Interactions on record — worth a quick check against your medications. Check your meds →
Dietary supplement

RepleteExtra Ingredients & Drug Interactions

by CHK Nutrition

RepleteExtra label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking RepleteExtra against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

RepleteExtra is a dietary supplement by CHK Nutrition with 3 active ingredients. Its ingredients are commonly taken for mental focus and alertness, coping with stress, fatigue and sleep loss.Based on those ingredients, 423 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are 5-HTP, Folic Acid, L-Tyrosine. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against RepleteExtra by CHK Nutrition

Ask about any prescription or over-the-counter medication and we check it for interactions with RepleteExtra by CHK Nutrition — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of RepleteExtra by CHK Nutrition

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Sep 10, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 3 of its 3 active ingredients.
  • “Folate” is listed as a grouped ingredient — the label gives one combined amount (680 mcg DFE) without saying how much of each component you get.

RepleteExtra contains three active ingredients. Folic acid is a B vitamin used to treat folate deficiency and help prevent birth defects.

L-tyrosine is an amino acid, and 5-HTP is a compound derived from the amino acid tryptophan—both support mood and cognitive function. The product also contains inactive ingredients (vegetable capsule, rice flour, cellulose, silicon dioxide, and magnesium stearate) that serve as fillers and binders.

Does it work?

Strong evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed

This product doesn't appear to be marketed for a specific use, so we graded its ingredients' overall clinical evidence instead.

Strong

Strong clinical evidence supports its ingredients for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredients' overall clinical evidence instead.
  • On file: Folate deficiency — rated "Effective" (Folic Acid) (Natural Medicines).
  • On file: Phenylketonuria (PKU) — rated "Effective" (Tyrosine) (Natural Medicines).
  • On file: Methotrexate toxicity — rated "Likely Effective" (Folic Acid) (Natural Medicines).
  • On file: Neural tube birth defects — rated "Likely Effective" (Folic Acid) (Natural Medicines).
  • On file: Depression — rated "Possibly Effective" (5-htp) (Natural Medicines).

Folic acid in this product is effective for folate deficiency and likely effective for preventing methotrexate toxicity and neural tube birth defects. It's possibly effective for depression, phenytoin-induced gingival hyperplasia (overgrowth of gum tissue), and cognitive impairment.

L-tyrosine is effective for phenylketonuria (PKU) and possibly effective for cognitive function and memory, though it's rated possibly ineffective for athletic performance. 5-HTP is possibly effective for depression but rated possibly ineffective for Down syndrome and insufficient evidence exists for its use in Alzheimer disease, ADHD, or cerebellar ataxia.

The evidence, ingredient by ingredient Tyrosine Folic Acid 5-htp

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 3 of the 3 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 3 of 3.
  • General safety write-ups exist for 3 of 3.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Folic acid is generally well tolerated at recommended doses for most adults and is considered safe during pregnancy at standard prenatal doses to help prevent birth defects, though late-pregnancy use has been associated with increased childhood asthma risk in population studies. It's safe while breastfeeding at normal doses.

At higher doses (5 mg daily or more), side effects include abdominal cramps, diarrhea, and rash; at 15 mg daily, bitter taste, confusion, nausea, and sleep disturbances have been reported. Rare serious effects include seizures, liver injury, and cardiovascular complications with long-term use.

L-tyrosine is generally well tolerated in healthy adults but talk with your healthcare provider before regular use—not enough safety data exists for pregnancy or breastfeeding, so avoid supplemental doses unless a doctor advises otherwise. Common side effects are fatigue, headache, heartburn, and nausea.

5-HTP is well tolerated short-term but carries a caution label: avoid during pregnancy and breastfeeding due to insufficient safety information. Common side effects include nausea, diarrhea, headache, drowsiness, and fatigue; rare serious effects include hallucinations, mania, and aggression.

Side effects, ingredient by ingredient Tyrosine Folic Acid 5-htp

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 3 of the 3 matched ingredients can interact with medications — 5-htp, Folic Acid, Tyrosine.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: Parkinson's medications.
  • For scale: 423 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking RepleteExtra, check with your doctor or pharmacist if you take seizure medications (phenobarbital, phenytoin, or primidone), as folic acid can worsen seizure control. Also confirm if you're on levodopa for Parkinson's disease, thyroid hormones, antidepressants or other serotonergic drugs, sedating medications, carbidopa, cancer medications like methotrexate or capecitabine, or pyrimethamine for infections.

These are the drug types documented to interact with the product's ingredients.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with strong clinical evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.

RepleteExtra may be worth considering if you're deficient in folate or looking to support mood and cognitive function, and none of your current medications are on the interaction list. If you take seizure medications, levodopa, thyroid hormones, antidepressants, sedatives, or cancer medications, this product is not appropriate for you without first checking with your doctor or pharmacist.

Talk with your own healthcare provider before starting to make sure it fits your health picture and doesn't interfere with anything you're already taking.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 3 of 3 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Aug 23, 2021.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about RepleteExtra, straight from the product label.

Brand CHK Nutrition
Net contents 120 Capsule(s)
Market status On market
Date entered into DSLD Aug 23, 2021
DSLD ID 252904
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for RepleteExtra by CHK Nutrition, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
4 Capsule(s)
Maximum serving Sizes:
4 Capsule(s)
Servings per container
30
IngredientAmount% DV
Folic Acid400 mcg--
L-Tyrosine1000 mg--
Folate680 mcg DFE170%
5-HTP300 mg--

Other ingredients: Vegetable Capsule, Rice Flour, Cellulose, Silicon Dioxide, Magnesium Stearate

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Suggested/Recommended/Usage/Directions

Directions: Take 4 capsules once or twice a day or as directed by your healthcare practitioner. Use only under medical supervision.

Use of CysReplete is recommended with this product to prevent sulfur amino acid depletion.

Precautions

If you are pregnant or nursing consult your health care practitioner before use.

Keep away from children

Brand IP Statement(s)

US Patents 6660777, 6384088, 6403657, 6548551, 6759437, 7268161, 7547723 with US and International PCT Patents Pending.

General Statements

This product is intended for resale.

Storage

Keep away from direct sunlight

FDA Disclaimer Statement

These statements have not been evaluated by the United States Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.

Formula

98% + Pure 5-HTP

FDA Statement of Identity

Dietary Supplement

Formulation

Does not contain wheat, corn, soy, sucrose, salt, starch, yeast, artificial flavors, artificial colorings, or other known allergens.

This product is manufactured in a cGMP certified facility.

GF Gluten-free

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

RepleteExtra by CHK Nutrition label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

RepleteExtra label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in RepleteExtra by CHK Nutrition

These are the 3 active ingredients this product is made of. Select any to open its full monograph.

Serving size4 Capsule(s) Dosage formCapsule Servings per container30 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

L-Tyrosine

Interacts with
21 drugs
1000 mg per serving

L-tyrosine is an amino acid your body uses to make brain chemicals like dopamine and norepinephrine. Some studies suggest it may help mental performan...

L-Tyrosine monograph & interactions

Folate

680 mcg DFE per serving Form: Folic Acid

5-HTP

Interacts with
398 drugs
300 mg per serving Form: Griffonia simplicifolia Seed Extract

5-HTP is a compound your body uses to make serotonin, and people take it as a supplement hoping to improve mood, sleep, and headaches. Some early rese...

5-HTP monograph & interactions

Other (inactive) ingredients: Vegetable Capsule, Rice Flour, Cellulose, Silicon Dioxide, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

RepleteExtra by CHK Nutrition Drug Interactions

Want to check YOUR meds against RepleteExtra?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
423Drugs
423 Moderate

Ingredients driving the most interactions

5-HTP 398
Folic Acid 40
L-Tyrosine 21

Individual Drug Interactions

The ingredients in RepleteExtra interact with 423 drugs. Click any drug to see the details.

3 of the 3 ingredients in RepleteExtra interact with drugs. Each result below shows which ingredient is responsible. 5-HTP Folic Acid L-Tyrosine

Each ingredient & the kinds of drugs it affects

For each ingredient in RepleteExtra with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

5-HTP3 drug types · 398 drugs

Carbidopa (Lodosyn)

Combining 5-HTP and carbidopa can increase the risk of serotonergic side effects.
Carbidopa is sometimes used with 5-HTP to minimize peripheral 5-HTP metabolism and boost the amount that reaches the brain. However, this combination might also increase the risk of some side effects including hypomania, restlessness, rapid speech, anxiety, insomnia, and aggressiveness. Combining carbidopa and 5-HTP might also increase the risk of scleroderma-like skin changes due to elevated serotonin levels.

Likelihood Possible Evidence D
Cns Depressants

Theoretically, concomitant use of 5-HTP with medications that cause sedation might have additive effects.
In clinical trials, 5-HTP has been associated with drowsiness and somnolence.

Likelihood Possible Evidence D
Serotonergic Drugs

Combining serotonergic drugs with 5-HTP might cause additive serotonergic effects.
5-HTP can increase serotonin levels and cause serotonergic effects. Theoretically, combining serotonergic drugs with 5-HTP might increase the risk of serotonergic side effects, including serotonin syndrome and cerebral vasoconstrictive disorders. However, serotonin syndrome with 5-HTP has not yet been reported in humans. Monitor patients for signs of serotonin syndrome and other serotonergic side effects if using 5-HTP with serotonergic drugs.

Likelihood Possible Evidence D
5-HTP full monograph & interactions

Folic Acid7 drug types · 40 drugs

5-Fluorouracil

Theoretically, high doses of folic acid might increase the toxicity of 5-fluorouracil.
Increases in gastrointestinal side effects of 5-fluorouracil, such as stomatitis and diarrhea, have been described in two clinical studies when leucovorin, a form of folic acid, was administered with 5-fluorouracil.

Likelihood Possible Evidence D
Capecitabine (Xeloda)

Use of high-dose folic acid might contribute to capecitabine toxicity.
Clinical research suggests that higher serum folate levels are associated with an increased risk for moderate or severe toxicity during capecitabine-based treatment for colorectal cancer. Additionally, in one case report, taking folic acid 15 mg daily might have contributed to increased toxicity, including severe diarrhea, vomiting, edema, hand-foot syndrome, and eventually death, in a patient prescribed capecitabine.

Likelihood Possible Evidence D
Methotrexate (Trexall, Others)

Folic acid might reduce the efficacy of methotrexate as a cancer treatment when given concurrently.
Methotrexate exerts its cytotoxic effects by preventing conversion of folic acid to the active form needed by cells. There is some evidence that folic acid supplements reduce the efficacy of methotrexate in the treatment of acute lymphoblastic leukemia, and theoretically they could reduce its efficacy in the treatment of other cancers. Advise cancer patients to consult their oncologist before using folic acid supplements. In patients treated with long-term, low-dose methotrexate for rheumatoid arthritis (RA) or psoriasis, folic acid supplements can reduce the incidence of side effects, without reducing efficacy.

Likelihood Probable Evidence B
Phenobarbital (Luminal)

Folic acid might have antagonistic effects on phenobarbital and increase the risk for seizures.
Folic acid can have direct convulsant activity in some people, reversing the effects of phenobarbital and worsening seizure control. Monitor closely for increased seizure activity.

Likelihood Probable Evidence B
Phenytoin (Dilantin)

Folic acid might reduce serum levels of phenytoin in some patients.
Folic acid may be a cofactor in phenytoin metabolism. Folic acid, in doses of 1 mg daily or more, can reduce serum levels of phenytoin in some patients. Increases in seizure frequency have been reported. If folic acid supplements are added to established phenytoin therapy, monitor serum phenytoin levels closely. If phenytoin and folic acid are started at the same time and continued together, adverse changes in phenytoin pharmacokinetics are avoided. Note that phenytoin also reduces serum folate levels.

Likelihood Probable Evidence B
Primidone (Mysoline)

Folic acid might have antagonistic effects on primidone and increase the risk for seizures.
Folic acid can have direct convulsant activity in some people, reversing the effects of primidone and worsening seizure control. Monitor closely for increased seizure activity. Note that primidone also reduces serum folate levels.

Likelihood Probable Evidence B
Pyrimethamine (Daraprim)

Folic acid might antagonize the effects of pyrimethamine.
Folic acid can antagonize the antiparasitic effects of pyrimethamine against toxoplasmosis and Pneumocystis carinii pneumonia. Folic acid doesn't antagonize the effects of pyrimethamine in the treatment of malaria, because malarial parasites cannot use exogenous folic acid. Use folinic acid as an alternative to folic acid when indicated.

Likelihood Probable Evidence D
Folic Acid full monograph & interactions

L-Tyrosine2 drug types · 21 drugs

Levodopa

Theoretically, tyrosine might decrease the effectiveness of levodopa.
Tyrosine and levodopa compete for absorption in the proximal duodenum by the large neutral amino acid (LNAA) transport system. Advise patients to separate doses of tyrosine and levodopa by at least 2 hours.

Likelihood Probable Evidence D
Thyroid Hormone

Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Tyrosine is a precursor to thyroxine and might increase levels of thyroid hormones.

Likelihood Probable Evidence D
L-Tyrosine full monograph & interactions
The maker

Brand information

Manufacturer and brand details for RepleteExtra, from the product label.

CHK Nutrition

See all CHK Nutrition products
Name
CHK Nutrition
Street Address
3930 E Calvary Rd
City
Duluth
State
MN
ZipCode
55803
Phone Number
1-877-538-8388
Web Address
www.CHKnutrition.com
Pharmacist Counseling Corner

RepleteExtra by CHK Nutrition: Common Questions

Does RepleteExtra by CHK Nutrition interact with any medications?
Yes. Based on its ingredients, RepleteExtra has a known interaction with 423 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
RepleteExtra contains 3 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Is RepleteExtra safe to take during pregnancy?
Folic acid is recommended during pregnancy at standard prenatal doses to help prevent birth defects. However, late-pregnancy use has been associated with increased childhood asthma risk in population studies. L-tyrosine and 5-HTP lack sufficient safety data in pregnancy, so avoid them unless a doctor advises otherwise. Talk with your obstetrician or pharmacist before starting to make sure it's right for your situation.
Can I take RepleteExtra while breastfeeding?
Folic acid is considered safe at normal recommended doses while breastfeeding. L-tyrosine and 5-HTP have not enough safety information, so caution is advised while breastfeeding. Check with your doctor or pharmacist before taking it.
What are the most common side effects of RepleteExtra?
At standard doses, folic acid is generally well tolerated. At higher doses (5 mg daily or more), you might experience abdominal cramps, diarrhea, or rash. L-tyrosine commonly causes fatigue, headache, heartburn, and nausea. 5-HTP often causes nausea, diarrhea, headache, drowsiness, and fatigue, especially when you first start taking it.
Does RepleteExtra actually help with depression?
Both folic acid and 5-HTP are rated possibly effective for depression based on the evidence we hold, meaning some research supports their use but the data isn't conclusive. Results vary from person to person, and neither is a substitute for professional mental health care. Talk with your doctor about whether this product makes sense for you.
What is 5-HTP and why is it in this product?
5-HTP is a compound your body naturally makes from the amino acid tryptophan; it's a precursor to serotonin, a neurotransmitter involved in mood and sleep. It's included in RepleteExtra because it's possibly effective for depression and may support cognitive function, though the evidence isn't strong.
Can RepleteExtra interact with my blood pressure or heart medications?
The interactions we have documented for RepleteExtra don't include a specific interaction with blood pressure or heart medications in our data. However, to be certain, check your exact medications with the search tool on this page or talk with your pharmacist before starting.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if RepleteExtra is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

RepleteExtra label
Go deeper

The Full Monographs Behind RepleteExtra’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Tyrosine

Interacts with 21 drugs

L-tyrosine is an amino acid your body uses to make brain chemicals like dopamine and norepinephrine. Some studies suggest it may help mental performance during short-term stress, sleep loss,...

Read the full Tyrosine monograph → Herb & supplement monograph

Folic Acid

Interacts with 40 drugs

Folic acid is the man-made form of vitamin B9 and is one of the most well-studied supplements, especially for preventing serious birth defects when taken before and during early pregnancy. I...

Read the full Folic Acid monograph → Herb & supplement monograph

5-htp

Interacts with 398 drugs

5-HTP is a compound your body uses to make serotonin, and people take it as a supplement hoping to improve mood, sleep, and headaches. Some early research is promising, but the overall evide...

Read the full 5-htp monograph →
Sources

Sources & How We Checked

RepleteExtra's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

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

The 92 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Folic Acid 56 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Duhra P. Treatment of gastrointestinal symptoms associated with methotrexate therapy for psoriasis. J Am Acad Dermatol 1993;28:466-9. PubMed
  3. Morgan SL, Baggott JE, Vaughn WH, et al. Supplementation with folic acid during methotrexate therapy for rheumatoid arthritis. A double-blind, placebo-controlled trial. Ann Intern Med 1994;121:833-41. PubMed
  4. Froscher W, Maier V, Laage M, et al. Folate deficiency, anticonvulsant drugs, and psychiatric morbidity. Clin Neuropharmacol 1995;18:165-82. PubMed
  5. Lewis DP, Van Dyke DC, Willhite LA, et al. Phenytoin-folic acid interaction. Ann Pharmacother 1995;29:726-35. PubMed
  6. Berg MJ, Stumbo PJ, Chenard CA, et al. Folic acid improves phenytoin pharmacokinetics. J Am Diet Assoc 1995;95:352-6. PubMed
  7. Berg MJ, Fincham RW, Ebert BE, et al. Phenytoin pharmacokinetics: Before and after folic acid administration. Epilepsia 1992;33:712-20. PubMed
  8. Shafer RB, Nuttall FQ. Calcium and folic acid absorption in patients taking anticonvulsant drugs. J Clin Endocrinol Metab 1975;41:1125-9. PubMed
  9. Leeb BF, Witzmann G, Ogris E, et al. Folic acid and cyanocobalamin levels in serum and erythrocytes during low-dose methotrexate therapy of rheumatoid arthritis and psoriatic arthritis patients. Clin Exp Rheumatol 1995;13:459-63.
  10. Morgan SL, Baggott JE, Lee JY, Alarcón GS. Folic acid supplementation prevents deficient blood folate levels and hyperhomocysteinemia during longterm, low dose methotrexate therapy for rheumatoid arthritis: implications for cardiovascular disease preventi
  11. Dijkmans BA. Folate supplementation and methotrexate. Br J Rheumatol 1995;34:1172-4. PubMed
  12. Segal S, Kaminski S. Drug-nutrient interactions. American Druggist 1996 Jul;42-8.
  13. Lambie DG, Johnson RH. Drugs and folate metabolism. Drugs 1985;30:145-55. PubMed
  14. Amer College of Rheumatology ad hoc committee on clinical guidelines. Guidelines for monitoring drug therapy in rheumatoid arthritis. Arthritis Rheum 1996;39:723-31. DOI
  15. Suitor CW, Bailey LB. Dietary folate equivalents: interpretation and application. J Am Diet Assoc 2000;100:88-94. PubMed
  16. 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
  17. Sandoval M, Charbonnet RM, Okuhama NN, et al. Cat's claw inhibits TNFalpha production and scavenges free radicals: role in cytoprotection. Free Radic Biol Med 2000;29:71-78.
  18. Antony AC. Megaloblastic Anemias. In: Hoffman R, Benz Jr EJ, Shattil SJ, et al. Hematology: Basic Principles and Practice. 3rd ed. New York, NY: Churchill Livingstone 2000: 451-79.
  19. Reynolds EH. Neurological aspects of folate and vitamin B12 metabolism. Clin Haematol 1976;5:661-96. DOI
  20. Reynolds EH. Folate metabolism and anticonvulsant therapy. Proc R Soc Med 1974;67:68.
  21. Ortiz Z, Shea B, Suarez Almazor M, et al. Folic acid and folinic acid for reducing side effects in patients receiving methotrexate for rheumatoid arthritis (Cochrane Review). Cochrane Database Syst Rev 2000;2:CD000951. PubMed
  22. Van Delden C, Hirschel B. Folinic acid supplements to pyrimethamine-sulfadiazine for Toxoplasma encephalitis are associated with better outcome (letter). J Infect Dis 1996;173:1294-5. PubMed
  23. Schroder H, Clausen N, Ostergard E, Pressler T. Folic acid supplements in vitamin tablets: a determinant of hematological drug tolerance in maintenance therapy of childhood acute lymphoblastic leukemia. Ped Hematol Oncol 1986;3:241-7. PubMed
  24. Lange H, Suryapranata H, De Luca G, et al. Folate therapy and in-stent restenosis after coronary stenting. N Engl J Med 2004;350:2673-81. PubMed
  25. Morris MC, Evans DA, Bienias JL, et al. Dietary folate and vitamin B12 intake and cognitive decline among community-dwelling older persons. Arch Neurol 2005;62:641-5. PubMed
  26. Bonaa KH, Njolstad I, Ueland PM, et al. NORVIT: Homocysteine lowering and cardiovascular events after acute myocardial infarction. N Enlg J Med 2006;354:1578-88. PubMed
  27. Lawson KA, Wright ME, Subar A, et al. Multivitamin use and risk of prostate cancer in the National Institutes of Health-AARP Diet and Health Study. J Natl Cancer Inst 2007;99:754-64. PubMed
  28. Figueiredo JC, Grau MV, Haile RW, et al. Folic acid and risk of prostate cancer: Results from a randomized clinical trial. J Natl Cancer Inst 2009;101:432-5. PubMed
  29. Clippe C, Freyer G, Milano G, Trillet-Lenoir V. Lethal toxicity of capecitabine due to abusive folic acid prescription. Clin Oncol (R Coll Radiol) 2003;15:299-300. PubMed
  30. Bedford Laboratories. Leucovorin calcium [package insert]. Bedford, OH. September 2008. Available at: http://www.bedfordlabs.com/BedfordLabsWeb/products/inserts/LCV-P02.pdf.
  31. Ebbing M, Bonaa KH, Nygard O, et al. Cancer incidence and mortality after treatment with folic acid and vitamin B12. JAMA 2009;302:2119-26.
  32. Haberg, S. E., London, S. J., Stigum, H., Nafstad, P., and Nystad, W. Folic acid supplements in pregnancy and early childhood respiratory health. Arch Dis.Child 2009;94(3):180-184. PubMed
  33. Whitrow, M. J., Moore, V. M., Rumbold, A. R., and Davies, M. J. Effect of supplemental folic acid in pregnancy on childhood asthma: a prospective birth cohort study. Am J Epidemiol. 12-15-2009;170(12):1486-1493. PubMed
  34. Collin, S. M., Metcalfe, C., Refsum, H., Lewis, S. J., Zuccolo, L., Smith, G. D., Chen, L., Harris, R., Davis, M., Marsden, G., Johnston, C., Lane, J. A., Ebbing, M., Bonaa, K. H., Nygard, O., Ueland, P. M., Grau, M. V., Baron, J. A., Donovan, J. L., Nea
  35. Baggott, J. E., Oster, R. A., and Tamura, T. Meta-analysis of cancer risk in folic acid supplementation trials. Cancer Epidemiol. 2012;36(1):78-81. PubMed
  36. Fonseca VA, Lavery LA, Thethi TK, et al. Metanx in type 2 diabetes with peripheral neuropathy: A randomized trial. Am J Med 2013;126(2):141-9. PubMed
  37. Hankey GJ, Eikelboom JW, Yi Q, et al. Treatment with B vitamins and incidence of cancer in patients with previous stroke or transient ischemic attack: Results of a randomized placebo-controlled trial. Stroke 2012;43(6):1572-7. PubMed
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  39. van Wijngaarden JP, Swart KM, Enneman AW, et al. Effect of daily vitamin B-12 and folic acid supplementation on fracture incidence in elderly individuals with an elevated plasma homocysteine concentration: B-PROOF, a randomized controlled trial. Am J Clin
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