ME, Olson JA, Shike M, eds. Modern Nutrition in Health and Disease, 8th ed. Malvern, PA: Lea & Febiger, 1994.
ZINC
Insignificant DepletionTETRACYCLINE ANTIBIOTICS
Clinical research shows that tetracyclines such as tetracycline, demeclocycline, and minocycline, form complexes with zinc in the gastrointestinal tract, which can reduce absorption of both dietary and supplemental zinc. Doxycycline doesn't seem to cause this interaction. Advise patients to take tetracyclines at least 2 hours before, or 4-6 hours after, zinc supplements. Effects of tetracyclines on dietary zinc absorption aren't likely to be clinically significant except in people with other risk factors for zinc deficiency who take tetracyclines for several months.
Zinc is a mineral your immune system, wound healing, and cell growth all depend on. Tetracycline can latch onto zinc in the gut and form a bound complex, which may reduce how much zinc gets absorbed from food or supplements. That said, the evidence rates this as insignificant for most people, meaning everyday dietary zinc is unlikely to be a real concern unless you have other risk factors for low zinc and are taking tetracycline for several months. If that sounds like your situation, just bring it up with your pharmacist or doctor.
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
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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.
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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.
Learn more about this nutrient: Zinc — uses, safety & interactions
References (4)
- Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
- Neuvonen PJ. Interactions with the absorption of tetracyclines. Drugs 1976;11:45-54.. PubMed
- Weismann K. Chelating drugs and zinc. Dan Med Bull 1986;33:208-11.
- Penttila O, Hurme H, Neuvonen PJ. Effect of zinc sulfate on the absorption of tetracycline and doxycycline in man. Eur J Clin Pharmacol 1975;9:131-4.
VITAMIN K
Moderate DepletionANTIBIOTIC DRUGS
Vitamin K produced by intestinal bacteria is absorbed from the ileum. This contribution to overall vitamin K status is unclear, and likely varies. Destruction of vitamin K-producing bacteria by antibiotics can sometimes lead to vitamin K deficiency, prolonging clotting times and increasing bleeding risk. It's suggested that antibiotics such as cefamandole that are secreted into the bile in large amounts have a greater effect on vitamin K-producing bacteria. Also, some cephalosporins have a methylthiotetrazole side chain that may interfere with vitamin K activity, directly inhibiting clotting factor production in the liver. These cephalosporins include cefamandole, cefoperazone, cefmetazole, and cefotetan. This interaction is most likely to occur with prolonged antibiotic therapy (10 days or more) in people with poor dietary vitamin K intake. Vitamin K supplements aren't necessary for otherwise healthy people taking short courses of antibiotics. For information on foods that are rich in vitamin K, see our chart.
Vitamin K is something your body needs to form blood clots and stop bleeding properly. Your gut bacteria normally make a meaningful share of your daily vitamin K, but tetracycline can wipe out some of those bacteria, leaving less of the vitamin available. This is rated as a moderate concern, so it matters most if you are on a long course (roughly ten days or more) and your diet is already low in vitamin K-rich foods like leafy greens. If that sounds like your situation, it is worth a quick conversation with your pharmacist or doctor about whether anything needs to be monitored.
What Vitamin K does & food sources
Vitamin K is required for normal blood clotting and contributes to bone health.
Common food sources:
- Leafy green vegetables (spinach, kale, broccoli)
- Vegetable oils
- Fermented foods like natto
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What to discuss with your clinician
If you take warfarin, vitamin K intake is a central part of your therapy — consistency matters more than avoidance. Discuss any planned change in vitamin K intake (diet or supplements) with the clinic that manages your INR.
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Supplement considerations
Never start or stop a vitamin K supplement on your own if you take warfarin — it directly changes how the medication works.
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: Vitamin K interacts with warfarin: keep intake consistent and involve your anticoagulation clinic in any change.
Learn more about this nutrient: Vitamin K — uses, safety & interactions
References (8)
- Hill MJ. Intestinal flora and endogenous vitamin synthesis. Eur J Cancer Prev 1997;6:S43-5. PubMed
- Conly JM, Stein K, Worobetz L, Rutledge-Harding S. The contribution of vitamin K2 (menaquinones) produced by the intestinal microflora to human nutritional requirements for vitamin K. Am J Gastroenterol 1994;89:915-23.
- Goldin BR, Lichtenstein AH, Gorbach SL. Nutritional and metabolic roles of intestinal flora. In: Shils ME, Olson JA, Shike M, eds. Modern Nutrition in Health and Disease, 8th ed. Malvern, PA: Lea & Febiger, 1994.
- 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.
- Haubenstock A, Schmidt P, Zazgornik J, Balcke P, Kopsa H. Hypoprothrombobinaemic bleeding associated with ceftriaxone. Lancet 1983;1:1215-6.
- Hooper CA, Haney BB, Stone HH. Gastrointestinal bleeding due to vitamin K deficiency in patients on parenteral cefamandole. Lancet 1980;1:39-40. PubMed
- Bhat RV, Deshmukh CT. A study of Vitamin K status in children on prolonged antibiotic therapy. Indian Pediatr 2003;40:36-40.
- Sattler FR, Weitekamp MR, Ballard JO. Potential for bleeding with the new beta-lactam antibiotics. Ann Intern Med 1986;105:924-31. PubMed
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 Tetracycline
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.
Tetracycline & nutrients: FAQs
Does Tetracycline deplete BIOTIN?
Should I take a supplement because I take Tetracycline?
Should I stop taking Tetracycline?
Where does this information come from?
Questions about Tetracycline and your nutrition?
Ask a licensed pharmacist — free, no appointment needed.
Sources & How We Checked
Nutrient depletion records for Tetracycline 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.