Mega-D3 Ingredients & Drug Interactions
by Schiff
What is this page for?
First and foremost: checking Mega-D3 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
Mega-D3 is a dietary supplement by Schiff with 2 active ingredients. Its ingredients are commonly taken for bone health and osteoporosis, correcting vitamin d deficiency, immune system support.Based on those ingredients, 889 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Vitamin D3. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against Mega-D3 by Schiff
Ask about any prescription or over-the-counter medication and we check it for interactions with Mega-D3 by Schiff — and tell you which ingredient is responsible.
AI summaries are generated from our interaction database for education only — always confirm with your pharmacist. How we use AI
Ask the Pharmacist
A licensed pharmacist will answer your question by email — free, usually within 24 hours.
Got it — thank you!
A licensed pharmacist will answer within 24 hours. Keep an eye on your email (worth checking spam, just in case).
HelloPharmacist Scorecard of Mega-D3 by Schiff
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.
What’s inside
Low disclosure
Mega-D3 contains four active ingredients: Vitamin D3 (the form of vitamin D your body uses), resveratrol (a polyphenol from red wine), red wine extract, and Red Wine Complex Blend. These are paired with inactive ingredients — soybean oil, gelatin, and several color and texture agents — that make up the softgel capsule.
The red wine components and resveratrol are included for their antioxidant properties, though the effectiveness of each varies.
Does it work?
Couldn't assess
Resveratrol, the main active ingredient we have effectiveness data for, shows mixed results. It's rated possibly effective for obesity and allergic rhinitis (hay fever), but possibly ineffective for cardiovascular disease and high cholesterol.
The product facts don't provide an effectiveness rating for Vitamin D3 or the red wine components in this specific product, so we can't speak to those here.
How safe is it?
Well-documented data
Resveratrol is generally well tolerated at typical supplement doses, but higher doses may cause digestive upset — mainly diarrhea, loose stools, and gastrointestinal discomfort. Long-term safety at concentrated doses isn't fully established.
For pregnancy and breastfeeding, there isn't enough safety information; the safety notes advise against concentrated resveratrol supplements during pregnancy and to avoid supplement use while breastfeeding. A small number of users have reported headache, fatigue, or a rash, though these are uncommon.
Meds to double-check
Moderate interaction found
Check your medications against resveratrol's interactions before you start. The biggest concern is blood thinners and antiplatelet drugs — resveratrol may increase bleeding risk.
Also double-check any prescription that's metabolized by CYP2C19, CYP1A2, CYP3A4, or CYP2E1 liver enzymes, as resveratrol may theoretically raise their levels. Use the checker on this page with your exact medication names.
The bottom line
Scorecard at a glanceFormula with limited ingredient disclosure with no assessable stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.
Mega-D3 is worth considering if you're interested in vitamin D and resveratrol's potential effects on hay fever or weight management. If you take blood thinners, antiplatelet drugs (like aspirin), or any medication metabolized by liver enzymes, check your specific medications with our tool before starting.
Talk to your pharmacist about whether this product fits your health picture.
Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI
Assessment coverage: 2 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Oct 22, 2016.
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
General information
Key facts about Mega-D3, straight from the product label.
| Brand | Schiff |
|---|---|
| Barcode (UPC) | 020525101686 |
| Net contents | 90 Softgel(s) |
| Market status | On market |
| Date entered into DSLD | Oct 22, 2016 |
| DSLD ID | 65590 |
| Product type | Other Combinations |
| Supplement form | Softgel Capsule |
| Dietary claims / uses | Nutrient, All Other, Structure/Function |
| Intended target group(s) | Adult (18 - 50 Years) |
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 Mega-D3 by Schiff, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| Maltodextrin | 0 NP | -- |
| Vitamin D3 | 5000 IU | 1250% |
| Red Wine Complex Blend | 200 mg | -- |
| Red Wine extract | 0 NP | -- |
| Resveratrol | 0 NP | -- |
Other ingredients: Soybean Oil, Gelatin, Glycerin, yellow Beeswax, Water, Soy Lecithin, Red 40, Titanium Dioxide, Caramel color, Blue 1, Sulfur Dioxide
Tap any ingredient to jump to its full detail below.
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.
General Statements
Since 1936
Over 75 years of wellness
Actual size
GUARANTEED for purity, freshness and labeled potency.
New look
For information call: 1-800-526-6251 (8am-5pm MST M–F)
400 IU Vitamin D is 100% of the recommended daily value. However, many health benefits have been found at doses greater than 400 IU.
All ingredients are provided in one easy-to-swallow softgel. Extensive research has found that high amounts of Vitamin D support cardiovascular health and promote bone & muscle strength. Vitamin D3 is the natural form of Vitamin D and is more powerful than Vitamin D2.
For scientific study results, go to www.vitaminDcouncil.org
Vitamin D3 promotes overall health & wellness*
Formula
5000 IU of Vitamin D3
High Potency Vitamin D3 with Resveratrol & Red Wine Extract
Contains soy.
Mega-D3 is a supplement that contains Vitamin D3, Resveratrol and Red Wine Extract.
Each Mega-D3 softgel provides the same amount of Resveratrol found in several glasses of Red Wine.
High potency Vitamin D3 & more
Plus Resveratrol & Red Wine Extract
Suggested/Recommended/Usage/Directions
Just 1 softgel per day
Directions: For best results, take one (1) softgel daily.
Formulation
GUARANTEED: No added sugar (sucrose, fructose, lactose), salt (sodium chloride), yeast, wheat, gluten or milk. No artificial flavors.
Mega-D3 helps you get the health benefits of Red Wine without the alcohol and calories.
Seals/Symbols
Schiff Quality Guarantee
Brand IP Statement(s)
Like all Schiff products, Mega-D3 is manufactured under strict conditions of quality control. We guarantee it.
Precautions
Contains soy.
Keep out of reach of children.
NOTE: If you are pregnant, lactating or on prescribed medication, consult your physician before using.
Storage
Store in a cool, dry place with lid tightly closed.
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.
General
10168 46010168.7
FDA Statement of Identity
Dietary Supplement
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
Mega-D3 by Schiff label
The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.
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)The Ingredients in Mega-D3 by Schiff
These are the 2 active ingredients this product is made of. Select any to open its full monograph.
Serving size1 Softgel(s) Dosage formSoftgel Capsule 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 D3
Interacts with715 drugs
Vitamin D is a fat-soluble vitamin that helps your body absorb calcium and is important for healthy bones, muscles, and immune function. Many people,...
Vitamin D3 monograph & interactions- › Maltodextrin
- › Red Wine extract
- › Resveratrol
Red Wine Complex Blend
Other (inactive) ingredients: Soybean Oil, Gelatin, Glycerin, Yellow Beeswax, Water, Soy Lecithin, Red 40, Titanium Dioxide, Caramel color, Blue 1, Sulfur Dioxide. These complete the product’s ingredient list but are not active constituents.
Mega-D3 by Schiff Drug Interactions
HelloPharmacist Interaction Report
Mega-D3 by Schiff contains resveratrol, which has documented interactions with several medication types.
The most serious concern is with blood thinners and antiplatelet drugs (like warfarin and aspirin): resveratrol may have antiplatelet effects and could increase bleeding risk if you're already on these medications.
Read the full breakdown — every affected drug type, severity by severity
Resveratrol may also theoretically increase blood levels of drugs metabolized by your liver's CYP enzymes — specifically CYP2C19, CYP1A2, CYP3A4, and CYP2E1 substrates. These are Moderate-severity interactions based on lab research, though human clinical reports are limited.
The one human study (using a much higher dose of resveratrol) found no dose adjustment was needed for CYP3A4 drugs, but we can't generalize that to all enzyme inhibitors or to this product's dose.
We could not check Maltodextrin, Red Wine Complex Blend, or Red Wine extract — we hold no data for those ingredients. Altogether, these interactions span 812 individual medications.
Use the medication checker below to see if any of your prescriptions are affected before you start.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against Mega-D3?
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 checkerIngredients driving the most interactions
Individual Drug Interactions
The ingredients in Mega-D3 interact with 889 drugs. Click any drug to see the details.
1 of the 2 ingredients in Mega-D3 interact with drugs. Each result below shows which ingredient is responsible. Vitamin D3
Aluminum Hydroxide, Magnesium Hydroxide (otc Drug)Maalox, Mucogel
How Aluminum Hydroxide, Magnesium Hydroxide (otc Drug) interacts with Mega-D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin D3Aluminum Moderate
Interaction Summary
Vitamin D might increase aluminum absorption and toxicity, but this has only been reported in people with renal failure.
Read the full Vitamin D3 + Aluminum Hydroxide, Magnesium Hydroxide (otc Drug) interactionAluminum Hydroxide, Magnesium Hydroxide, Simethicone (otc Drug)Mylanta
How Aluminum Hydroxide, Magnesium Hydroxide, Simethicone (otc Drug) interacts with Mega-D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin D3Aluminum Moderate
Interaction Summary
Vitamin D might increase aluminum absorption and toxicity, but this has only been reported in people with renal failure.
Read the full Vitamin D3 + Aluminum Hydroxide, Magnesium Hydroxide, Simethicone (otc Drug) interactionAluminum, CalciumDomeboro
How Aluminum, Calcium interacts with Mega-D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin D3Aluminum Moderate
Interaction Summary
Vitamin D might increase aluminum absorption and toxicity, but this has only been reported in people with renal failure.
Read the full Vitamin D3 + Aluminum, Calcium interactionAluminum, Magnesium (otc Drug)Almagel
How Aluminum, Magnesium (otc Drug) interacts with Mega-D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin D3Aluminum Moderate
Interaction Summary
Vitamin D might increase aluminum absorption and toxicity, but this has only been reported in people with renal failure.
Read the full Vitamin D3 + Aluminum, Magnesium (otc Drug) interactionAluminum, Magnesium Hydroxide (otc Drug)Wingel
How Aluminum, Magnesium Hydroxide (otc Drug) interacts with Mega-D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin D3Aluminum Moderate
Interaction Summary
Vitamin D might increase aluminum absorption and toxicity, but this has only been reported in people with renal failure.
Read the full Vitamin D3 + Aluminum, Magnesium Hydroxide (otc Drug) interactionAmbrisentanLetairis, Volibris
How Ambrisentan interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
Read the full Resveratrol + Ambrisentan interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Ambrisentan interactionAmiloride, HydrochlorothiazideAmil-Co, Amilzide, Moduret 25, Moduretic
How Amiloride, Hydrochlorothiazide interacts with Mega-D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin D3Thiazide Diuretics Moderate
Interaction Summary
Theoretically, taking thiazide diuretics and high-dose vitamin D can increase the risk of hypercalcemia.
Read the full Vitamin D3 + Amiloride, Hydrochlorothiazide interactionAmiodaroneCordarone, Pacerone
How Amiodarone interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
Read the full Resveratrol + Amiodarone interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Amiodarone interactionAmitriptylineElavil
How Amitriptyline interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 3a4 (cyp3a4) Substrates, Cytochrome P450 2c19 (cyp2c19) Substrates +1 Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
Read the full Resveratrol + Amitriptyline interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Amitriptyline interactionAmitriptyline, ChlordiazepoxideLimbitrol DS
How Amitriptyline, Chlordiazepoxide interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 2c19 (cyp2c19) Substrates, Cytochrome P450 1a2 (cyp1a2) Substrates +1 Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP2C19.
Read the full Resveratrol + Amitriptyline, Chlordiazepoxide interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Amitriptyline, Chlordiazepoxide interactionAmitriptyline, PerphenazineEtrafon, Etrafon-A, Etrafon-Forte, Triavil
How Amitriptyline, Perphenazine interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 3a4 (cyp3a4) Substrates, Cytochrome P450 2c19 (cyp2c19) Substrates +1 Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
Read the full Resveratrol + Amitriptyline, Perphenazine interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Amitriptyline, Perphenazine interactionAmlodipineNorliqva
How Amlodipine interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
Read the full Resveratrol + Amlodipine interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Amlodipine interactionAmlodipine BenzoateKaterzia
How Amlodipine Benzoate interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
Read the full Resveratrol + Amlodipine Benzoate interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Amlodipine Benzoate interactionAmlodipine BesilateIstin
How Amlodipine Besilate interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
Read the full Resveratrol + Amlodipine Besilate interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Amlodipine Besilate interactionAmlodipine BesylateNorvasc
How Amlodipine Besylate interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
Read the full Resveratrol + Amlodipine Besylate interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Amlodipine Besylate interactionAmlodipine Besylate, BenazeprilLotrel
How Amlodipine Besylate, Benazepril interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
Read the full Resveratrol + Amlodipine Besylate, Benazepril interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Amlodipine Besylate, Benazepril interactionAmlodipine, CelecoxibConsensi
How Amlodipine, Celecoxib interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
Read the full Resveratrol + Amlodipine, Celecoxib interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Amlodipine, Celecoxib interactionAmoxicillin, Omeprazole Magnesium, RifabutinTalicia
How Amoxicillin, Omeprazole Magnesium, Rifabutin interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 2c19 (cyp2c19) Substrates, Cytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP2C19.
Read the full Resveratrol + Amoxicillin, Omeprazole Magnesium, Rifabutin interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Amoxicillin, Omeprazole Magnesium, Rifabutin interactionAmprenavirAgenerase
How Amprenavir interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
Read the full Resveratrol + Amprenavir interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Amprenavir interactionAnacaulase-bcdbNexoBrid
How Anacaulase-bcdb interacts with Mega-D3 — through 1 ingredient. Tap an ingredient for the detail:
ResveratrolAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Resveratrol may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Resveratrol + Anacaulase-bcdb interactionAnagrelideAgrylin
How Anagrelide interacts with Mega-D3 — through 1 ingredient. Tap an ingredient for the detail:
ResveratrolAnticoagulant/antiplatelet Drugs, Cytochrome P450 1a2 (cyp1a2) Substrates Moderate
Interaction Summary
Resveratrol may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Resveratrol + Anagrelide interactionAnisindioneMiradon
How Anisindione interacts with Mega-D3 — through 1 ingredient. Tap an ingredient for the detail:
ResveratrolAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Resveratrol may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Resveratrol + Anisindione interactionAntithrombin IiiThrombate III
How Antithrombin Iii interacts with Mega-D3 — through 1 ingredient. Tap an ingredient for the detail:
ResveratrolAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Resveratrol may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Resveratrol + Antithrombin Iii interactionApalutamideErleada
How Apalutamide interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
Read the full Resveratrol + Apalutamide interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Apalutamide interactionApixabanEliquis
How Apixaban interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolAnticoagulant/antiplatelet Drugs, Cytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Resveratrol may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Resveratrol + Apixaban interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Apixaban interactionApremilastOtezla
How Apremilast interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
Read the full Resveratrol + Apremilast interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Apremilast interactionAprepitantCinvanti, Emend
How Aprepitant interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
Read the full Resveratrol + Aprepitant interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Aprepitant interactionArgatrobanArgatroban
How Argatroban interacts with Mega-D3 — through 1 ingredient. Tap an ingredient for the detail:
ResveratrolAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Resveratrol may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Resveratrol + Argatroban interactionAripiprazoleAbilify, Abilify Maintena, Abilify Mycite
How Aripiprazole interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
Read the full Resveratrol + Aripiprazole interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Aripiprazole interactionAripiprazole LauroxilAristada, Aristada Initio Kit
How Aripiprazole Lauroxil interacts with Mega-D3 — through 2 ingredients. Tap an ingredient for the detail:
ResveratrolCytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
Read the full Resveratrol + Aripiprazole Lauroxil interactionVitamin D3Cytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D3 + Aripiprazole Lauroxil interactionEach ingredient & the kinds of drugs it affects
For each ingredient in Mega-D3 with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.
Vitamin D3
Aluminum
Vitamin D might increase aluminum absorption and toxicity, but this has only been reported in people with renal failure.
The protein that transports calcium across the intestinal wall can also bind and transport aluminum. This protein is stimulated by vitamin D, which may therefore increase aluminum absorption. This mechanism may contribute to increased aluminum levels and toxicity in people with renal failure, when they take vitamin D and aluminum-containing phosphate binders chronically.
Atorvastatin (Lipitor)
Vitamin D might reduce absorption of atorvastatin.
A small, low-quality clinical study shows that taking vitamin D reduces levels of atorvastatin and its active metabolites by up to 55%. However, while atorvastatin levels decreased, total cholesterol, low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol levels did not substantially change. Atorvastatin is metabolized in the gut by CYP3A4 enzymes, and researchers theorized that vitamin D might induce CYP3A4, causing reduced levels of atorvastatin. However, this proposed mechanism was not specifically studied.
Calcipotriene (Dovonex)
Taking calcipotriene with vitamin D increases 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 vitamin D supplements might increase the risk of hypercalcemia.
Digoxin (Lanoxin)
Theoretically, hypercalcemia induced by high-dose vitamin D can increase the risk of arrhythmia from digoxin.
High doses of vitamin D can cause hypercalcemia. Hypercalcemia increases the risk of fatal cardiac arrhythmias with digoxin. Avoid vitamin D doses above the tolerable upper intake level (4000 IU daily for adults) and monitor serum calcium levels in people taking vitamin D and digoxin concurrently.
Diltiazem (Cardizem, Others)
Theoretically, hypercalcemia induced by high-dose vitamin D can reduce the therapeutic effects of diltiazem for arrhythmia.
High doses of vitamin D can cause hypercalcemia. Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation. Theoretically this could also occur with diltiazem. Avoid vitamin D doses above the tolerable upper intake level (4000 IU daily for adults) and monitor serum calcium levels in people taking vitamin D and diltiazem concurrently.
Thiazide Diuretics
Theoretically, taking thiazide diuretics and high-dose vitamin D can increase the risk of hypercalcemia.
Thiazide diuretics decrease urinary calcium excretion, which could lead to hypercalcemia if vitamin D supplements are taken concurrently. This has been reported in people being treated with vitamin D for hypoparathyroidism, and also in elderly people with normal parathyroid function who were taking a thiazide, vitamin D, and calcium-containing antacids daily.
Verapamil (Calan, Others)
Hypercalcemia induced by high-dose vitamin D can reduce the therapeutic effects of verapamil for arrhythmia.
Hypercalcemia due to high doses of vitamin D can reduce the effectiveness of verapamil in atrial fibrillation. Avoid vitamin D doses above the tolerable upper intake level (4000 IU daily for adults) and monitor serum calcium levels in people taking vitamin D and verapamil concurrently.
Cytochrome P450 3A4 (Cyp3A4) Substrates
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
There is some concern that vitamin D might induce CYP3A4. In vitro research suggests that vitamin D induces CYP3A4 transcription. Additionally, observational research has found that increased UV light exposure and serum vitamin D levels are associated with decreased serum levels of CYP3A4 substrates such as tacrolimus and sirolimus, while no association between UV light exposure or vitamin D levels and levels of mycophenolic acid, a non-CYP3A4 substrate, was found. A small, low-quality clinical study shows that taking vitamin D reduces levels of the CYP3A4 substrate atorvastatin and its active metabolites by up to 55%; however, the clinical effects of atorvastatin were not reduced. While researchers theorized that vitamin D might induce CYP3A4, this proposed mechanism was not specifically studied.
Brand information
Manufacturer and brand details for Mega-D3, from the product label.
Schiff
See all Schiff products- Name
- Schiff Nutrition Group, Inc.
- City
- Salt Lake City
- State
- UT
- ZipCode
- 84104
- Phone Number
- 1-800-526-6251
- Web Address
- www.schiffvitamins.com
Mega-D3 by Schiff: Common Questions
Does Mega-D3 by Schiff interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Is this safe to take during pregnancy or while breastfeeding?
What's resveratrol, and why is it in here?
Will this upset my stomach?
Can I take this with my blood pressure or heart medication?
Does this product have fillers?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if Mega-D3 is safe with your meds?
Our pharmacists answer your medication & supplement questions — free.
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.
The Full Monographs Behind Mega-D3’s Ingredients
Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.
Vitamin D
Interacts with 715 drugsVitamin D is a fat-soluble vitamin that helps your body absorb calcium and is important for healthy bones, muscles, and immune function. Many people, especially those with low sun exposure,...
Read the full Vitamin D monograph → Herb & supplement monographResveratrol
Interacts with 822 drugsResveratrol is a plant compound found in red grapes, berries, and peanuts that is popular for heart health, anti-aging, and antioxidant support. While lab and animal studies are promising, s...
Read the full Resveratrol monograph →Sources & How We Checked
Mega-D3'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.
- NIH Dietary Supplement Label Database (DSLD) — The official product label on file for this supplement.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference behind the ingredient interaction data.
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 50 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 D 26 references
- McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
- Tatro DS, ed. Drug Interactions Facts. Facts and Comparisons Inc., St. Louis, MO. 1999.
- Koutkia P, Chen TC, Holick MF. Vitamin D intoxication associated with an over-the-counter supplement. N Engl J Med 2001;345:66-7. PubMed
- Bar-Or D, Yoel G. Calcium and calciferol antagonize effect of verapamil in atrial fibrillation. Br Med J 1981;282:1585-6.
- Demontis R, Leflon A, Fournier A, et al. 1 alpha(OH) vitamin D3 increases plasma aluminum in hemodialyzed patients taking AI(OH)3. Clin Nephrol 1986;26:146-9.
- Crowe M, Wollner L, Griffiths RA. Hypercalcemia following vitamin D and thiazide therapy in the elderly. Practitioner 1984;228:312-3.
- Parfitt AM. Thiazide-induced hypercalcemia in vitamin D-treated hypoparathyroidism. Ann Intern Med 1972;77:557-63. PubMed
- Thiazide diuretics and the risk of osteoporosis. Pharmacist's Letter/Prescriber's Letter 2003;19(11):191105.
- Moon J. The role of vitamin D in toxic metal absorption. J Am Coll Nutr 1994;13:559-64.
- Demontis R, Reissi D, Noel C, et al. Indirect clinical evidence that 1alphaOH vitamin D<SUB>3</SUB> increases the intestinal absorption of aluminum. Clin Nephrol 1989;31:123-7.
- Adler AJ, Berlyne GM. Duodenal aluminum absorption in the rat: effect of vitamin D. Am J Physiol 1985;249:G209-13. PubMed
- Schwartz JB. Effects of vitamin D supplementation in atorvastatin-treated patients: A new drug interaction with an unexpected consequence. Clin Pharmacol Ther 2009;85:198-203. PubMed
- Dietary reference intakes for calcium and vitamin D. Institute of Medicine, November 30, 2010. Available at: http://www.iom.edu/~/media/Files/Report%20Files/2010/Dietary-Reference-Intakes-for-Calcium-and-Vitamin-D/Vitamin%20D%20and%20Calcium%202010%20Repo
- Cox KA, Dunn MA. Aluminum toxicity alters the regulation of calbindin-D28k protein and mRNA expression in chick intestine. J Nutr 2001;131:2007-13. PubMed
- Escribano, J., Balaguer, A., Pagone, F., Feliu, A., and Roque, I. Figuls. Pharmacological interventions for preventing complications in idiopathic hypercalciuria. Cochrane.Database.Syst.Rev. 2009;(1):CD004754. PubMed
- Carlton, S., Clopton, D., and Cappuzzo, K. A. Vitamin D deficiency: appropriate replenishment therapies and the effects of vitamin D toxicity. Consult Pharm 2010;25(3):171-177. PubMed
- Wang, H., Xia, N., Yang, Y., and Peng, D. Q. Influence of vitamin D supplementation on plasma lipid profiles: a meta-analysis of randomized controlled trials. Lipids Health Dis. 2012;11:42. PubMed
- Turner AN, Carr Reese P, Fields KS, Anderson J, Ervin M, Davis JA, Fichorova RN, Roberts MW, Klebanoff MA, Jackson RD. A blinded, randomized controlled trial of high-dose vitamin D supplementation to reduce recurrence of bacterial vaginosis. Am J Obstet G PubMed
- Weiner M, Epstein FH. Signs and symptoms of electrolyte disorders. Yale J Biol Med. 1970;43(2):76-109.
- Lappe J, Watson P, Travers-Gustafson D, Recker R, Garland C, Gorham E, Baggerly K, McDonnell SL. Effect of Vitamin D and Calcium Supplementation on Cancer Incidence in Older Women: A Randomized Clinical Trial. JAMA. 2017 Mar 28;317(12):1234-1243. PubMed
- Roth DE, Leung M, Mesfin E, Qamar H, Watterworth J, Papp E. Vitamin D supplementation during pregnancy: state of the evidence from a systematic review of randomised trials. BMJ. 2017;359:j5237. PubMed
- Murai IH, Fernandes AL, Sales LP, et al. Effect of a single high dose of vitamin D3 on hospital length of stay in patients with moderate to severe COVID-19: A randomized clinical trial. JAMA. 2021.
- Wang Z, Schuetz EG, Xu Y, Thummel KE. Interplay between vitamin D and the drug metabolizing enzyme CYP3A4. J Steroid Biochem Mol Biol 2013;136:54-8. PubMed
- Doyle D, Browne U, Brickley A, Murphy D. Vitamin D-induced hypercalcaemia and acute kidney injury in sarcoidosis. BMJ Case Rep 2023;16(1):e250580. PubMed
- Williamson A, Martineau AR, Sheikh A, Jolliffe D, Griffiths CJ. Vitamin D for the management of asthma. Cochrane Database Syst Rev 2023;2(2):CD011511. PubMed
- Kinesya E, Santoso D, Gde Arya N, et al. Vitamin D as adjuvant therapy for diabetic foot ulcers: Systematic review and meta-analysis approach. Clin Nutr ESPEN 2023;54:137-143. PubMed
Resveratrol 24 references
- Soleas GJ, Diamandis EP, Goldberg DM. Resveratrol: a molecule whose time has come? And gone? Clin Biochem 1997;30:91-113.
- Pace-Asciak CR, Rounova O, Hahn SE, et al. Wines and grape juices as modulators of platelet aggregation in healthy human subjects. Clin Chim Acta 1996;246:163-82. PubMed
- Bertelli AA, Giovannini L, Bernini W, et al. Antiplatelet activity of cis-resveratrol. Drugs Exp Clin Res 1996;22:61-3.
- Pace-Asciak CR, Hahn S, Diamandis EP, et al. The red wine phenolics trans-resveratrol and quercetin block human platelet aggregation and eicosanoid synthesis: implications for protection against coronary heart disease. Clin Chim Acta 1995;235:207-19.
- Bertelli A, Bertelli AA, Gozzini A, Giovannini L. Plasma and tissue resveratrol concentrations and pharmacological activity. Drugs Exp Clin Res 1998;24:133-8.
- Bertelli AA, Giovannini L, Giannessi D, et al. Antiplatelet activity of synthetic and natural resveratrol in red wine. Int J Tissue React 1995;17:1-3.
- Piver B, Berthou F, Dreano Y, Lucas D. Inhibition of CYP3A, CYP1A and CYP2E1 activities by resveratrol and other non volatile red wine components. Toxicol Lett 2001;125:83-91. PubMed
- Chang, T. K., Chen, J., and Lee, W. B. Differential inhibition and inactivation of human CYP1 enzymes by trans-resveratrol: evidence for mechanism-based inactivation of CYP1A2. J.Pharmacol.Exp.Ther. 2001;299(3):874-882.
- Dobrydneva, Y., Williams, R. L., and Blackmore, P. F. trans-Resveratrol inhibits calcium influx in thrombin-stimulated human platelets. Br.J.Pharmacol. 1999;128(1):149-157.
- Kirk, R. I., Deitch, J. A., Wu, J. M., and Lerea, K. M. Resveratrol decreases early signaling events in washed platelets but has little effect on platalet in whole food. Blood Cells Mol.Dis. 2000;26(2):144-150.
- Zbikowska, H. M. and Olas, B. Antioxidants with carcinostatic activity (resveratrol, vitamin E and selenium) in modulation of blood platelet adhesion. J Physiol Pharmacol. 2000;51(3):513-520.
- Olas, B., Wachowicz, B., Saluk-Juszczak, J., and Zielinski, T. Effect of resveratrol, a natural polyphenolic compound, on platelet activation induced by endotoxin or thrombin. Thromb.Res 8-15-2002;107(3-4):141-145. PubMed
- Yu, C., Shin, Y. G., Kosmeder, J. W., Pezzuto, J. M., and van Breemen, R. B. Liquid chromatography/tandem mass spectrometric determination of inhibition of human cytochrome P450 isozymes by resveratrol and resveratrol-3-sulfate. Rapid Commun.Mass Spectro PubMed
- Ma, Z. H. and Ma, Q. Y. Resveratrol: a medical drug for acute pancreatitis. World J Gastroenterol. 6-7-2005;11(21):3171-3174. PubMed
- la, Porte C., Voduc, N., Zhang, G., Seguin, I., Tardiff, D., Singhal, N., and Cameron, D. W. Steady-State pharmacokinetics and tolerability of trans-resveratrol 2000 mg twice daily with food, quercetin and alcohol (ethanol) in healthy human subjects. Cli PubMed
- Brown, V. A., Patel, K. R., Viskaduraki, M., Crowell, J. A., Perloff, M., Booth, T. D., Vasilinin, G., Sen, A., Schinas, A. M., Piccirilli, G., Brown, K., Steward, W. P., Gescher, A. J., and Brenner, D. E. Repeat dose study of the cancer chemopreventive
- Pendurthi, U. R., Williams, J. T., and Rao, L. V. Resveratrol, a polyphenolic compound found in wine, inhibits tissue factor expression in vascular cells : A possible mechanism for the cardiovascular benefits associated with moderate consumption of wine. PubMed
- Chachay VS, Macdonald GA, Martin JH, Whitehead JP, O'Moore-Sullivan TM, Lee P, Franklin M, Klein K, Taylor PJ, Ferguson M, Coombes JS, Thomas GP, Cowin GJ, Kirkpatrick CM, Prins JB, Hickman IJ. Resveratrol does not benefit patients with nonalcoholic fatty
- Bedada SK, Neerati P. Resveratrol Pretreatment Affects CYP2E1 Activity of Chlorzoxazone in Healthy Human Volunteers. Phytother Res. 2016;30(3):463-8. PubMed
- Lin CT, Sun XY, Lin AX. Supplementation with high-dose trans-resveratrol improves ultrafiltration in peritoneal dialysis patients: a prospective, randomized, double-blind study. Ren Fail. 2016;38(2):214-21. PubMed
- Li Q, Yang G, Xu H, Tang S, Lee WY. Effects of resveratrol supplementation on bone quality: a systematic review and meta-analysis of randomized controlled trials. BMC Complement Med Ther 2021;21(1):214. PubMed
- McCreary MR, Schnell PM, Rhoda DA. Randomized double-blind placebo-controlled proof-of-concept trial of resveratrol for outpatient treatment of mild coronavirus disease (COVID-19). Sci Rep 2022;12(1):10978. PubMed
- Abdelhaleem IA, Brakat AM, Adayel HM, Asla MM, Rizk MA, Aboalfetoh AY. The effects of resveratrol on glycemic control and cardiometabolic parameters in patients with T2DM: A systematic review and meta-analysis. Med Clin (Barc) 2022;158(12):576-585. PubMed
- Badaoui A. Allergic contact dermatitis to resveratrol and Scutellaria baicalensis root extract in a cosmetic product. Contact Dermatitis 2022.
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