Major interaction on record — check this product against your medications before combining. Based on 4 of 5 ingredients. Check your meds →
Dietary supplement

Meta-C 500 mg Capsules Ingredients & Drug Interactions

by NutriBiotic Immunity

Meta-C 500 mg Capsules label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Meta-C 500 mg Capsules 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: Major

Meta-C 500 mg Capsules is a dietary supplement by NutriBiotic Immunity with 5 active ingredients. Its ingredients are commonly taken for common cold and immune support, antioxidant support, skin health and collagen formation.Based on those ingredients, 639 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Spirulina, Vitamin C, Calcium. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Meta-C 500 mg Capsules by NutriBiotic Immunity

Ask about any prescription or over-the-counter medication and we check it for interactions with Meta-C 500 mg Capsules by NutriBiotic Immunity — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Meta-C 500 mg Capsules by NutriBiotic Immunity

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 5 of its 5 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Meta-C 500 mg contains five active ingredients. Vitamin C (and its biologically active metabolites and dehydroascorbic acid form) is the primary immune-supporting ingredient.

Calcium supports bone and overall mineral balance. Spirulina is a blue-green algae used for general wellness.

Lemon bioflavonoid complex is included for its flavonoid content. The capsule itself is made from gelatin and magnesium stearate.

Does it work?

Not established
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
Not established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use.

Why this rating?
  • The label markets this product for: Immune system antioxidant protection and nutrient support.
  • We looked for evidence on: Cardiovascular disease (CVD), Heart failure, Immune function, Collagen formation, Tissue repair.
  • The closest evidence on file: Vitamin C is rated "Possibly Ineffective" for Cardiovascular disease (CVD) (Natural Medicines).
  • Also on file: Calcium is rated "Ineffective" for Cardiovascular disease (CVD).
  • Also on file: Calcium is rated "Insufficient Reliable Evidence To Rate" for Heart failure.

In our data, vitamin C is rated effective for vitamin C deficiency and possibly effective for anemia of chronic disease, atrial fibrillation, cataracts, and exercise-induced respiratory infections. Calcium is rated effective for kidney failure, dyspepsia, and hypocalcemia, and likely effective for osteoporosis.

Spirulina is rated possibly effective for high blood pressure; evidence for acne, hay fever, iron-deficiency anemia, and arsenic poisoning is insufficient. Lemon bioflavonoid complex has insufficient evidence for hay fever, anxiety, respiratory infections, high blood pressure, and kidney stones.

The evidence, ingredient by ingredient Vitamin C Calcium Blue-green Algae Lemon

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 4 of the 4 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 4 of 4.
  • General safety write-ups exist for 4 of 4.
  • 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. At very high doses—above 2 grams daily—side effects like abdominal cramps, heartburn, diarrhea, nausea, and headache are more likely.

Kidney stones have been reported in people prone to them. Calcium is generally safe at recommended amounts; the most common side effects are belching, constipation, diarrhea, and stomach upset.

Spirulina may cause abdominal cramps, bloating, diarrhea, dizziness, fatigue, flatulence, headache, nausea, and vomiting. Rare allergic reactions, including anaphylaxis, have been reported.

Quality and contamination with toxins or heavy metals is a safety concern with spirulina products. Lemon in food amounts is well tolerated; fresh lemon juice at higher doses (60 mL twice daily) caused heartburn in 21% of trial participants and stomach upset in 37% compared to 8% in placebo.

For pregnancy, vitamin C at normal amounts is considered likely safe, but avoid high-dose supplements; calcium is likely safe at recommended amounts; safety data for spirulina and lemon bioflavonoid complex in pregnancy is not on file.

Side effects, ingredient by ingredient Vitamin C Calcium Blue-green Algae Lemon

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.

Why this rating?
  • 4 of the 4 matched ingredients can interact with medications — Lemon, Calcium, Blue-green Algae, Vitamin C.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; cancer treatments; diabetes medications; heart-rhythm medications; lithium.
  • For scale: 639 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.

Check your medications against these drug types before starting: HIV integrase inhibitors (dolutegravir, elvitegravir)—calcium reduces their effectiveness significantly; blood thinners and antiplatelet drugs (warfarin, others)—vitamin C at high doses and spirulina theoretically increase bleeding risk; thyroid medication (levothyroxine)—both vitamin C and calcium affect how much you absorb; chemotherapy drugs (alkylating agents, antitumor antibiotics)—vitamin C's antioxidant effects may reduce their activity; diabetes medications—spirulina may lower blood sugar; heart drugs (sotalol, diltiazem); immunosuppressants; and the antifungal itraconazole. No interactions are documented in our data for the remaining ingredients we were unable to check.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. Major medication interactions have been identified, and safety information is well characterized.

This product is built around vitamin C and calcium for immune and bone support. If you take HIV antiretrovirals, blood thinners, thyroid medication, or chemotherapy, check your exact medications with the tool below first.

Talk with your pharmacist if you're pregnant, breastfeeding, or take any regular prescriptions.

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

Assessment coverage: 5 of 5 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Oct 24, 2024.

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 Meta-C 500 mg Capsules, straight from the product label.

Brand NutriBiotic Immunity
Barcode (UPC) 728177001803
Net contents 100 Capsule(s)
Market status On market
Date entered into DSLD Oct 24, 2024
DSLD ID 315722
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy 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 Meta-C 500 mg Capsules by NutriBiotic Immunity, 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:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
100
UPC/BARCODE
728177001803
IngredientAmount% DV
Vitamin C500 mg555%
Calcium64 mg5%
Biologically Active Metabolites and Dehydroascorbic Acid56 mg--
Spirulina155 mg--
Lemon Bioflavonoid Complex100 mg--

Other ingredients: Gelatin, 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.
Formulation

Rapid Dissolving

Gluten free Made without: GMOs, milk, soy, eggs, yeast, wheat, rose hips, peanuts, tree nuts, fish, crustacean shellfish, fillers, binders, starch, sweeteners, and preservatives. Made with Non-GMO Ingredients

pH 6.2 Measure of acidity/alkalinity (neutral pH is 7.0)

Formula

NutriBiotic Meta-C is a unique, buffered vitamin C with biologically active metabolites from spirulina, a single-called, blue-green algae rich in nutrients. Meta-C Capsules absorb fast and efficiently and contain the added benefits of bioflavonoids from lemons. Meta-C is produced by water-processing vitamin C and calcium with an array of biologically active metabolites at low temperatures. This created a fully reacted calcium ascorbate, which is then combined with spirulina to form an advanced food-bound nutrient system providing all the properties found in concentrated whole foods such as protein, lipids, glycoproteins, lipoproteins, nucleoproteins (RNA/DNA), complex carbohydrates, phytopigments, flavonoids, fatty acids, enzymes, co-enzymes, trace elements, and fiber.

Vitamin C and calcium are essential nutrients that provide antioxidant protection to the immune system as well as maintain the health of blood vessels, tissue, cartilage, bones, eyes, and other organ systems, Vitamin C is also required for the biosynthesis of collagen, L-carnitine and neurotransmitters. The combined positive effects of vitamin C, calcium, spirulina, and bioflavonoids make Meta-C Capsules an excellent choice for supporting the body's overall health.

Buffered vitamin C with biologically active metabolites

Suggested/Recommended/Usage/Directions

Meta-C Capsules are easy-to-swallow or may be emptied into food or beverages if desired. Suggested use: As a dietary supplement, take one capsule daily with or without meals.

FDA Statement of Identity

Dietary Supplement

Seals/Symbols

Not Tested on Animals NitroPak Naturally Fresh Bacteria Free Environment

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

See for yourself

Meta-C 500 mg Capsules by NutriBiotic Immunity label

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

Meta-C 500 mg Capsules 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 Meta-C 500 mg Capsules by NutriBiotic Immunity

These are the 5 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container100 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
500 mg per serving Form: Meta-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...

Vitamin C monograph & interactions

Calcium

Interacts with
168 drugs
64 mg per serving Form: Meta-C

Calcium is an essential mineral your body needs for strong bones, nerve signaling, and muscle function, and supplements can help fill gaps when diet f...

Calcium monograph & interactions

Biologically Active Metabolites and Dehydroascorbic Acid

Interacts with
207 drugs
56 mg per serving Form: Meta-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...

Biologically Active Metabolites and Dehydroascorbic Acid monograph & interactions

Spirulina

Interacts with
327 drugs
155 mg per serving Form: Meta-C

Blue-green algae are nutrient-rich aquatic microorganisms (such as spirulina and Klamath Lake algae) taken as a supplement for energy, nutrition, and...

Spirulina monograph & interactions

Lemon Bioflavonoid Complex

Interacts with
1 drug
100 mg per serving Form: Eriocitrin, Flavones, Flavonols, Hesperidin, Naringenin, Naringin, Phenolic Compounds

Lemon is a common citrus fruit that is a good source of vitamin C and citric acid, and it is widely used in food, drinks, and home remedies. While it...

Lemon Bioflavonoid Complex monograph & interactions

Other (inactive) ingredients: Gelatin, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Meta-C 500 mg Capsules by NutriBiotic Immunity Drug Interactions

Want to check YOUR meds against Meta-C 500 mg Capsules?

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
639Drugs
7 Major 541 Moderate 91 Minor

Ingredients driving the most interactions

Spirulina 327
Vitamin C 207
Calcium 168
Lemon Bioflavonoid Complex 1

Individual Drug Interactions

The ingredients in Meta-C 500 mg Capsules interact with 639 drugs. Click any drug to see the details.

4 of the 5 ingredients in Meta-C 500 mg Capsules interact with drugs. Each result below shows which ingredient is responsible. Spirulina Vitamin C Calcium Lemon Bioflavonoid Complex

Each ingredient & the kinds of drugs it affects

For each ingredient in Meta-C 500 mg Capsules 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.

Spirulina3 drug types · 327 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, spirulina blue-green algae might increase the risk of bleeding if used with other anticoagulant or antiplatelet drugs. However, this is unlikely.
Spirulina blue-green algae have shown antiplatelet and anticoagulant effects in vitro. However, one preliminary study in 24 patients receiving spirulina blue-green algae 2.3 grams daily for 2 weeks showed no effect on platelet activation or measures of clotting time.

Likelihood Unlikely Evidence D
Antidiabetes Drugs

Theoretically, taking blue-green algae with antidiabetes drugs might increase the risk of hypoglycemia.
Human research shows that spirulina blue-green algae can have hypoglycemic effects in patients with diabetes, at least some of whom were using antidiabetes drugs. However, blue-green algae does not seem to improve glycated hemoglobin (HbA1c) levels in patients with diabetes. A meta-analysis of animal studies also suggests that spirulina blue-green algae have hypoglycemic effects.

Likelihood Possible Evidence B
Immunosuppressants

Theoretically, concurrent use of blue-green algae might interfere with immunosuppressive therapy.
Blue-green algae have been shown to stimulate the immune system.

Likelihood Possible Evidence D
Spirulina full monograph & interactions

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

Calcium18 drug types · 168 drugs

Ceftriaxone (Rocephin)

Co-administration of intravenous calcium and ceftriaxone can result in precipitation of a ceftriaxone-calcium salt in the lungs and kidneys.
Avoid administering intravenous calcium in any form, such as parenteral nutrition or Lactated Ringers, within 48 hours of intravenous ceftriaxone. Case reports in neonates show that administering intravenous ceftriaxone and calcium can result in precipitation of a ceftriaxone-calcium salt in the lungs and kidneys. In several cases, neonates have died as a result of this interaction. So far there are no reports in adults; however, there is still concern that this interaction might occur in adults.

Likelihood Probable Evidence D
Dolutegravir (Tivicay)

Calcium seems to reduce levels of dolutegravir.
Advise patients to take dolutegravir either 2 hours before or 6 hours after taking calcium supplements. Pharmacokinetic research suggests that taking calcium carbonate 1200 mg concomitantly with dolutegravir 50 mg reduces plasma levels of dolutegravir by almost 40%. Calcium appears to decrease levels of dolutegravir through chelation.

Likelihood Probable Evidence B
Elvitegravir (Vitekta)

Calcium seems to reduce levels of elvitegravir.
Advise patients to take elvitegravir either 2 hours before or 2 hours after taking calcium supplements. Pharmacokinetic research suggests that taking calcium along with elvitegravir can reduce blood levels of elvitegravir through chelation.

Likelihood Probable Evidence B
Aluminum

Calcium citrate might increase aluminum absorption and toxicity. Other types of calcium do not increase aluminum absorption.
Calcium citrate can increase the absorption of aluminum when taken with aluminum hydroxide. The increase in aluminum levels may become toxic, particularly in individuals with kidney disease. However, the effect of calcium citrate on aluminum absorption is due to the citrate anion rather than calcium cation. Calcium acetate does not appear to increase aluminum absorption.

Likelihood Possible Evidence B
Bictegravir/Emtricitabine/Tenofovir Alafenamide (Biktarvy)

Calcium might decrease levels of bictegravir/emtricitabine/tenofovir alafenamide by reducing its absorption when taken in a fasting state.
Advise patients that bictegravir/emtricitabine/tenofovir alafenamide and calcium can be taken together if taken with food. However, if taken on an empty stomach, bictegravir/emtricitabine/tenofovir alafenamide should not be taken with, or 2 hours after, calcium containing products.

Likelihood Probable Evidence D
Bisphosphonates

Calcium reduces the absorption of bisphosphonates.
Advise patients to take bisphosphonates at least 30 minutes before calcium, but preferably at a different time of day. Calcium supplements decrease absorption of bisphosphonates.

Likelihood Probable Evidence C
Calcipotriene (Dovonex)

Taking calcipotriene with calcium might increase the risk for hypercalcemia.
Calcipotriene is a vitamin D analog used topically for psoriasis. It can be absorbed in sufficient amounts to cause systemic effects, including hypercalcemia. Theoretically, combining calcipotriene with calcium supplements might increase the risk of hypercalcemia.

Likelihood Possible Evidence B
Digoxin (Lanoxin)

Using intravenous calcium with digoxin might increase the risk of fatal cardiac arrhythmias.
Hypercalcemia increases the risk of fatal cardiac arrhythmias with digoxin. However, one retrospective analysis of clinical data suggests that intravenous calcium does not increase the risk of dysrhythmias or mortality in patients receiving digoxin.

Likelihood Possible Evidence B
Diltiazem (Cardizem, Others)

Theoretically, calcium may reduce the therapeutic effects of diltiazem.
Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation. Theoretically, calcium might increase this risk of hypercalcemia and reduce the effectiveness of diltiazem.

Likelihood Probable Evidence D
Levothyroxine (Synthroid, Others)

Calcium seems to reduce the absorption and effectiveness of levothyroxine.
Advise patients to take levothyroxine and calcium supplements at least 4 hours apart. Calcium reduces levothyroxine absorption, probably by forming insoluble complexes. Calcium carbonate supplements reduce effectiveness of levothyroxine in patients with hypothyroidism.

Likelihood Probable Evidence B
Lithium

Theoretically, concomitant use of calcium and lithium may increase this risk of hypercalcemia.
Clinical research suggests that long-term use of lithium may cause hypercalcemia in 10% to 60% of patients. Theoretically, concomitant use of lithium and calcium supplements may further increase this risk.

Likelihood Possible Evidence B
Quinolone Antibiotics

Calcium seems to reduce the absorption of quinolone antibiotics.
Advise patients to take oral quinolones at least 2 hours before or 4-6 hours after calcium supplements or calcium-fortified foods. Taking calcium at the same time as oral quinolones can reduce quinolone absorption. Calcium binds to quinolones in the gut.

Likelihood Probable Evidence B
Raltegravir (Isentress)

Calcium may reduce levels of raltegravir.
Pharmacokinetic research shows that taking a single dose of calcium carbonate 3000 mg along with raltegravir 400 mg twice daily modestly decreases the mean area under the curve of raltegravir, but the decrease does not necessitate a dose adjustment of raltegravir. However, a case of elevated HIV-1 RNA levels and documented resistance to raltegravir has been reported for a patient taking calcium carbonate 1 gram three times daily plus vitamin D3 (cholecalciferol) 400 IU three times daily in combination with raltegravir 400 mg twice daily for 11 months. It is thought that calcium reduced raltegravir levels by chelation, leading to treatment failure.

Likelihood Possible Evidence B
Sotalol (Betapace)

Calcium seems to reduce the absorption of sotalol.
Advise patients to separate doses by at least 2 hours before or 4-6 hours after calcium. Calcium appears to reduce the absorption of sotalol, probably by forming insoluble complexes.

Likelihood Possible Evidence B
Tetracycline Antibiotics

Calcium seems to reduce the absorption of tetracycline antibiotics.
Advise patients to take oral tetracyclines at least 2 hours before, or 4-6 hours after calcium supplements. Taking calcium at the same time as oral tetracyclines can reduce tetracycline absorption. Calcium binds to tetracyclines in the gut.

Likelihood Probable Evidence C
Thiazide Diuretics

Taking calcium along with thiazides might increase the risk of hypercalcemia and renal failure.
Thiazides reduce calcium excretion by the kidneys. Using thiazides along with moderately large amounts of calcium carbonate increases the risk of milk-alkali syndrome (hypercalcemia, metabolic alkalosis, renal failure). Patients may need to have their serum calcium levels and/or parathyroid function monitored regularly.

Likelihood Probable Evidence C
Verapamil (Calan, Others)

Theoretically, calcium may reduce the therapeutic effects of verapamil.
Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation. Theoretically, use of calcium supplements may increase this risk of hypercalcemia and reduce the effectiveness of verapamil.

Likelihood Probable Evidence D
Calcium Channel Blockers

Intravenous calcium may decrease the effects of calcium channel blockers; oral calcium is unlikely to have this effect.
Intravenous calcium is used to decrease the effects of calcium channel blockers in the management of overdose. Intravenous calcium gluconate has been used before intravenous verapamil (Isoptin) to prevent or reduce the hypotensive effects without affecting the antiarrhythmic effects. But there is no evidence that dietary or supplemental calcium when taken orally interacts with calcium channel blockers.

Likelihood Unlikely Evidence D
Calcium full monograph & interactions

Lemon Bioflavonoid Complex1 drug type · 1 drug

Itraconazole (Sporanox)

Theoretically, taking itraconazole capsules or tablets with a beverage containing lemon might increase the levels and clinical effects of itraconazole.
In one case report, dissolving itraconazole tablets in a small amount of specific beverages containing lemon prior to administration increased the level of itraconazole in a lung transplant patient. In this case, the increased bioavailability was desirable and was likely due to improved tablet dissolution in the acidic beverage.

Likelihood Possible Evidence D
Lemon Bioflavonoid Complex full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Meta-C 500 mg Capsules, from the product label.

NutriBiotic Immunity

See all NutriBiotic Immunity products
Name
NutriBiotic
Street Address
P.O. Box 238
City
Lakeport
State
CA
ZipCode
95453
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Pharmacist Counseling Corner

Meta-C 500 mg Capsules by NutriBiotic Immunity: Common Questions

Does Meta-C 500 mg Capsules by NutriBiotic Immunity interact with any medications?
Yes. Based on its ingredients, Meta-C 500 mg Capsules has a known interaction with 639 medications, including 7 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Meta-C 500 mg Capsules contains 5 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 or hormone therapy?
Vitamin C in this product may increase estrogen levels by up to 55% in some cases. Talk with your pharmacist or doctor about whether this matters for your specific birth control or hormone regimen.
Is spirulina safe?
Spirulina is generally well tolerated but carries a quality and contamination concern—some products have tested positive for toxins or heavy metals. Rare allergic reactions, including serious ones, have been reported. The safety data on spirulina supplements is limited.
What are the common side effects?
Vitamin C at normal doses is well tolerated but can cause abdominal cramps, heartburn, diarrhea, nausea, and headache at higher doses. Calcium commonly causes belching, constipation, or diarrhea. Spirulina may cause bloating, diarrhea, nausea, fatigue, and headache.
Will this help my immune system?
Vitamin C is effective for vitamin C deficiency and possibly effective for exercise-induced respiratory infections. The evidence for spirulina and lemon bioflavonoid complex for immunity is either insufficient or not established in our data.
Is it safe to take this while pregnant?
Vitamin C at normal amounts from food and prenatal vitamins is considered likely safe, but avoid high-dose supplements unless your doctor advises otherwise. Calcium at recommended amounts is likely safe. We don't have enough safety data on spirulina and lemon bioflavonoid complex in pregnancy—talk with your doctor or pharmacist.
Can I take this with my levothyroxine (thyroid medicine)?
Both vitamin C and calcium in this product can affect how much levothyroxine your body absorbs. Separate your levothyroxine and calcium by at least 4 hours. Check with your pharmacist about timing with this product.

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.

Meta-C 500 mg Capsules label
Go deeper

The Full Monographs Behind Meta-C 500 mg Capsules’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

Calcium

Interacts with 168 drugs

Calcium is an essential mineral your body needs for strong bones, nerve signaling, and muscle function, and supplements can help fill gaps when diet falls short. Most people do best getting...

Read the full Calcium monograph → Herb & supplement monograph

Blue-green Algae

Interacts with 327 drugs

Blue-green algae are nutrient-rich aquatic microorganisms (such as spirulina and Klamath Lake algae) taken as a supplement for energy, nutrition, and general wellness. Evidence for most heal...

Read the full Blue-green Algae monograph → Herb & supplement monograph

Lemon

Interacts with 1 drug

Lemon is a common citrus fruit that is a good source of vitamin C and citric acid, and it is widely used in food, drinks, and home remedies. While it can support hydration and a healthy diet...

Read the full Lemon monograph →
Sources

Sources & How We Checked

Meta-C 500 mg Capsules'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 137 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
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  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
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  7. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
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  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/.
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  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
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  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
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  19. Mc Leod DC, Nahata MC. Inefficacy of ascorbic acid as a urinary acidifier (letter). N Engl J Med 1977;296:1413. DOI
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  21. Dysken MW, Cumming RJ, Channon RA, Davis JM. Drug interaction between ascorbic acid and fluphenazine. JAMA 1979;241:2008. DOI
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  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
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  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
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  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
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  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 →

Calcium 62 references
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See these in context on the Calcium monograph →

Blue-green Algae 22 references
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  14. Rzymski P, Niedzielski P, Kaczmarek N, Jurczak T, Klimaszyk P. The multidisciplinary approach to safety and toxicity assessment of microalgae-based food supplements following clinical cases of poisoning. Harmful Algae 2015;46:34-42. DOI
  15. Petrus M, Culerrier R, Campistron M, et al. First case report of anaphylaxis to spirulin: identification of phycocyanin as responsible allergen. Allergy 2010;65(7):924-5. PubMed
  16. Marles RJ, Barrett ML, Barnes J, et al. United States Pharmacopeia safety evaluation of spirulina. Crit Rev Food Sci Nutr 2011;51(7):593-604. PubMed
  17. Majdoub H, Ben Mansour M, Chaubet F, et al. Anticoagulant activity of a sulfated polysaccharide from the green alga Arthrospira platensis. Biochim Biophys Acta 2009;1790(10):1377-81. PubMed
  18. Cha BG, Kwak HW, Park AR, et al. Structural characteristics and biological performance of silk fibroin nanofiber containing microalgae spirulina extract. Biopolymers 2014;101(4):307-18. PubMed
  19. Jensen GS, Drapeau C, Lenninger M, Benson KF. Clinical safety of a high dose of phycocyanin-enriched aqueous extract from Arthrospira (Spirulina) platensis: results from a randomized, double-Blind, placebo-controlled study with a focus on anticoagulant ac
  20. Hamedifard Z, Milajerdi A, Reiner Z, Taghizadeh M, Kolahdooz F, Asemi Z. The effects of spirulina on glycemic control and serum lipoproteins in patients with metabolic syndrome and related disorders: A systematic review and meta-analysis of randomized con
  21. Moradi S, Zobeiri M, Feizi A, Clark CCT, Entezari MH. The effects of spirulina (Arthrospira platensis) supplementation on anthropometric indices, blood pressure, sleep quality, mental health, fatigue status and quality of life in patients with ulcerative
  22. Ghanbari F, Amerizadeh A, Behshood P, Moradi S, Asgary S. Effect of microalgae arthrospira on biomarkers of glycemic control and glucose metabolism: a systematic Review and meta-analysis. Curr Probl Cardiol 2022;47(10):100942. PubMed

See these in context on the Blue-green Algae monograph →

Lemon 2 references
  1. Ruggenenti P, Caruso MR, Cortinovis M, et al. Fresh lemon juice supplementation for the prevention of recurrent stones in calcium oxalate nephrolithiasis: A pragmatic, prospective, randomised, open, blinded endpoint (PROBE) trial. EClinicalMedicine 2021;4 PubMed
  2. Umemura K, Katada Y, Nakagawa S, et al. Improved absorption of itraconazole tablet by co-administration with lemon beverages in a lung transplant recipient: A case report. J Infect Chemother 2022;28(8):1203-1207. PubMed

See these in context on the Lemon 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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