Vitamin D3 25 mcg (1000 IU) Ingredients & Drug Interactions
What is this page for?
First and foremost: checking Vitamin D3 25 mcg (1000 IU) 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
Vitamin D3 25 mcg (1000 IU) is a dietary supplement by Natural Factors 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, 885 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Vitamin D3, organic Flaxseed Oil. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against Vitamin D3 25 mcg (1000 IU) by Natural Factors
Ask about any prescription or over-the-counter medication and we check it for interactions with Vitamin D3 25 mcg (1000 IU) by Natural Factors — 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
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HelloPharmacist Scorecard of Vitamin D3 25 mcg (1000 IU) by Natural Factors
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
Full disclosure
This product has 2 active ingredients: vitamin D3 (cholecalciferol) and organic flaxseed oil. Vitamin D3 helps your body absorb calcium and maintain bone health; it's also used to treat bone diseases like rickets and hypoparathyroidism.
Flaxseed oil provides alpha-linolenic acid (a plant-based omega-3 fatty acid) and is included here to support general wellness. The softgel capsule is an inactive ingredient—the shell that holds the contents.
Does it work?
Strong evidence
Vitamin D3 is effective for specific medical conditions: familial hypophosphatemia, osteomalacia (soft bones), renal osteodystrophy, rickets, and hypoparathyroidism. If you're taking this product for one of those diagnoses, the evidence supports its use under medical supervision.
Flaxseed oil is a different story. The data shows it is possibly ineffective for obesity, rheumatoid arthritis, bipolar disorder, and high cholesterol.
If you're hoping flaxseed oil will lower cholesterol or help with any of those conditions, the evidence doesn't back that up.
How safe is it?
Well-documented data
Vitamin D3 is generally well tolerated at recommended doses like the 1000 IU in this product. Very high doses over time can cause vitamin D toxicity (hypercalcemia), with rare serious effects including bone loss in adults and slowed growth in children.
Flaxseed oil is generally well tolerated, but quality and dose vary by product—check with your doctor before use, especially at higher amounts. Rare serious allergic reactions to flaxseed oil (like anaphylaxis) have been reported.
A small number of people have reported changes in bowel habits, dry mouth, and indigestion at typical doses; very high doses (30 grams or more daily) are linked to loose stools and diarrhea. For both ingredients during pregnancy and breastfeeding, there isn't enough data to know either way—talk with your doctor or pharmacist for personalized advice before taking this product if you're pregnant or nursing.
Meds to double-check
Moderate interaction found
Before taking this product, double-check with your pharmacist if you take thiazide diuretics (water pills), digoxin, verapamil, diltiazem, or atorvastatin—all Moderate concerns with vitamin D3. Also flag blood thinners and antiplatelet drugs (Moderate, from flaxseed oil) and ezetimibe or other CYP3A4-processed medications.
These aren't automatic deal-breakers, but your pharmacist needs to know.
The bottom line
Scorecard at a glanceFully disclosed formula with clinical evidence supporting its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.
This product is appropriate for people diagnosed with vitamin D-deficiency bone diseases (rickets, hypoparathyroidism, osteomalacia) under medical supervision—that's where the evidence is strongest. If you take heart medications, blood thinners, cholesterol drugs, or medications for atrial fibrillation, check this product with your pharmacist first.
The flaxseed oil here isn't proven to treat obesity, arthritis, or high cholesterol. Talk to your pharmacist before starting, especially if you're pregnant, nursing, or taking other medications.
Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI
Assessment coverage: 2 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated May 22, 2020.
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 Vitamin D3 25 mcg (1000 IU), straight from the product label.
| Brand | Natural Factors |
|---|---|
| Barcode (UPC) | 068958010540 |
| Net contents | 180 Softgel(s) |
| Market status | On market |
| Date entered into DSLD | May 22, 2020 |
| DSLD ID | 220569 |
| Product type | Botanical With Nutrients |
| Supplement form | Softgel Capsule |
| Dietary claims / uses | Nutrient, All Other, Structure/Function |
| Intended target group(s) | Adult (18 - 50 Years), Gluten Free, Dairy Free, Sugar Free |
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.
Supplement Facts
The label details for Vitamin D3 25 mcg (1000 IU) by Natural Factors, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| Vitamin D3 | 25 mcg | 125% |
| organic Flaxseed Oil | 200 mg | -- |
Other ingredients: Softgel
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.
FDA Statement of Identity
Dietary Supplement
Seals/Symbols
isura Non-GMO - Mass Spec Documentation Lab tested
Purity & Potency Guaranteed
Suggested/Recommended/Usage/Directions
Suggested Usage: 1 softgel per day or as directed by a health professional.
Precautions
Cautions: As with any supplement, consult your health professional before use if you are pregnant, breastfeeding, or trying to conceive, or if you are taking medication, have a medical condition, or anticipate a surgery.
Keep out of the reach of children.
Sealed for your protection. Do not use if seal is broken.
Formula
Vitamin D3 is essential for strong bones and teeth as it increases the body's absorption of calcium from food. Its role in regulating calcium levels also helps regulate the immune system and maintain healthy nerves and muscles. Vitamin D3 is carefully blended with organic flaxseed oil in an easy-to-swallow softgel.
Formulation
Manufactured by Natural Factors to ensure safety and potency in accordance with Good Manufacturing Practices (GMP) of the FDA and Health Canada.
Contains no artificial colors, preservatives, or sweeteners; no dairy, starch, sugar, wheat, gluten, yeast, soy, corn, egg, fish, shellfish, salt, tree nuts, or GMOs.
Supports healthy bones
Storage
For freshness, store in a cool, dry place.
FDA Disclaimer Statement
This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
General Statements
Product of Canada Recyclable container and label.
Brand IP Statement(s)
Isura is a trademark of ISURA.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
Vitamin D3 25 mcg (1000 IU) by Natural Factors 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 Vitamin D3 25 mcg (1000 IU) by Natural Factors
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 & interactionsOrganic Flaxseed Oil
Interacts with293 drugs
Flaxseed oil is a plant-based source of the omega-3 fatty acid ALA, which the body can partly convert to the omega-3s found in fish oil. It may help s...
Organic Flaxseed Oil monograph & interactionsOther (inactive) ingredients: Softgel. These complete the product’s ingredient list but are not active constituents.
Vitamin D3 25 mcg (1000 IU) by Natural Factors Drug Interactions
HelloPharmacist Interaction Report
Natural Factors Vitamin D3 25 mcg (1000 IU) contains two active ingredients, and one of them—vitamin D3—has documented interactions with multiple medication types.
The most serious concern is with thiazide diuretics (water pills), calcium channel blockers (verapamil and diltiazem), and digoxin, all rated Moderate: high-dose vitamin D can raise blood calcium levels (hypercalcemia), which reduces how well these heart and blood pressure drugs work and may trigger dangerous heart rhythms with digoxin. At the dose in this product (1000 IU daily), you're well below the tolerable upper limit (4000 IU for adults), so this risk is mainly theoretical—but the interaction matters if you take extra vitamin D from other sources.
Read the full breakdown — every affected drug type, severity by severity
Vitamin D3 also has Moderate interactions with atorvastatin (a cholesterol drug), where vitamin D may reduce its absorption, and with calcipotriene (a psoriasis medication that contains a vitamin D-like compound), which together raise hypercalcemia risk. A Minor interaction exists with a broad class of drugs processed by the CYP3A4 enzyme pathway; vitamin D might reduce their effectiveness, but clinical evidence is limited.
The flaxseed oil in this product has Moderate interactions with blood thinners and antiplatelet drugs (increased bleeding risk) and with ezetimibe (a cholesterol drug), where the two together can block absorption of flaxseed oil's active compound. Flaxseed oil may also lower blood pressure, which could add to blood pressure medications.
Before you start, check your exact medications with the search tool on this page—especially if you take heart drugs, cholesterol medications, blood thinners, or psoriasis treatments.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against Vitamin D3 25 mcg (1000 IU)?
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 Vitamin D3 25 mcg (1000 IU) interact with 885 drugs. Click any drug to see the details.
2 of the 2 ingredients in Vitamin D3 25 mcg (1000 IU) interact with drugs. Each result below shows which ingredient is responsible. Vitamin D3 organic Flaxseed Oil
AbciximabReoPro
How Abciximab interacts with Vitamin D3 25 mcg (1000 IU) — through 1 ingredient. Tap an ingredient for the detail:
Organic Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Organic Flaxseed Oil + Abciximab interactionAbrocitinibCibinqo
How Abrocitinib interacts with Vitamin D3 25 mcg (1000 IU) — through 1 ingredient. Tap an ingredient for the detail:
Organic Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Organic Flaxseed Oil + Abrocitinib interactionAcebutololRhotral, Sectral
How Acebutolol interacts with Vitamin D3 25 mcg (1000 IU) — through 1 ingredient. Tap an ingredient for the detail:
Organic Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Organic Flaxseed Oil + Acebutolol interactionAcenocoumarolSintrom
How Acenocoumarol interacts with Vitamin D3 25 mcg (1000 IU) — through 1 ingredient. Tap an ingredient for the detail:
Organic Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Organic Flaxseed Oil + Acenocoumarol interactionAcetaminophen, AspirinGemnisyn
How Acetaminophen, Aspirin interacts with Vitamin D3 25 mcg (1000 IU) — through 1 ingredient. Tap an ingredient for the detail:
Organic Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Organic Flaxseed Oil + Acetaminophen, Aspirin interactionAcetaminophen, Aspirin, CaffeineExcedrin, Excedrin Extra Strength, Excedrin Migraine
How Acetaminophen, Aspirin, Caffeine interacts with Vitamin D3 25 mcg (1000 IU) — through 2 ingredients. Tap an ingredient for the detail:
Organic Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Organic Flaxseed Oil + Acetaminophen, Aspirin, Caffeine 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 + Acetaminophen, Aspirin, Caffeine interactionAcetaminophen, IbuprofenCombogesic
How Acetaminophen, Ibuprofen interacts with Vitamin D3 25 mcg (1000 IU) — through 1 ingredient. Tap an ingredient for the detail:
Organic Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Organic Flaxseed Oil + Acetaminophen, Ibuprofen interactionAcetazolamideAk-Zol, Diamox
How Acetazolamide interacts with Vitamin D3 25 mcg (1000 IU) — through 1 ingredient. Tap an ingredient for the detail:
Organic Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Organic Flaxseed Oil + Acetazolamide interactionAcetylsalicylic AcidEntrophen
How Acetylsalicylic Acid interacts with Vitamin D3 25 mcg (1000 IU) — through 1 ingredient. Tap an ingredient for the detail:
Organic Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Organic Flaxseed Oil + Acetylsalicylic Acid interactionAlginic Acid, Aluminum HydroxideRafton
How Alginic Acid, Aluminum Hydroxide interacts with Vitamin D3 25 mcg (1000 IU) — 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 + Alginic Acid, Aluminum Hydroxide interactionAliskirenTekturna
How Aliskiren interacts with Vitamin D3 25 mcg (1000 IU) — through 2 ingredients. Tap an ingredient for the detail:
Organic Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Organic Flaxseed Oil + Aliskiren 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 + Aliskiren interactionAlteplase, TpaActilyse, Activase
How Alteplase, Tpa interacts with Vitamin D3 25 mcg (1000 IU) — through 1 ingredient. Tap an ingredient for the detail:
Organic Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Organic Flaxseed Oil + Alteplase, Tpa interactionAluminum Acetate, Benzethonium ChlorideBuro-Sol Otic Solution
How Aluminum Acetate, Benzethonium Chloride interacts with Vitamin D3 25 mcg (1000 IU) — 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 Acetate, Benzethonium Chloride interactionAluminum ChlorideAluminum Chloride, Anhydrol Forte, Driclor, Drysol
How Aluminum Chloride interacts with Vitamin D3 25 mcg (1000 IU) — 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 Chloride interactionAluminum HydroxideAlu-Cap, Amphojel, Gaviscon
How Aluminum Hydroxide interacts with Vitamin D3 25 mcg (1000 IU) — 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 interactionAluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium HydroxideAscriptin Codeine #2
How Aluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium Hydroxide interacts with Vitamin D3 25 mcg (1000 IU) — through 2 ingredients. 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, Aspirin, Codeine Phosphate, Magnesium Hydroxide interactionOrganic Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Organic Flaxseed Oil + Aluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium Hydroxide interactionAluminum Hydroxide, Aspirin, Magnesium HydroxideAscriptin
How Aluminum Hydroxide, Aspirin, Magnesium Hydroxide interacts with Vitamin D3 25 mcg (1000 IU) — through 2 ingredients. Tap an ingredient for the detail:
Organic Flaxseed OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Read the full Organic Flaxseed Oil + Aluminum Hydroxide, Aspirin, Magnesium Hydroxide interactionVitamin 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, Aspirin, Magnesium Hydroxide interactionAluminum Hydroxide, Magnesium Hydroxide (otc Drug)Maalox, Mucogel
How Aluminum Hydroxide, Magnesium Hydroxide (otc Drug) interacts with Vitamin D3 25 mcg (1000 IU) — 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 Vitamin D3 25 mcg (1000 IU) — 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 Vitamin D3 25 mcg (1000 IU) — 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 Vitamin D3 25 mcg (1000 IU) — 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 Vitamin D3 25 mcg (1000 IU) — 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 Vitamin D3 25 mcg (1000 IU) — through 2 ingredients. Tap an ingredient for the detail:
Organic Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Organic Flaxseed Oil + 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 interactionAmilorideAmilamont, Midamor
How Amiloride interacts with Vitamin D3 25 mcg (1000 IU) — through 1 ingredient. Tap an ingredient for the detail:
Organic Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Organic Flaxseed Oil + Amiloride interactionAmiloride, HydrochlorothiazideAmil-Co, Amilzide, Moduret 25, Moduretic
How Amiloride, Hydrochlorothiazide interacts with Vitamin D3 25 mcg (1000 IU) — through 2 ingredients. Tap an ingredient for the detail:
Organic Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Organic Flaxseed Oil + Amiloride, Hydrochlorothiazide interactionVitamin 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 interactionAmlodipineNorliqva
How Amlodipine interacts with Vitamin D3 25 mcg (1000 IU) — through 2 ingredients. Tap an ingredient for the detail:
Organic Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Organic Flaxseed Oil + 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 Vitamin D3 25 mcg (1000 IU) — through 2 ingredients. Tap an ingredient for the detail:
Organic Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Organic Flaxseed Oil + 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 Vitamin D3 25 mcg (1000 IU) — through 2 ingredients. Tap an ingredient for the detail:
Organic Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Organic Flaxseed Oil + 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 Vitamin D3 25 mcg (1000 IU) — through 2 ingredients. Tap an ingredient for the detail:
Organic Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Organic Flaxseed Oil + 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 Vitamin D3 25 mcg (1000 IU) — through 2 ingredients. Tap an ingredient for the detail:
Organic Flaxseed OilAntihypertensive Drugs Moderate
Interaction Summary
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Read the full Organic Flaxseed Oil + 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 interactionEach ingredient & the kinds of drugs it affects
For each ingredient in Vitamin D3 25 mcg (1000 IU) with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.
Vitamin 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.
organic Flaxseed Oil
Anticoagulant/Antiplatelet Drugs
Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Small clinical studies show that consuming flaxseed oil might decrease platelet aggregation and increase bleeding time.
Antihypertensive Drugs
Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.
Some clinical evidence suggests that long-term consumption of flaxseed oil can modestly lower systolic and diastolic blood pressure, while other clinical research shows no effect.
Ezetimibe (Zetia)
Concomitant use of flaxseed oil and ezetimibe reduces the absorption of alpha-linolenic acid from flaxseed oil.
In one clinical study, concomitant consumption of ezetimibe 10 mg daily with flaxseed oil 2 grams providing 1 gram of alpha-linolenic acid daily blocked the absorption of alpha-linolenic acid, resulting in an overall reduction in alpha-linolenic plasma levels from baseline.
Brand information
Manufacturer and brand details for Vitamin D3 25 mcg (1000 IU), from the product label.
Vitamin D3 25 mcg (1000 IU) by Natural Factors: Common Questions
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Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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The Full Monographs Behind Vitamin D3 25 mcg (1000 IU)’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 monographFlaxseed Oil
Interacts with 293 drugsFlaxseed oil is a plant-based source of the omega-3 fatty acid ALA, which the body can partly convert to the omega-3s found in fish oil. It may help support heart health and provide healthy...
Read the full Flaxseed Oil monograph →Sources & How We Checked
Vitamin D3 25 mcg (1000 IU)'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 47 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
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- 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
Flaxseed Oil 21 references
- Kolonel LN, Nomura AM, Cooney RV. Dietary fat and prostate cancer: current status. J Natl Cancer Inst 1999;91:414-28. PubMed
- Ramon JM, Bou R, Romea S, et al. Dietary fat intake and prostate cancer risk: a case-control study in Spain. Cancer Causes Control 2000;11:679-85. PubMed
- Nordstrom DC, Honkanen VE, Nasu Y, et al. Alpha-linolenic acid in the treatment of rheumatoid arthritis. A double-blind, placebo-controlled and randomized study: flaxseed vs. safflower seed. Rheumatol Int 1995;14:231-4. PubMed
- De Stefani E, Deneo-Pellegrini H, Boffetta P, et al. Alpha-linolenic acid and risk of prostate cancer: a case-control study in Uruguay. Cancer Epidemiol Biomarkers Prev 2000;9:335-8.
- Giovannucci E, Rimm EB, Colditz GA, et al. A prospective study of dietary fat and risk of prostate cancer. J Natl Cancer Inst 1993;85:1571-9. PubMed
- Bloedon LT, Szapary PO. Flaxseed and cardiovascular risk. Nutr Rev 2004;62:18-27. DOI
- Laaksonen DE, Laukkanen JA, Niskanen L, et al. Serum linoleic and total polyunsaturated fatty acids in relation to prostate and other cancers: a population-based cohort study. Int J Cancer 2004;111:444-50.. PubMed
- Brouwer IA, Katan MB, Zock PL. Dietary alpha-linolenic acid is associated with reduced risk of fatal coronary heart disease, but increased prostate cancer risk: a meta-analysis. J Nutr 2004;134:919-22.
- Paschos GK, Magkos F, Panagiotakos DB, et al. Dietary supplementation with flaxseed oil lowers blood pressure in dyslipidaemic patients. Eur J Clin Nutr 2007;61:1201-6. PubMed
- Harper CR, Edwards MC, Jacobson TA. Flaxseed oil supplementation does not affect plasma lipoprotein concentration or particle size in human subjects. J Nutr 2006;136:2844-8. PubMed
- University of Montreal. Pregnant Women Consuming Flaxseed Oil Have High Risk Of Premature Birth.ScienceDaily, October 29, 2008. Available at: www.sciencedaily.com/releases/2008/10/081027140817.htm (Accessed May 14, 2009).
- Allman, M. A., Pena, M. M., and Pang, D. Supplementation with flaxseed oil versus sunflowerseed oil in healthy young men consuming a low fat diet: effects on platelet composition and function. Eur.J Clin.Nutr. 1995;49(3):169-178.
- Ursoniu S, Sahebkar A, Andrica F, Serban C, Banach M; Lipid and Blood Pressure Meta-analysis Collaboration Group. Effects of flaxseed supplements on blood pressure: a systematic review and meta-analysis of controlled clinical trial. Clin Nutr. 2016 Jun;3 PubMed
- Taghizadeh M, Jamilian M, Mazloomi M, Sanami M, Asemi Z. A randomized-controlled clinical trial investigating the effect of omega-3 fatty acids on vitamin E co-supplementation on markers of insulin metabolism and lipid profiles in gestational diabetes. J
- Blackwood DP, LaVallee RK, Al Busaidi A, Jassal DS, Pierce GN. A randomized trial of the effects of ezetimibe on the absorption of omega-3 fatty acids in cardiac disease patients: a pilot study. Clin Nutr ESPEN. 2015 Oct;10(5):e155-e159. PubMed
- Morshedzadeh N, Shahrokh S, Aghdaei HA, et al. Effects of flaxseed and flaxseed oil supplement on serum levels of inflammatory markers, metabolic parameters and severity of disease in patients with ulcerative colitis. Complement Ther Med. 2019;46:36-43. PubMed
- Downie LE, Hom MM, Berdy GJ, et al. An artificial tear containing flaxseed oil for treating dry eye disease: A randomized controlled trial. Ocul Surf. 2020;18(1):148-157. PubMed
- Saleh-Ghadimi S, Kheirouri S, Golmohammadi A, Moludi J, Jafari-Vayghan H, Alizadeh M. Effect of flaxseed oil supplementation on anthropometric and metabolic indices in patients with coronary artery disease: A double-blinded randomized controlled trial. J PubMed
- Jamilian M, Tabassi Z, Reiner Z, et al. The effects of n-3 fatty acids from flaxseed oil on genetic and metabolic profiles in patients with gestational diabetes mellitus: a randomised, double-blind, placebo-controlled trial. Br J Nutr. 2020;123(7):792-799
- Li L, Li H, Gao Y, Vafaei S, Zhang X, Yang M. Effect of flaxseed supplementation on blood pressure: a systematic review, and dose-response meta-analysis of randomized clinical trials. Food Funct 2023;14(2):675-690. PubMed
- Mahmudiono T, Jasim SA, Karim YS, et al. The effect of flaxseed oil consumption on blood pressure among patients with metabolic syndrome and related disorders: A systematic review and meta-analysis of randomized clinical trials. Phytother Res 2022;36(10):
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