Interactions on record — worth a quick check against your medications. Based on 3 of 4 ingredients. Check your meds →
Dietary supplement

Vitamin C Plus Ingredients & Drug Interactions

by Carotec

Vitamin C Plus label
See full label image
Capsule Category: Botanical With Nutrients
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Vitamin C Plus 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

Vitamin C Plus is a dietary supplement by Carotec with 4 active ingredients. Its ingredients are commonly taken for common cold and immune support, antioxidant support, skin health and collagen formation.Based on those ingredients, 1,121 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Masquelier's Grape OPC, Oligopin, Quali-C. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Vitamin C Plus by Carotec

Ask about any prescription or over-the-counter medication and we check it for interactions with Vitamin C Plus by Carotec — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Vitamin C Plus by Carotec

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 11, 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 4 of its 4 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Vitamin C Plus contains four active ingredients. Quali-C is a form of vitamin C, a nutrient that helps your body fight infections and heal wounds.

Oligopin is maritime pine bark extract, used for circulation and joint health. Masquelier's Grape OPC and Resveravine are both grape-derived compounds that work as antioxidants.

The capsule also contains two inactive ingredients — cellulose and ascorbyl palmitate — which are used as a binder and preservative.

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?
  • The label markets general wellness (“Antioxidant support and general wellness”), not a specific health condition, so there is no single claim to grade against clinical-evidence data.
  • Since the label doesn't commit to one use, we graded the ingredients' overall clinical evidence instead.
  • On file: Vitamin C deficiency — rated "Effective" (Vitamin C) (Natural Medicines).
  • On file: Anemia of chronic disease — rated "Possibly Effective" (Vitamin C) (Natural Medicines).
  • On file: Asthma — rated "Possibly Effective" (Maritime Pine) (Natural Medicines).
  • On file: Atrial fibrillation — rated "Possibly Effective" (Vitamin C) (Natural Medicines).
  • On file: Cataracts — rated "Possibly Effective" (Vitamin C) (Natural Medicines).

Vitamin C is effective for preventing and treating vitamin C deficiency. It's possibly effective for anemia of chronic disease, atrial fibrillation, cataracts, and exercise-induced respiratory infections, though the evidence is limited.

Maritime pine and the grape ingredients are possibly effective for chronic venous insufficiency (CVI) — a condition affecting how blood flows back up your legs — but evidence for other uses is either limited or shows they may not be effective at all. The data we hold doesn't establish effectiveness for most other conditions you might consider this product for.

The evidence, ingredient by ingredient Vitamin C Maritime Pine Grape

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.

Vitamin C is generally well tolerated at normal doses, but very high doses — above 2 grams daily — can cause side effects including stomach cramps, heartburn, diarrhea, nausea, and headache. In people prone to kidney stones, high doses have caused them.

Maritime pine and grape extracts appear generally well tolerated in studies, though some people report stomach complaints, dizziness, headache, joint pain, or nausea. Rare cases of heart-related chest pain and heart failure have been reported with maritime pine, though it's unclear if the supplement caused them.

Very high-dose intravenous vitamin C has rarely caused serious kidney damage. During pregnancy, avoid high-dose vitamin C supplements unless your doctor advises otherwise; normal dietary amounts are fine.

Concentrated grape supplements should be avoided in pregnancy due to limited safety data. Maritime pine hasn't been studied enough in pregnancy or while breastfeeding — talk with your doctor before using it if you're pregnant or nursing.

Side effects, ingredient by ingredient Vitamin C Maritime Pine Grape

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 — Grape, Vitamin C, Maritime Pine.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; cancer treatments; diabetes medications.
  • For scale: 1,122 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 Vitamin C Plus, check these medication types with your pharmacist: blood thinners and antiplatelet drugs (Moderate risk of increased bleeding), estrogen-based medications like birth control and hormone replacement therapy (Moderate risk of elevated hormone levels), chemotherapy drugs that work through free radicals (Moderate risk of reduced effectiveness), immunosuppressants (Moderate risk of decreased effectiveness or increased bleeding), antidiabetes medications (Moderate risk of low blood sugar), thyroid medication — which may need dose adjustment (Moderate), and medications processed through your liver's cytochrome P450 enzymes, including antidepressants, sedatives, and HIV drugs (Moderate). If you take aluminum-containing products or the blood thinner warfarin specifically, the risk is higher.

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.

This product may help with vitamin C deficiency and possibly with circulation issues, but it has significant interactions with blood thinners, hormone medications, several chemotherapy drugs, and many others. If you take any prescription medications — especially blood thinners, birth control, thyroid medication, or immunosuppressants — check each one with the tool below before you start.

Keep doses moderate, and talk to your pharmacist if you're pregnant, planning to become pregnant, or breastfeeding.

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

Assessment coverage: 4 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated May 24, 2023.

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 Vitamin C Plus, straight from the product label.

Brand Carotec
Net contents 60 Capsule(s)
Market status On market
Date entered into DSLD May 24, 2023
DSLD ID 282146
Product type Botanical With Nutrients
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
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 Vitamin C Plus by Carotec, 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 Capsule(s)
Maximum serving Sizes:
4 Capsule(s)
Servings per container
30
IngredientAmount% DV
Quali-C1000 mg1667%
Oligopin50 mg--
Masquelier's Grape OPC50 mg--
Resveravine20 mg--

Other ingredients: Cellulose, Ascorbyl Palmitate

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 two (2) capsules per day. Advanced use: Adults may gradually increase to four (4) capsules per day.

Precautions

Warning: Keep out of reach of children.

If you are pregnant, nursing or taking medication, consult your doctor before use.

Discontinue use and consult your doctor if adverse reactions occur.

Brand IP Statement(s)

Quali-C is a registered trademark of DSM, Switzerland. Oligopin is a registered trademark of PurextractDRT, France. Masquelier's is a registered trademark of international nutrition company, BV. Resveravine is a registered trademark of Nexira, France.

FDA Disclaimer Statement

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.

FDA Statement of Identity

Dietary Supplement

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

See for yourself

Vitamin C Plus by Carotec label

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

Vitamin C Plus 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 Vitamin C Plus by Carotec

These are the 4 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 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.

Quali-C

Interacts with
207 drugs
1000 mg per serving Form: Vitamin C

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...

Quali-C monograph & interactions

Oligopin

Interacts with
327 drugs
50 mg per serving Form: French Maritime Pine

Maritime pine bark extract (often sold as Pycnogenol) is a plant-based antioxidant most studied for circulation, vein, and skin health. Some research...

Oligopin monograph & interactions

Masquelier's Grape OPC

Interacts with
910 drugs
50 mg per serving Form: Oligomeric Procyanidins, OPC Precursors, Polyphenols

Grapes and grape products like grape seed extract contain antioxidant compounds such as resveratrol and proanthocyanidins that may support heart and b...

Masquelier's Grape OPC monograph & interactions

Resveravine

Interacts with
910 drugs
20 mg per serving Form: Grapevine, Oligostibens, Trans-Resveratrol

Grapes and grape products like grape seed extract contain antioxidant compounds such as resveratrol and proanthocyanidins that may support heart and b...

Resveravine monograph & interactions

Other (inactive) ingredients: Cellulose, Ascorbyl Palmitate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Vitamin C Plus by Carotec Drug Interactions

Want to check YOUR meds against Vitamin C Plus?

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
1,121Drugs
1,084 Moderate 37 Minor

Ingredients driving the most interactions

Masquelier's Grape OPC 910
Oligopin 327
Quali-C 207

Individual Drug Interactions

The ingredients in Vitamin C Plus interact with 1,121 drugs. Click any drug to see the details.

3 of the 4 ingredients in Vitamin C Plus interact with drugs. Each result below shows which ingredient is responsible. Masquelier's Grape OPC Oligopin Quali-C

Each ingredient & the kinds of drugs it affects

For each ingredient in Vitamin C Plus 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.

Masquelier's Grape OPC9 drug types · 910 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, grape extracts may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
In vitro evidence suggests that grape extracts might decrease platelet aggregation.

Likelihood Possible Evidence D
Cyclosporine (Neoral, Sandimmune)

Ingesting grape juice with cyclosporine can reduce cyclosporine absorption.
A small pharmacokinetic study in healthy young adults shows that intake of purple grape juice 200 mL along with cyclosporine can decrease the absorption of cyclosporine by up to 30% when compared with water. Separate doses of grape juice and cyclosporine by at least 2 hours to avoid this interaction.

Likelihood Possible Evidence B
Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, grape juice might reduce the levels of CYP1A2 substrates.
A small pharmacokinetic study in healthy adults shows that ingestion of 200 mL of grape juice decreases phenacetin plasma levels. This is thought to be due to induction of CYP1A2.

Likelihood Possible Evidence B
Cytochrome P450 2D6 (Cyp2D6) Substrates

Theoretically, grape seed extract may increase the levels of CYP2D6 substrates.
In vitro evidence suggests that grape seed extract might inhibit CYP2D6 enzymes. However, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2E1 (Cyp2E1) Substrates

Theoretically, grape seed extract might increase the levels of CYP2E1 substrates.
In vitro and animal research suggests that grape seed proanthocyanidin extract inhibits CYP2E1 enzymes. However, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

It is unclear if grape seed extract inhibits or induces CYP3A4; research is conflicting.
In vitro evidence suggests that grape seed extract might inhibit CYP3A4 enzymes. However, evidence from animal research shows that grape seed extract may induce CYP3A4 in the liver. So far, these interactions have not been reported in humans.

Likelihood Possible Evidence D
Midazolam (Versed)

Theoretically, long-term intake of grape seed extract might decrease the effects of midazolam.
Animal research shows that subchronic ingestions of grape seed extract can increase the elimination of intravenous midazolam by increasing hepatic CYP3A4 activity. Single doses of grape seed extract do not appear to affect midazolam elimination.

Likelihood Possible Evidence D
Phenacetin

Grape juice might decrease phenacetin absorption.
A small pharmacokinetic study in healthy adults shows that ingestion of 200 mL of grape juice decreases phenacetin plasma levels. This is thought to be due to induction of cytochrome P450 1A2 (CYP1A2).

Likelihood Possible Evidence B
Cytochrome P450 2C9 (Cyp2C9) Substrates

It is unclear if grape juice or grape seed extract inhibits CYP2C9; research is conflicting.
In vitro evidence shows that grape seed extract or grape juice might inhibit CYP2C9 enzymes. However, a small pharmacokinetic study in healthy adults shows that drinking 8 ounces of grape juice once does not affect the clearance of flurbiprofen, a probe-drug for CYP2C9 metabolism. The effects of continued grape juice consumption are unclear.

Likelihood Unlikely Evidence D
Masquelier's Grape OPC full monograph & interactions

Oligopin3 drug types · 327 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, maritime pine bark extract might increase the risk of bleeding when used with antiplatelet or anticoagulant drugs.
Clinical research suggests that maritime pine bark extract inhibits platelet aggregation. However, the clinical significance of this effect is unclear.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, maritime pine bark extract might increase the risk of hypoglycemia when used with antidiabetes drugs.
One clinical study shows that maritime pine bark extract decreases blood sugar in patients with diabetes being treated with antidiabetes agents. Monitor blood glucose levels closely. Dose adjustments might be necessary.

Likelihood Possible Evidence B
Immunosuppressants

Theoretically, maritime pine bark extract might decrease the effectiveness of immunosuppressant therapy.
In vitro and animal research suggests that maritime pine bark extract has immunostimulant activity. This effect has not been reported in humans.

Likelihood Possible Evidence D
Oligopin full monograph & interactions

Quali-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
Quali-C full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Vitamin C Plus, from the product label.

Carotec

See all Carotec products
Name
Carotec, Inc.
Street Address
P.O. Box 9919
City
Naples
State
FL
ZipCode
34101
Phone Number
1-800-522-4279
Web Address
www.carotec.com
Pharmacist Counseling Corner

Vitamin C Plus by Carotec: Common Questions

Does Vitamin C Plus by Carotec interact with any medications?
Yes. Based on its ingredients, Vitamin C Plus has a known interaction with 1,121 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Vitamin C Plus contains 4 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 this if I'm on birth control?
Vitamin C in this product may increase how much estrogen your body absorbs from birth control pills, potentially raising hormone levels by up to 55% in some cases. This is a Moderate-level concern. Talk with your doctor or pharmacist before starting — they may need to monitor you or adjust your dose.
Will this help my immune system?
Vitamin C does help your immune system, and it's effective for preventing and treating vitamin C deficiency. The evidence on grape and maritime pine for immunity specifically isn't strong enough in the data we hold. If you think you're deficient in vitamin C, it can help; otherwise, talk to your pharmacist about whether this combination is right for your needs.
What side effects should I watch for?
At normal doses, most people tolerate it well. Above 2 grams of vitamin C daily, you might get stomach cramps, heartburn, diarrhea, nausea, or headache. The grape and maritime pine ingredients can cause stomach upset, dizziness, joint pain, or headache in some people. If you're prone to kidney stones, high doses of vitamin C are a risk.
Is it safe to take while pregnant?
Normal amounts of vitamin C from food and prenatal vitamins are fine, but high-dose vitamin C supplements should be avoided in pregnancy unless your doctor says otherwise. Concentrated grape supplements aren't recommended in pregnancy due to limited safety data. Talk with your doctor before starting, especially if you're taking other supplements.
Can I take this with blood thinners like warfarin?
No, without talking to your doctor first. High-dose vitamin C can reduce warfarin's effectiveness, and the grape ingredients may increase bleeding risk. These are Moderate interactions that need professional review. Your doctor may need to monitor your clotting or adjust doses.
Does this help with vein problems?
The maritime pine and grape ingredients are possibly effective for chronic venous insufficiency, a condition that affects circulation in your legs. That's the strongest evidence for this product. For other circulatory issues, the evidence is limited or absent.

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.

Vitamin C Plus label
Go deeper

The Full Monographs Behind Vitamin C Plus’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

Maritime Pine

Interacts with 327 drugs

Maritime pine bark extract (often sold as Pycnogenol) is a plant-based antioxidant most studied for circulation, vein, and skin health. Some research is promising, but many studies are small...

Read the full Maritime Pine monograph → Herb & supplement monograph

Grape

Interacts with 910 drugs

Grapes and grape products like grape seed extract contain antioxidant compounds such as resveratrol and proanthocyanidins that may support heart and blood vessel health. While the food is he...

Read the full Grape monograph →
Sources

Sources & How We Checked

Vitamin C Plus'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 99 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
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See these in context on the Vitamin C monograph →

Maritime Pine 14 references
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See these in context on the Maritime Pine monograph →

Grape 34 references
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  12. de Lange, D. W., Scholman, W. L., Kraaijenhagen, R. J., Akkerman, J. W., and van de Wiel, A. Alcohol and polyphenolic grape extract inhibit platelet adhesion in flowing blood. Eur.J Clin.Invest 2004;34(12):818-824. PubMed
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  30. Brito, FF., Martinez, A., Palacios, R., Mur, P., Gomez, E., Galindo, P. A., Borja, J., and Martinez, J. Rhinoconjunctivitis and asthma caused by vine pollen: a case report. J Allergy Clin Immunol 1999;103(2 Pt 1):262-266. PubMed
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See these in context on the Grape monograph →

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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.

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