Drug-induced nutrient depletion

Neomycin & Nutrient Depletion

Also searched as Mycifradin, Neo-Fradin, Myciguent. What the clinical evidence reports, what it may mean, and what to discuss with your pharmacist.

10Nutrient associations
Insignificant DepletionHighest rating
The bottom line

Neomycin has been associated with depletion of BETA-CAROTENE, BIOTIN, FOLIC ACID and RIBOFLAVIN and 6 more. This does not mean a deficiency will occur — it means these are worth knowing about and, if you take Neomycin long-term, worth raising with your pharmacist or healthcare provider.

Ask a pharmacist about Neomycin Free · usually answered within 24 hours

Take more than one medication? Open the checker with Neomycin pre-loaded and add the rest to see overlapping nutrient signals.

The evidence

Reported nutrient depletions with Neomycin

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.

BETA-CAROTENE

Insignificant Depletion

NEOMYCIN

Neomycin might modestly reduce levels of beta-carotene.

Oral neomycin sulfate in doses of 4-12 grams per day causes malabsorption and can reduce beta-carotene absorption. However, this is not likely to be clinically significant with short-term neomycin use.
Taking Neomycin? A supplement is not needed for most patients. ⓘ
Dr. Brian Staiger, Pharm.D explains

Beta-carotene is a plant pigment your body converts into vitamin A, which supports your vision, immune system, and skin. Neomycin, especially at the high doses sometimes used to prepare the gut before surgery, can interfere with how your intestines absorb nutrients like beta-carotene. That said, this effect is considered insignificant, and short-term use at typical doses is not expected to cause any real problem for most people. No action is needed, but if you have questions about your specific situation, your pharmacist or doctor is a great place to start.

What Vitamin A does & food sources

Vitamin A supports vision, immune function, and skin health.

Common food sources:

  • Liver and fish oils
  • Dairy and eggs
  • Orange and yellow vegetables (as beta-carotene)
  • Leafy greens

HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.

What to discuss with your clinician

Ask your provider before supplementing vitamin A — status testing is not routine, and intake from food plus multivitamins is often already adequate.

HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.

Supplement considerations

Vitamin A is fat-soluble and accumulates; excess is harmful (and dangerous in pregnancy). Prefer food sources unless a clinician advises otherwise.

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 vitamin A in pregnancy or when trying to conceive unless a clinician directs it.

Learn more about this nutrient: Beta-carotene — uses, safety & interactions

References (1)
  1. Jacobson ED, Faloon WW. Malasorptive effects of neomycin in commonly used doses. JAMA 1961;175:187-90.

BIOTIN

Insignificant Depletion

ANTIBIOTIC DRUGS

There is some concern that antibiotic drugs might reduce biotin levels, but this has not been demonstrated in clinical research.
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.
Taking Neomycin? A supplement is not needed for most patients. ⓘ
Dr. Brian Staiger, Pharm.D explains

Biotin is a B vitamin your body needs to convert food into energy and keep your skin, hair, and nails healthy. Neomycin is an antibiotic, and there is a theory that antibiotics can reduce the amount of biotin your gut bacteria produce. In practice, though, those bacteria account for less than a fifth of your daily biotin needs, so this effect is considered insignificant. Most people taking neomycin have nothing to worry about here, but if you have questions about your nutrition while on any antibiotic, your pharmacist or doctor is a good place to start.

Learn more about this nutrient: Biotin — uses, safety & interactions

References (4)
  1. Shils ME, Olson JA, Shike M, Ross AC, eds. Modern Nutrition in Health and Disease. 9th ed. Baltimore, MD: Williams & Wilkins, 1999.
  2. Hill MJ. Intestinal flora and endogenous vitamin synthesis. Eur J Cancer Prev 1997;6:S43-5. PubMed
  3. 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
  4. 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.

FOLIC ACID

Insignificant Depletion

ANTIBIOTIC DRUGS

Theoretically, antibiotics might reduce folate absorption; however, this is not likely to be clinically significant.

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.
Taking Neomycin? A supplement is not needed for most patients. ⓘ
Dr. Brian Staiger, Pharm.D explains

Folic acid is a B vitamin your body needs for healthy cell growth and DNA repair. Neomycin, like other antibiotics, can disrupt the bacteria that normally live in your gut, and those bacteria play a small role in producing and recycling folate. That said, the evidence rates this as insignificant, meaning a real drop in your folic acid levels is quite unlikely in practice. Most people taking neomycin do not need to do anything about this, but if you have questions or take it long-term, your pharmacist or doctor is a good person to ask.

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 (5)
  1. Gorbach SL. Bengt E. Gustafsson memorial lecture. Function of the normal human microflora. Scand J Infect Dis Suppl 1986;49:17-30.
  2. Shils ME, Olson JA, Shike M, Ross AC, eds. Modern Nutrition in Health and Disease. 9th ed. Baltimore, MD: Williams & Wilkins, 1999.
  3. Hill MJ. Intestinal flora and endogenous vitamin synthesis. Eur J Cancer Prev 1997;6:S43-5. PubMed
  4. 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
  5. 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

RIBOFLAVIN

Insignificant Depletion

ANTIBIOTIC DRUGS

Antibiotic drugs might reduce riboflavin levels; however, this is not likely to be clinically significant.
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.
Taking Neomycin? A supplement is not needed for most patients. ⓘ
Dr. Brian Staiger, Pharm.D explains

Riboflavin, which your body uses to turn food into energy and keep skin and nerves healthy, is mostly absorbed from the food you eat rather than made by gut bacteria. Neomycin is an antibiotic, and like other antibiotics it can disrupt the normal bacteria living in your gut that produce small amounts of riboflavin. That said, because dietary sources do most of the work here, this disruption does not appear to make a meaningful dent in your riboflavin levels for most people. This one is rated insignificant, so there is no need to worry or reach for a supplement unless your pharmacist or doctor tells you otherwise.

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

HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.

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.

HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.

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)
  1. Hill MJ. Intestinal flora and endogenous vitamin synthesis. Eur J Cancer Prev 1997;6:S43-5. PubMed
  2. 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
  3. 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 Depletion

ANTIBIOTIC DRUGS

Theoretically, antibiotics might reduce thiamine absorption; however, this is not likely to be clinically significant.
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.
Taking Neomycin? A supplement is not needed for most patients. ⓘ
Dr. Brian Staiger, Pharm.D explains

Thiamine is a B vitamin your body needs to convert food into energy and keep your nerves working properly. Neomycin is an antibiotic taken by mouth, and like most oral antibiotics, it can disrupt the bacteria that normally live in your gut. Those gut bacteria produce a small amount of thiamine, so in theory that process could be interrupted. In practice, though, nearly all the thiamine your body uses comes straight from the food you eat, so this effect is considered insignificant for most people. No supplement is needed for this one, but if you ever have questions about your nutrition while on any antibiotic, your pharmacist is always a good first stop.

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

HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.

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.

HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.

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)
  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 A

Insignificant Depletion

NEOMYCIN

Neomycin might modestly reduce levels of vitamin A.

Neomycin can bind and precipitate fatty acids and bile acids in the gut, reducing fat absorption. There is limited evidence that this can affect fat-soluble vitamin absorption. Single doses of neomycin reduced absorption of large doses (300,000 units) of vitamin A given concurrently. However, there was no change in serum vitamin A levels in adults who took neomycin 1-2 grams/day for 18 weeks for treatment of hyperlipoproteinemia. It's unlikely that neomycin will cause clinically significant vitamin A depletion.
Taking Neomycin? A supplement is not needed for most patients. ⓘ
Dr. Brian Staiger, Pharm.D explains

Vitamin A is something your eyes, immune system, and skin all depend on, and it happens to be a fat-soluble nutrient, meaning your gut needs to absorb it along with dietary fat. Neomycin can interfere with how fat is absorbed in the intestine by latching onto bile acids, which are the compounds that help your gut digest fat in the first place. Because of that, there is a theoretical path by which neomycin could nudge vitamin A absorption down a little. That said, studies in people taking neomycin over several months showed no meaningful drop in blood vitamin A levels, so the evidence rates this as insignificant for most patients. No action is needed for the vast majority of people, but if you have concerns or take neomycin long-term, a quick conversation with your pharmacist is always a reasonable step.

What Vitamin A does & food sources

Vitamin A supports vision, immune function, and skin health.

Common food sources:

  • Liver and fish oils
  • Dairy and eggs
  • Orange and yellow vegetables (as beta-carotene)
  • Leafy greens

HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.

What to discuss with your clinician

Ask your provider before supplementing vitamin A — status testing is not routine, and intake from food plus multivitamins is often already adequate.

HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.

Supplement considerations

Vitamin A is fat-soluble and accumulates; excess is harmful (and dangerous in pregnancy). Prefer food sources unless a clinician advises otherwise.

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 vitamin A in pregnancy or when trying to conceive unless a clinician directs it.

Learn more about this nutrient: Vitamin A — uses, safety & interactions

References (2)
  1. Barrowman JA, Broomhall J, Cannon AM, et al. Impairment of vitamin A absorption by neomycin. Clin Sci 1972;42:17P. PubMed
  2. Schade RWB, van't Laar A, Majoor CLH, Jansen AP. A comparative study of the effects of cholestyramine and neomycin in the treatment of type II hyperlipoproteinemia. Acta Med Scand 1976;199:175-80..

VITAMIN B12

Insignificant Depletion

ANTIBIOTIC DRUGS

Antibiotics might reduce the absorption of vitamin B12, but this effect is unlikely to be clinically significant.

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.
Taking Neomycin? A supplement is not needed for most patients. ⓘ
Dr. Brian Staiger, Pharm.D explains

Vitamin B12 is something your nerves and red blood cells genuinely depend on, so it is worth knowing that neomycin can interfere with how your gut absorbs it. That said, this concern really only comes up with very high doses taken over a long period of time, which is not how most people use this antibiotic. At typical doses, the effect on B12 levels is considered insignificant, and a supplement is not something most patients need to worry about. If you have questions about your specific situation, your pharmacist or doctor is a great 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)
  1. Gorbach SL. Bengt E. Gustafsson memorial lecture. Function of the normal human microflora. Scand J Infect Dis Suppl 1986;49:17-30.
  2. Hill MJ. Intestinal flora and endogenous vitamin synthesis. Eur J Cancer Prev 1997;6:S43-5. PubMed
  3. 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 Depletion

ANTIBIOTIC DRUGS

Theoretically, antibiotics might reduce levels of vitamin B6 in the blood.

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.
Taking Neomycin? A supplement is not needed for most patients. ⓘ
Dr. Brian Staiger, Pharm.D explains

Vitamin B6 is something your body counts on for energy metabolism, brain function, and making red blood cells. There has been some speculation that antibiotics like neomycin, by wiping out bacteria in the gut, could reduce any B6 that those bacteria might produce. In practice, though, gut bacteria do not appear to be a meaningful source of B6 for people, so this concern has not held up. The evidence rating here is insignificant, meaning supplementation is not considered necessary for most people taking neomycin.

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.

HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.

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)
  1. Gorbach SL. Bengt E. Gustafsson memorial lecture. Function of the normal human microflora. Scand J Infect Dis Suppl 1986;49:17-30.
  2. Hill MJ. Intestinal flora and endogenous vitamin synthesis. Eur J Cancer Prev 1997;6:S43-5. PubMed
  3. 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.

MAGNESIUM

Moderate Depletion

AMINOGLYCOSIDE ANTIBIOTICS

Increased urinary magnesium loss occurs with nephrotoxicity caused by aminoglycosides.

Nephrotoxicity caused by aminoglycosides may lead to increased urinary losses of various electrolytes, including magnesium. Monitor patients closely to detect declining renal function and electrolyte disturbances. The aminoglycoside may need to be discontinued and intravenous electrolyte replacement given.
Taking Neomycin? Monitor for depletion; a supplement is needed for some patients. ⓘ
Dr. Brian Staiger, Pharm.D explains

Magnesium helps keep your muscles, nerves, and heart rhythm working properly, so your body needs to hold onto it. Neomycin belongs to a family of antibiotics called aminoglycosides, and one known risk with these drugs is that they can be hard on the kidneys. When the kidneys are stressed this way, they may lose their ability to hold magnesium back, letting too much spill out in the urine. This is rated a moderate concern, meaning your care team will likely keep an eye on your kidney function and magnesium levels while you are on this medication, and some patients do end up needing a supplement or extra support. If you have questions about what to watch for, your pharmacist or doctor is the right person to ask.

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

HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.

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.

HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.

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)
  1. L'Hommedieu CS, Nicholas D, Armes DA, et al. Potentiation of magnesium sulfate--induced neuromuscular weakness by gentamicin, tobramycin, and amikacin. J Pediatr 1983;102:629-31..

VITAMIN K

Moderate Depletion

ANTIBIOTIC DRUGS

Prolonged therapy with antibiotic drugs might decrease levels of vitamin K.

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.
Taking Neomycin? Monitor for depletion; a supplement is needed for some patients. ⓘ
Dr. Brian Staiger, Pharm.D explains

Vitamin K is something your blood clotting system depends on to work properly. Neomycin is an antibiotic taken by mouth, and like other oral antibiotics used for longer stretches, it can wipe out the gut bacteria that normally produce a portion of your body's vitamin K supply. This is rated as a moderate concern, meaning it is worth paying attention to, especially if your diet is low in leafy greens or therapy lasts more than a week or two. If you are using neomycin longer term, it is worth a conversation with your pharmacist or doctor about whether monitoring or a supplement makes sense for you.

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

HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.

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.

HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.

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)
  1. Hill MJ. Intestinal flora and endogenous vitamin synthesis. Eur J Cancer Prev 1997;6:S43-5. PubMed
  2. 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.
  3. 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.
  4. 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.
  5. Haubenstock A, Schmidt P, Zazgornik J, Balcke P, Kopsa H. Hypoprothrombobinaemic bleeding associated with ceftriaxone. Lancet 1983;1:1215-6.
  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
  7. Bhat RV, Deshmukh CT. A study of Vitamin K status in children on prolonged antibiotic therapy. Indian Pediatr 2003;40:36-40.
  8. Sattler FR, Weitekamp MR, Ballard JO. Potential for bleeding with the new beta-lactam antibiotics. Ann Intern Med 1986;105:924-31. PubMed
Important

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.
Understand the basics

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.

Common questions

Neomycin & nutrients: FAQs

Does Neomycin deplete BETA-CAROTENE?
Neomycin has been associated with lower BETA-CAROTENE levels in the clinical literature — see the evidence rating and details above. An association is not a guarantee: dose, duration, diet, and your own health all matter. If you take Neomycin long-term, ask your healthcare provider whether checking your BETA-CAROTENE status is appropriate.
Should I take a supplement because I take Neomycin?
Not automatically. The right first step is usually a conversation with your pharmacist or provider — they can weigh your dose and duration, decide whether testing makes sense, and recommend food-first strategies or a supplement if genuinely needed. Some supplements can interact with medications, so do not add one without checking.
Should I stop taking Neomycin?
No — never stop a prescribed medication because of a nutrient association. Neomycin is prescribed for good reasons, and nutrient considerations are usually manageable with monitoring or diet. Any change to your medication belongs in a conversation with your prescriber.
Where does this information come from?
The depletion records come from the Natural Medicines (Therapeutic Research Center) database — an evidence-graded clinical reference — and are displayed as published, with their citations. The plain-English context is written and reviewed by licensed HelloPharmacist pharmacists.

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Sources

Sources & How We Checked

Nutrient depletion records for Neomycin are evidence-graded and sourced from the Natural Medicines database, and are displayed as published with their citations.

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