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

Elder-C Ingredients & Drug Interactions

by North American Herb & Spice

Elder-C label
See full label image
Powder Category: Botanical With Nutrients
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 Elder-C 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

Elder-C is a dietary supplement by North American Herb & Spice with 3 active ingredients. Its ingredients are commonly taken for common cold and immune support, antioxidant support, skin health and collagen formation.Based on those ingredients, 326 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Vitamin C, Elderberry powder. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Elder-C by North American Herb & Spice

Ask about any prescription or over-the-counter medication and we check it for interactions with Elder-C by North American Herb & Spice — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Elder-C by North American Herb & Spice

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 Jul 23, 2026

What’s inside

Low disclosure
Ingredient Transparency · database check
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 1 of its 3 active ingredients.

Elder-C contains three active ingredients: vitamin C, elderberry powder, and wild Amazon Camu Camu berry powder. Vitamin C supports immune function and acts as an antioxidant.

Elderberry is traditionally used for respiratory and immune support. Camu Camu berry is included for additional vitamin C content and antioxidant benefits.

There are no inactive ingredients listed for this product.

Does it work?

Moderate 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
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: support healthy immune and respiratory response.
  • We looked for evidence on: Acute bronchitis, Chronic obstructive pulmonary disease (COPD), Exercise-induced respiratory infections, Lower respiratory tract infections, Common cold, Influenza — and 1 related terms.
  • The strongest evidence on file: Vitamin C is rated "Possibly Effective" for Exercise-induced respiratory infections (Natural Medicines).
  • Also on file: Vitamin C is rated "Possibly Ineffective" for Acute bronchitis.
  • Also on file: Elderberry is rated "Insufficient Reliable Evidence To Rate" for Chronic obstructive pulmonary disease (COPD), Respiratory tract infections, Lower respiratory tract infections.

Vitamin C is effective for preventing and treating vitamin C deficiency and is possibly effective for anemia of chronic disease, atrial fibrillation, cataracts, and exercise-induced respiratory infections. For elderberry, the evidence we hold does not establish effectiveness for hay fever, heart disease, chronic fatigue, COPD, brain function, or respiratory infections.

For Camu Camu berry, effectiveness data is not established in the information we have.

The evidence, ingredient by ingredient Vitamin C Elderberry Camu Camu

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 2 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.

Vitamin C is generally well tolerated at normal dietary and supplement doses. However, very high doses can cause abdominal cramps, heartburn, osmotic diarrhea, nausea, vomiting, and headache—especially above 2 grams daily.

Kidney stones have been reported in people prone to them. Properly cooked elderberry products are generally well tolerated; raw or unripe berries, seeds, leaves, and bark can be toxic due to cyanogenic glycosides and may cause nausea, vomiting, severe diarrhea, weakness, dizziness, numbness, and stupor.

Regarding pregnancy and lactation: normal amounts of vitamin C from food and prenatal vitamins are fine, but avoid high-dose supplements unless your doctor advises otherwise. Elderberry should be avoided during pregnancy and breastfeeding due to insufficient safety information.

Camu Camu berry in supplement form should be avoided during pregnancy and breastfeeding as well.

Side effects, ingredient by ingredient Vitamin C Elderberry Camu Camu

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?
  • 2 of the 3 matched ingredients can interact with medications — Elderberry, Vitamin C.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; cancer treatments.
  • For scale: 326 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 Elder-C, double-check with your doctor or pharmacist if you take any of these: estrogen-based birth control or hormone replacement therapy; warfarin or other blood thinners; levothyroxine or other thyroid medications; alkylating agent or antitumor antibiotic chemotherapy drugs; immunosuppressants; pazopanib; fluphenazine; or indinavir. All of these have documented Moderate interactions with ingredients in this product.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with some supporting evidence for its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

This product may be right for you if you're looking for vitamin C and immune support, but it carries interaction risks with estrogen-based birth control, blood thinners, thyroid medication, cancer drugs, and immunosuppressants. If you take any prescription medications—especially blood thinners, hormone therapy, chemotherapy, or drugs for transplant or autoimmune disease—check your exact medications with your doctor or pharmacist before starting Elder-C.

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 Jun 16, 2022.

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 Elder-C, straight from the product label.

Brand North American Herb & Spice
Barcode (UPC) 635824007029
Net contents 3 Ounce(s); 85 Gram(s)
Market status On market
Date entered into DSLD Jun 16, 2022
DSLD ID 269334
Product type Botanical With Nutrients
Supplement form Powder
Dietary claims / uses Nutrient, 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 Elder-C by North American Herb & Spice, 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:
2 Gram(s)
Maximum serving Sizes:
2 Gram(s)
Servings per container
42
UPC/BARCODE
635824007029
IngredientAmount% DV
Vitamin C110 mgs150%
Elderberry powder0 NP--
wild Amazon Camu Camu berry powder0 NP--

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 one teaspoon or add to water, juices, smoothies, or favorite recipes. One heaping teaspoonful is equivalent to about 1/4 cup of berries.

Use daily to support a healthy immune system.

Formulation

Feel the power of real, unaltered berries—the power of trapped sunlight.

Healthy immune support

Non-GMO Gluten-free No additives No added sugar Nothing artificial

Formula

Elder-C is the potency of air-dried elderberries plus wild, raw camu camu powder. Each serving of Elder-C contains over 110 mgs of vitamin C, 150% of the RDI. Elder-C is ideal for supporting a healthy immune and respiratory response. These elderberries are a top source of flavonoids and anthocyanins in their most potent form.

Elderberry anthocyanins plus wild vitamin C

FDA Statement of Identity

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Dietary Supplement

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

See for yourself

Elder-C by North American Herb & Spice label

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

Elder-C 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 Elder-C by North American Herb & Spice

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

Serving size2 Gram(s) Dosage formPowder Servings per container42 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.

Vitamin C

Interacts with
207 drugs
110 mgs per serving

Vitamin C (ascorbic acid) is an essential nutrient your body needs but cannot make, so you must get it from food or supplements. It's important for im...

Vitamin C monograph & interactions

Elderberry powder

Interacts with
121 drugs
0 NP per serving

Elderberry is a popular herbal supplement, mainly taken to help with colds and flu. Some small studies suggest it may modestly shorten cold or flu sym...

Elderberry powder monograph & interactions

Wild Amazon Camu Camu berry powder

No known
interactions
0 NP per serving

Camu camu is an Amazonian berry that is very high in vitamin C and plant antioxidants, which is why it is popular as an immune and antioxidant supplem...

Wild Amazon Camu Camu berry powder monograph & interactions
Interaction report

Elder-C by North American Herb & Spice Drug Interactions

Want to check YOUR meds against Elder-C?

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
326Drugs
220 Moderate 106 Minor

Ingredients driving the most interactions

Vitamin C 207
Elderberry powder 121

Individual Drug Interactions

The ingredients in Elder-C interact with 326 drugs. Click any drug to see the details.

2 of the 3 ingredients in Elder-C interact with drugs. Each result below shows which ingredient is responsible. Vitamin C Elderberry powder

Each ingredient & the kinds of drugs it affects

For each ingredient in Elder-C 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.

Vitamin C13 drug types · 207 drugs

Alkylating Agents

Theoretically, antioxidant effects of vitamin C might reduce the effectiveness of alkylating agents.
The use of antioxidants like vitamin C during chemotherapy is controversial. There is concern that antioxidants could reduce the activity of chemotherapy drugs that generate free radicals, such as cyclophosphamide, chlorambucil, carmustine, busulfan, and thiotepa. In contrast, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that could interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effect, if any, antioxidants such as vitamin C have on chemotherapy.

Likelihood Possible Evidence D
Aluminum

Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.
Research in animals and humans shows that vitamin C increases aluminum absorption, theoretically by chelating aluminum and keeping it in solution where it is available for absorption. In people with normal renal function, urinary excretion of aluminum will likely increase, making aluminum retention and toxicity unlikely. Patients with renal failure who take aluminum-containing compounds such as phosphate binders should avoid vitamin C supplements in doses above the recommended dietary allowances.

Likelihood Probable Evidence B
Antitumor Antibiotics

Theoretically, the antioxidant effects of vitamin C might reduce the effectiveness of antitumor antibiotics.
The use of antioxidants like vitamin C during chemotherapy is controversial. There is concern that antioxidants could reduce the activity of chemotherapy drugs which generate free radicals, such as doxorubicin. In contrast, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that could interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effects, if any, antioxidants such as vitamin C have on chemotherapy.

Likelihood Possible Evidence D
Estrogens

Vitamin C might increase blood levels of estrogens.
Increases in plasma estrogen levels of up to 55% occur under some circumstances when vitamin C is taken concurrently with oral contraceptives or hormone replacement therapy, including topical products. It is suggested that vitamin C prevents oxidation of estrogen in the tissues, regenerates oxidized estrogen, and reduces sulfate conjugation of estrogen in the gut wall. When tissue levels of vitamin C are high, these processes are already maximized and supplemental vitamin C does not have any effect on estrogen levels. Increases in plasma estrogen levels may occur when patients who are deficient in vitamin C take supplements. Monitor these patients for estrogen-related side effects.

Likelihood Probable Evidence B
Fluphenazine (Prolixin)

Theoretically, vitamin C might decrease levels of fluphenazine.
In one patient there was a clinically significant decrease in fluphenazine levels when vitamin C (500 mg twice daily) was started. The mechanism is not known, and there is no further data to confirm this interaction.

Likelihood Possible Evidence D
Indinavir (Crixivan)

Vitamin C can modestly reduce indinavir levels.
One pharmacokinetic study shows that taking vitamin C 1 gram orally once daily along with indinavir 800 mg orally three times daily reduces the area under the concentration-time curve of indinavir by 14%. The mechanism of this interaction is unknown, but it is unlikely to be clinically significant in most patients. The effect of higher doses of vitamin C on indinavir levels is unknown.

Likelihood Probable Evidence B
Levothyroxine (Synthroid, Others)

Vitamin C can increase levothyroxine absorption.
Two clinical studies in adults with poorly controlled hypothyroidism show that swallowing levothyroxine with a glass of water containing vitamin C 500-1000 mg in solution reduces thyroid stimulating hormone (TSH) levels and increases thyroxine (T4) levels when compared with taking levothyroxine alone. This suggests that vitamin C increases the oral absorption of levothyroxine, possibly due to a reduction in pH.

Likelihood Probable Evidence B
Warfarin (Coumadin)

High-dose vitamin C might reduce the levels and effectiveness of warfarin.
Vitamin C in high doses may cause diarrhea and possibly reduce warfarin absorption. There are reports of two people who took up to 16 grams daily of vitamin C and had a reduction in prothrombin time. Lower doses of 5-10 grams daily can also reduce warfarin absorption. In many cases, this does not seem to be clinically significant. However, a case of warfarin resistance has been reported for a patient who took vitamin C 500 mg twice daily. Cessation of vitamin C supplementation resulted in a rapid increase in international normalized ratio (INR). Tell patients taking warfarin to avoid taking vitamin C in excessively high doses (greater than 10 grams daily). Lower doses may be safe, but the anticoagulation activity of warfarin should be monitored. Patients who are stabilized on warfarin while taking vitamin C should avoid adjusting vitamin C dosage to prevent the possibility of warfarin resistance.

Likelihood Possible Evidence D
Acetaminophen (Tylenol, Others)

High-dose vitamin C might slightly prolong the clearance of acetaminophen.
A small pharmacokinetic study in healthy volunteers shows that taking high-dose vitamin C (3 grams) 1.5 hours after taking acetaminophen 1 gram slightly increases the apparent half-life of acetaminophen from around 2.3 hours to 3.1 hours. Ascorbic acid competitively inhibits sulfate conjugation of acetaminophen. However, to compensate, elimination of acetaminophen glucuronide and unconjugated acetaminophen increases. This effect is not likely to be clinically significant.

Likelihood Probable Evidence B
Aspirin

Acidification of the urine by vitamin C might increase aspirin levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams daily of vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction is not clinically significant.

Likelihood Possible Evidence B
Choline Magnesium Trisalicylate (Trilisate)

Acidification of the urine by vitamin C might increase choline magnesium trisalicylate levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams daily of vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction probably is not clinically significant.

Likelihood Possible Evidence B
Niacin

Vitamin C might decrease the beneficial effects of niacin on high-density lipoprotein (HDL) cholesterol levels.
A combination of niacin and simvastatin (Zocor) effectively raises HDL cholesterol levels in patients with coronary disease and low HDL levels. Clinical research shows that taking a combination of antioxidants (vitamin C, vitamin E, beta-carotene, and selenium) along with niacin and simvastatin (Zocor) attenuates this rise in HDL, specifically the HDL-2 and apolipoprotein A1 fractions, by more than 50% in patients with coronary disease. It is not known whether this adverse effect is due to a single antioxidant such as vitamin C, or to the combination. It also is not known whether it will occur in other patient populations.

Likelihood Possible Evidence A
Salsalate (Disalcid)

Acidification of the urine by vitamin C might increase salsalate levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams/day vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction probably is not clinically significant.

Likelihood Possible Evidence B
Vitamin C full monograph & interactions

Elderberry powder2 drug types · 121 drugs

Immunosuppressants

Theoretically, elderberry might interfere with immunosuppressant therapy due to its immunostimulant activity.
Elderberry has immunostimulant activity, increasing the production of cytokines, including interleukin and tumor necrosis factor.

Likelihood Possible Evidence B
Pazopanib (Votrient)

Theoretically, elderberry might interact with pazopanib, potentially increasing the risk of adverse effects.
In one case, a 65-year-old patient taking pazopanib for 4 weeks for soft-tissue sarcoma developed severe nausea, loose stools, and elevated alanine transaminase and aspartate transaminase levels and was diagnosed with grade 3 liver injury. The patient reported taking elderberry supplements for 2 years, dose unspecified, and was also taking a multivitamin and a calcium supplement. The patient's symptoms and liver enzyme levels improved upon discontinuation of pazopanib and all supplements. Pazopanib treatment was re-initiated, at a lower dose, with no further evidence of liver injury. It was unclear in this case report if the elderberry supplements were derived from the berry, the flower, or the combination.

Likelihood Possible Evidence D
Elderberry powder full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Elder-C, from the product label.

North American Herb & Spice

See all North American Herb & Spice products
Name
North American Herb & Spice
Street Address
13900 W. Polo Trail Drive
City
Lake Forest
State
IL
ZipCode
60045
Phone Number
1-800-243-5242
Web Address
www.oreganol.com
Pharmacist Counseling Corner

Elder-C by North American Herb & Spice: Common Questions

Does Elder-C by North American Herb & Spice interact with any medications?
Yes. Based on its ingredients, Elder-C has a known interaction with 326 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Elder-C 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.
Can I take Elder-C if I'm on birth control?
Vitamin C in this product might increase estrogen blood levels by up to 55%, which could affect how your birth control works. Talk with your doctor or pharmacist before adding Elder-C to your routine if you're on oral contraceptives or any hormone-based birth control.
Is Elder-C safe during pregnancy?
Normal amounts of vitamin C from food and prenatal vitamins are fine, but avoid high-dose supplements unless your doctor advises it. Elderberry should be avoided during pregnancy due to insufficient safety data. Talk with your doctor or pharmacist before taking this product if you're pregnant or planning to become pregnant.
Can I take Elder-C while breastfeeding?
Normal dietary amounts of vitamin C are considered safe while breastfeeding; avoid high-dose supplements unless your healthcare provider directs otherwise. Elderberry and Camu Camu berry in supplement form should be avoided while breastfeeding due to lack of safety information. Check with your doctor or pharmacist for personalized advice.
What are the side effects of Elder-C?
Vitamin C at normal doses is well tolerated. Very high doses (above 2 grams daily) may cause abdominal cramps, heartburn, diarrhea, nausea, vomiting, or headache, and kidney stones in people prone to them. Properly cooked elderberry is generally well tolerated; side effects from this product are unlikely at normal doses.
Can I take Elder-C with my blood thinner?
High-dose vitamin C can reduce warfarin (Coumadin) absorption and effectiveness. If you take warfarin or another blood thinner, talk with your doctor or pharmacist before starting Elder-C to make sure it's safe for you.
Does Elder-C work for colds and flu?
Vitamin C is possibly effective for exercise-induced respiratory infections, but evidence we hold does not establish that elderberry works for respiratory tract infections, hay fever, or similar conditions. Your doctor or pharmacist can discuss whether this product fits your health goals.

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

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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.

Elder-C label
Go deeper

The Full Monographs Behind Elder-C’s Ingredients

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

Herb & supplement monograph

Vitamin C

Interacts with 207 drugs

Vitamin C (ascorbic acid) is an essential nutrient your body needs but cannot make, so you must get it from food or supplements. It's important for immune function, collagen, and acts as an...

Read the full Vitamin C monograph → Herb & supplement monograph

Elderberry

Interacts with 121 drugs

Elderberry is a popular herbal supplement, mainly taken to help with colds and flu. Some small studies suggest it may modestly shorten cold or flu symptoms, but the evidence is limited and n...

Read the full Elderberry monograph → Herb & supplement monograph

Camu Camu

Camu camu is an Amazonian berry that is very high in vitamin C and plant antioxidants, which is why it is popular as an immune and antioxidant supplement. Human research is still limited, so...

Read the full Camu Camu monograph →
Sources

Sources & How We Checked

Elder-C'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 59 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.

Vitamin C 51 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Back DJ, Breckenridge AM, MacIver M, et al. Interaction of ethinyloestradiol with ascorbic acid in man. Br Med J (Clin Res Ed) 1981;282:1516.
  3. Morris JC, Beeley L, Ballantine N. Interaction of ethinyloestradiol with ascorbic acid in man [letter]. Br Med J (Clin Res Ed) 1981;283:503.
  4. Labriola D, Livingston R. Possible interactions between dietary antioxidants and chemotherapy. Oncology 1999;13:1003-8.
  5. Dwyer JH, Merz NB, Shirocre AM, et al. Progression of early atherosclerosis and intake of vitamin C and vitamin E from supplements and food. The Los Angeles Atherosclerosis Study. 41st Annual Conference on Cardiovascular Disease Epidemiology and Prevent
  6. Levine M, Rumsey SC, Daruwala R, et al. Criteria and recommendations for vitamin C intake. JAMA 1999;281:1415-23. PubMed
  7. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  8. Segal S, Kaminski S. Drug-nutrient interactions. American Druggist 1996 Jul;42-8.
  9. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: National Academy Press, 2000. Available at: http://www.nap.edu/books/0309069351/html/.
  10. Houston JB, Levy G. Drug biotransformation interactions in man VI: Acetaminophen and ascorbic acid. J Pharm Sci 1976;65:1218-21. PubMed
  11. Brown BG, Zhao XQ, Chait A, et al. Simvastatin and niacin, antioxidant vitamins, or the combination for the prevention of coronary disease. N Engl J Med 2001;345:1583-93. DOI
  12. Rosenthal G. Interaction of ascorbic acid and warfarin. JAMA 1971;215:1671. DOI
  13. Hume R, Johnstone JM, Weyers E. Interaction of ascorbic acid and warfarin. JAMA 1972;219:1479. DOI
  14. Smith EC, Skalski RJ, Johnson GC, Rossi GV. Interaction of ascorbic acid and warfarin. JAMA 1972;221:1166. DOI
  15. Traxer O, Huet B, Poindexter J, et al. Effect of ascorbic acid consumption on urinary stone risk factors. J Urol 2003;170:397-401.. PubMed
  16. Domingo JL, Gomez M, Llobet JM, Richart C. Effect of ascorbic acid on gastrointestinal aluminum absorption (letter). Lancet 1991;338:1467.
  17. Domingo JL, Gomez M, Llobet JM, Corbella J. Influence of some dietary constituents on aluminum absorption and retention in rats. Kidney Int 1991;39:598-601. PubMed
  18. Partridge NA, Regnier FE, White JL, Hem SL. Influence of dietary constituents on intestinal absorption of aluminum. Kidney Int 1989;35:1413-7. PubMed
  19. Mc Leod DC, Nahata MC. Inefficacy of ascorbic acid as a urinary acidifier (letter). N Engl J Med 1977;296:1413. DOI
  20. Hansten PD, Hayton WL. Effect of antacid and ascorbic acid on serum salicylate concentration. J Clin Pharmacol 1980;20:326-31. PubMed
  21. Dysken MW, Cumming RJ, Channon RA, Davis JM. Drug interaction between ascorbic acid and fluphenazine. JAMA 1979;241:2008. DOI
  22. Vihtamaki T, Parantainen J, Koivisto AM, et al. Oral ascorbic acid increases plasma oestradiol during postmenopausal hormone replacement therapy. Maturitas 2002;42:129-35. PubMed
  23. Slain D, Amsden JR, Khakoo RA, et al. Effect of high-dose vitamin C on the steady-state pharmacokinetics of the protease inhibitor indinavir in healthy volunteers. Pharmacotherapy 2005;25:165-70. PubMed
  24. Cheung MC, Zhao XQ, Chait A, et al. Antioxidant supplements block the response of HDL to simvastatin-niacin therapy in patients with coronary artery disease and low HDL. Arterioscler Thromb Vasc Biol 2001;21:1320-6. PubMed
  25. Feetam CL, Leach RH, Meynell MJ. Lack of a clinically important interaction between warfarin and ascorbic acid. Toxicol Appl Pharmacol 1975;31:544-7. PubMed
  26. Weintraub M, Griner PF. Warfarin and ascorbic acid: lack of evidence for a drug interaction. Toxicol Appl Pharmacol 1974;28:53-6. PubMed
  27. Lee DH, Folsom AR, Harnack L, et al. Does supplemental vitamin C increase cardiovascular disease risk in women with diabetes? Am J Clin Nutr 2004;80:1194-200. PubMed
  28. Taylor EN, Stampfer MJ, Curhan GC. Dietary factors and the risk of incident kidney stones in men: new insights after 14 years of follow-up. J Am Soc Nephrol 2004;15:3225-32. PubMed
  29. Ward NC, Hodgson JM, Croft KD, et al. The combination of vitamin C and grape-seed polyphenols increases blood pressure: a randomized, double-blind, placebo-controlled trial. J Hypertens 2005;23:427-34.. PubMed
  30. Prasad KN. Rationale for using high-dose multiple dietary antioxidants as an adjunct to radiation therapy and chemotherapy. J Nutr 2004;134:3182S-3S. PubMed
  31. Conklin KA. Cancer chemotherapy and antioxidants. J Nutr 2004;134:3201S-3204S. PubMed
  32. Fairweather-Tait S, Hickson K, McGaw B, et al. Orange juice enhances aluminium absorption from antacid preparation. Eur J Clin Nutr. 1994;48(1):71-3.
  33. Gruenwald, J., Graubaum, H. J., Busch, R., and Bentley, C. Safety and tolerance of ester-C compared with regular ascorbic acid. Adv.Ther. 2006;23(1):171-178.
  34. Rahimi, R., Nikfar, S., Rezaie, A., and Abdollahi, M. A meta-analysis on the efficacy and safety of combined vitamin C and E supplementation in preeclamptic women. Hypertens.Pregnancy. 2009;28(4):417-434. PubMed
  35. Einerson, B., Nathorn, C., Kitiyakara, C., Sirada, M., and Thamlikitkul, V. The efficacy of ascorbic acid in suboptimal responsive anemic hemodialysis patients receiving erythropoietin: a meta-analysis. J Med.Assoc.Thai. 2011;94 Suppl 1:S134-S146.
  36. Li, G., Li, L., Yu, C., and Chen, L. Effect of vitamins C and E supplementation on Helicobacter pylori eradication: a meta-analysis. Br.J Nutr 2011;106(11):1632-1637.
  37. Chen X, Shen L, Gu X, et al. High-dose supplementation with vitamin C--induced pediatric urolithiasis: the first case report in a child and literature review. Urology. 2014;84(4):922-4. PubMed
  38. Sattar A, Willman JE, Kolluri R. Possible warfarin resistance due to interaction with ascorbic acid: case report and literature review. Am J Health Syst Pharm. 2013;70(9):782-6. PubMed
  39. Yaich S, Chaabouni Y, Charfeddine K, et al. Secondary oxalosis due to excess vitamin C intake: a cause of graft loss in a renal transplant recipient. Saudi J Kidney Dis Transpl. 2014;25(1):113-6. PubMed
  40. Jalloh MA, Gregory PJ, Hein D, et al. Dietary supplement interactions with antiretrovirals: a systematic review. Int J STD AIDS. 2017 Jan;28(1):4-15. PubMed
  41. Rumbold A, Ota E, Nagata C, Shahrook S, Crowther CA. Vitamin C supplementation in pregnancy. Cochrane Database Syst Rev. 2015;(9):CD004072. PubMed
  42. Seo MS, Kim JK, Shim JY. High-dose vitamin C promotes regression of multiple pulmonary metastases originating from hepatocellular carcinoma. Yonsei Med J. 2015;56(5):1449-52. PubMed
  43. Skelin M, Lucijanic T, Amidzic Klaric D, et al. Factors Affecting Gastrointestinal Absorption of Levothyroxine: A Review. Clin Ther. 2017 Feb;39(2):378-403. PubMed
  44. Jiang K, Tang K, Liu H, Xu H, Ye Z, Chen Z. Ascorbic acid supplements and kidney stones incidence among men and women: a systematic review and meta-analysis. Urol J. 2019;16(2):115-120.
  45. Thomas S, Patel D, Bittel B, et al. Effect of High-Dose Zinc and Ascorbic Acid Supplementation vs Usual Care on Symptom Length and Reduction Among Ambulatory Patients With SARS-CoV-2 Infection: The COVID A to Z Randomized Clinical Trial. JAMA Netw Open. 2 PubMed
  46. Giffen MA, McLemore JL. Hyperoxalosis Secondary to Intravenous Vitamin C Administration as a Non-Allopathic Treatment for Cancer. Acad Forensic Pathol 2019;9(1-2):118-126. PubMed
  47. Maike A, Sturgill D, Gallan A. Oxalate Nephropathy in a Renal Transplant Recipient After Receiving High Dose Ascorbic Acid. Am J Med Sci 2021. PubMed
  48. Shen ZY, Chen YR, Wang MC, Chang SS. High-dose vitamin C-induced acute oxalate nephropathy in a renal transplant recipient: a case report and literature review. Asian J Surg 2022. PubMed
  49. Yanase F, Spano S, Maeda A, et al. Mega-dose sodium ascorbate: a pilot, single-dose, physiological effect, double-blind, randomized, controlled trial. Crit Care 2023;27(1):371. PubMed
  50. Sharma Y, Sumanadasa S, Shahi R, et al. Efficacy and safety of vitamin C supplementation in the treatment of community-acquired pneumonia: a systematic review and meta-analysis with trial sequential analysis. Sci Rep 2024;14(1):11846. PubMed
  51. Pejcic AV, Petrovic NZ, Djordjic MD, Milosavljevic MN. Vitamin C Levels in Pregnant Women and the Efficacy of Vitamin C Supplements in Preventing Premature Rupture of Membranes: A Systematic Review and Meta-Analysis. Balkan Med J 2024;41(4):248-260. PubMed

See these in context on the Vitamin C monograph →

Elderberry 6 references
  1. Barak V, Halperin T, Kalickman I. The effect of Sambucol, a black elderberry-based, natural product, on the production of human cytokines: I. Inflammatory cytokines. Eur Cytokine Netw 2001;12:290-6..
  2. Elderberry (Sambucus species). The Poison Plant Patch, Novia Scotia Museum, 2007. Available at: http://museum.gov.ns.ca/poison/?section=species&id=117 (Accessed 16 October 2009).
  3. European elder. Canadian Poisonous Plants Information System. Available at: http://www.cbif.gc.ca/pls/pp/ppack.jump?p_null=all&p_psn=121&p_type=all&p_sci=comm&p_x=px (Accessed 16 October 2009).
  4. Raus K, Pleschka S, Klein P, Schoop R, Fisher P. Effect of an echinacea-based hot drink versus oseltamivir in Influenza treatment: a randomized, double-blind, double-dummy, multicenter, noninferiority clinical trial. . Curr Ther Res Clin Exp. 2015;20;77:6 PubMed
  5. Ramachandran A, Antala D, Pudasainee P, Panginikkod S, Gupta H. A Plausible Association Between the Use of Elderberry and Autoimmune Hepatitis. Cureus 2022;14(4):e24250. PubMed
  6. Agarwal N, Mangla A. Elderberry interaction with pazopanib in a patient with soft-tissue sarcoma: A case report and literature review. Mol Clin Oncol 2024;20(5):36. PubMed

See these in context on the Elderberry monograph →

Camu Camu 2 references
  1. Vitamin C - Health Professional Fact Sheet — NIH Office of Dietary Supplements Source
  2. Vitamin C — MedlinePlus Source

See these in context on the Camu Camu monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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