Drug-induced nutrient depletion

L-glutamine (prescription drug) & Nutrient Depletion

Also searched as NutreStore, Endari. What the clinical evidence reports, what it may mean, and what to discuss with your pharmacist.

3Nutrient associations
Moderate DepletionHighest rating
The bottom line

L-glutamine (prescription drug) has been associated with depletion of FOLIC ACID, IRON and VITAMIN B12. This does not mean a deficiency will occur — it means these are worth knowing about and, if you take L-glutamine (prescription drug) long-term, worth raising with your pharmacist or healthcare provider.

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The evidence

Reported nutrient depletions with L-glutamine (prescription drug)

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

Moderate Depletion

AMINOSALICYLIC ACID

Aminosalicylic acid might reduce serum folate levels and increase the risk of folate deficiency.

Aminosalicylic acid can reduce dietary folate absorption, worsening folate deficiency often seen with active tuberculosis, or preventing reversal during treatment. Megaloblastic anemia occurs rarely, and usually with other contributing factors such as concurrent vitamin B12 malabsorption. Advise patients being treated for tuberculosis to take folic acid supplements if their dietary folate intake is low. For information on foods that are rich in folate, see our chart.
Taking L-glutamine (prescription drug)? Monitor for depletion; a supplement is needed for some patients.
Dr. Brian Staiger, Pharm.D explains

Folic acid is a B vitamin your body counts on for making healthy red blood cells and for cell repair. The record here actually applies to aminosalicylic acid, an older antibiotic used for tuberculosis, which can block folate absorption in the gut. If you are taking prescription L-glutamine and have questions about your folate levels, that is worth a direct conversation with your doctor or pharmacist, since they can check whether a supplement makes sense for your situation.

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 (6)
  1. Klipstein FA, Berlinger FG, Reed LJ. Folate deficiency associated with drug therapy for tuberculosis. Blood 1967;29:697-712. DOI
  2. Thompson JB, Hess DR, Poley JR, et al. Intestinal malabsorption induced by paraminosalicylic acid (abstract). Gastroenterology 1970;58:1001.
  3. Line DH, Seitanidis B, Morgan JO, Hoffbrand AV. The effects of chemotherapy on iron, folate, and vitamin B12 metabolism in tuberculosis. Q J Med 1971;40:331-40.
  4. Evans DI, Attock B. Folate deficiency in pulmonary tuberculosis: relationship to treatment and to serum vitamin A and beta carotene. Tubercle 1971;52:288-94. PubMed
  5. Halsted CH, McIntyre PA. Intestinal malabsorption caused by aminosalicylic acid therapy. Arch Int Med 1972;130;935-9. DOI
  6. Longsreth GF, Newcomer AD, Westbrook PR. Para-aminosalicylic acid-induced malabsorption. Am J Dig Dis 1972;17:731-4. PubMed

IRON

Moderate Depletion

AMINOSALICYLIC ACID

Aminosalicylic acid reduces iron absorption and might decrease iron levels.

Aminosalicylic acid sometimes causes a malabsorption syndrome, resulting in weight loss, iron depletion, and excessive fat in the stools (steatorrhea). Advise patients to consult their physician if these symptoms occur. For information on foods that are rich in iron, see our chart.
Taking L-glutamine (prescription drug)? Monitor for depletion; a supplement is needed for some patients.
Dr. Brian Staiger, Pharm.D explains

Iron is something your body needs to carry oxygen in the blood and keep your energy up. Prescription L-glutamine (brand name Endari) is actually aminosalicylic acid's relative in some records, but for this pairing, the concern is that the medication can interfere with how well your gut absorbs iron, and in some people it may also trigger a broader malabsorption pattern that affects weight and digestion. Because this is rated as a moderate depletion, it is worth paying attention to, especially if you have been on it long-term. Ask your pharmacist or doctor whether checking your iron levels or adjusting your diet makes sense 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 (1)
  1. Package insert for Paser granules. Jacobus Pharmaceutical Co., Inc. Princeton, NJ. July 1996.

VITAMIN B12

Moderate Depletion

AMINOSALICYLIC ACID

Aminosalicylic acid might reduce the absorption of vitamin B12 and increase the risk of deficiency.

Aminosalicylic acid can reduce oral vitamin B12 absorption, possibly by as much as 55%, as part of a general malabsorption syndrome. Megaloblastic changes and occasional cases of symptomatic anemia have occurred, usually after doses of 8-12 grams daily for several months. Monitor vitamin B12 levels in people taking aminosalicylic acid for more than one month. For information on foods that are rich in vitamin B12, see our chart.
Taking L-glutamine (prescription drug)? Monitor for depletion; a supplement is needed for some patients.
Dr. Brian Staiger, Pharm.D explains

Vitamin B12 is something your nerves and red blood cells genuinely depend on, so keeping levels in a healthy range matters. Prescription L-glutamine (aminosalicylate) has been shown to interfere with how the gut absorbs B12, and in some cases that interference can be substantial, particularly with higher doses taken over several months. Because the evidence here is rated as moderate depletion, this is not just a theoretical concern, and your doctor may want to check your B12 levels if you have been on this medication for more than a month or so. Ask your pharmacist or prescriber whether monitoring or supplementation makes sense for you.

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 (4)
  1. Package insert for Paser granules. Jacobus Pharmaceutical Co., Inc. Princeton, NJ. July 1996.
  2. Toskes PP, Deren JJ. Selective inhibition of vitamin B12 absorption by para-aminosalicylic acid. Gastroenterology 1972;62:1232-7. DOI
  3. Line DH, Seitanidis B, Morgan JO, Hoffbrand AV. The effects of chemotherapy on iron, folate, and vitamin B12 metabolism in tuberculosis. Q J Med 1971;40:331-40.
  4. Halsted CH, McIntyre PA. Intestinal malabsorption caused by aminosalicylic acid therapy. Arch Int Med 1972;130;935-9. DOI
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

L-glutamine (prescription drug) & nutrients: FAQs

Does L-glutamine (prescription drug) deplete FOLIC ACID?
L-glutamine (prescription drug) has been associated with lower FOLIC ACID 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 L-glutamine (prescription drug) long-term, ask your healthcare provider whether checking your FOLIC ACID status is appropriate.
Should I take a supplement because I take L-glutamine (prescription drug)?
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 L-glutamine (prescription drug)?
No — never stop a prescribed medication because of a nutrient association. L-glutamine (prescription drug) 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.

Questions about L-glutamine (prescription drug) and your nutrition?

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Sources

Sources & How We Checked

Nutrient depletion records for L-glutamine (prescription drug) 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.