K2 + D3 Ingredients & Drug Interactions
What is this page for?
First and foremost: checking K2 + 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
K2 + D3 is a dietary supplement by SR SportsResearch 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, 715 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Vitamin D, Vitamin K. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against K2 + D3 by SR SportsResearch
Ask about any prescription or over-the-counter medication and we check it for interactions with K2 + D3 by SR SportsResearch — 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 K2 + D3 by SR SportsResearch
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 contains 2 active ingredients: vitamin D and vitamin K (phylloquinone, also called K2). Vitamin D helps your body absorb calcium and plays a role in bone health, immune function, and calcium regulation.
Vitamin K is essential for blood clotting and is also involved in bone metabolism. The product is delivered in a veggie softgel capsule and includes organic virgin coconut oil, non-GMO rice bran wax, and olive oil as inactive ingredients.
Does it work?
Strong evidence
Vitamin D is effective for treating rickets, osteomalacia (soft bones), renal bone disease, hypoparathyroidism, and familial hypophosphatemia. Vitamin K is effective for treating clotting factor deficiencies and correcting bleeding disorders related to vitamin K deficiency.
The same ingredient is also effective for managing warfarin dosing. Vitamin K is possibly effective for osteoporosis, though the evidence is less robust.
How safe is it?
Well-documented data
Both ingredients are generally well tolerated at recommended doses. Vitamin D is safe at typical amounts, but very high doses taken over time can cause toxicity—symptoms include high calcium levels (hypercalcemia), weak bones, and in children, slowed growth.
Vitamin K taken by mouth rarely causes problems; mild stomach upset, nausea, diarrhea, or abdominal pain can occur in some people. Vitamin D is likely safe during pregnancy at recommended amounts and likely safe during breastfeeding, though you should use it only under your doctor's guidance.
Vitamin K is likely safe during both pregnancy and breastfeeding. Do not take high doses without checking with your doctor first.
Meds to double-check
Major interaction found
Before taking this product, double-check with your doctor or pharmacist if you take warfarin or any blood thinner—vitamin K directly opposes its effect. Also confirm if you're on thiazide diuretics, calcium channel blockers (verapamil or diltiazem), digoxin, atorvastatin, or calcipotriene.
If you take medications broken down by your liver's CYP3A4 enzyme, mention this product as well.
The bottom line
Scorecard at a glanceFully disclosed formula with clinical evidence supporting its stated purpose. Major medication interactions have been identified, and safety information is well characterized.
K2 + D3 is useful if you're looking to support bone health and calcium absorption through vitamin D, or if your diet is low in vitamin K. However, if you take warfarin, any blood pressure medication called a thiazide diuretic, a heart rhythm drug (verapamil, diltiazem, or digoxin), a statin like atorvastatin, or a psoriasis cream with calcipotriene, you need to discuss this product with your own doctor or pharmacist before starting.
The same goes if you take high-dose vitamin D or aluminum-based antacids and have kidney disease.
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 Jan 22, 2021.
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 K2 + D3, straight from the product label.
| Brand | SR SportsResearch |
|---|---|
| Net contents | 60 Veggie Softgel(s) |
| Market status | On market |
| Date entered into DSLD | Jan 22, 2021 |
| DSLD ID | 240403 |
| Product type | Vitamin |
| Supplement form | Softgel Capsule |
| Dietary claims / uses | Nutrient, All Other |
| Intended target group(s) | Vegan, Vegetarian, Adult (18 - 50 Years), Gluten 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 K2 + D3 by SR SportsResearch, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| Vitamin D | 125 mcg | 625% |
| Vitamin K | 100 mcg | 83% |
Other ingredients: organic virgin Coconut Oil, non-GMO Rice Bran Wax, Veggie Softgel Capsule, Olive Oil
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.
Formula
2-in-1 formula Made with coconut oil 100 mcg vitamin K2 as MK-7 125 mcg vitamin D3 (5000 IU)
Made with vegan D3 derived from lichen & vegan K2 derived from chickpeas
FDA Statement of Identity
Dietary Supplement
Seals/Symbols
Certified Vegan Vegan.org cGMP Compliant Good Manufacturing Practice 3rd Party Quality Tested Non GMO Project Verified nongmoproject.org
Formulation
Certified Vegan Vegan.org
Gluten free Non GMO
Precautions
Allergen Warning: Contains tree nuts (coconut).
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
K2 + D3 by SR SportsResearch 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 K2 + D3 by SR SportsResearch
These are the 2 active ingredients this product is made of. Select any to open its full monograph.
Serving size1 Liquid Veggie Softgel Dosage formSoftgel Capsule Servings per container60 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 D
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 D monograph & interactionsVitamin K
Interacts with2 drugs
Vitamin K is an essential nutrient your body needs for normal blood clotting and to support healthy bones. Most people get enough from food, but suppl...
Vitamin K monograph & interactionsOther (inactive) ingredients: Organic virgin Coconut Oil, Non-GMO Rice Bran Wax, Veggie Softgel Capsule, Olive Oil. These complete the product’s ingredient list but are not active constituents.
K2 + D3 by SR SportsResearch Drug Interactions
HelloPharmacist Interaction Report
K2 + D3 by SR SportsResearch contains two active ingredients—vitamin D and vitamin K—that interact with medications.
The most serious interaction is vitamin K with warfarin (Coumadin), a blood thinner. Vitamin K directly counteracts warfarin's effects, which can lead to loss of blood clot prevention and serious clotting risk.
Read the full breakdown — every affected drug type, severity by severity
Vitamin D carries several moderate-severity interactions. It can raise calcium levels (hypercalcemia) when combined with thiazide diuretics (water pills for blood pressure), calcium channel blockers like verapamil or diltiazem (used for heart rhythm problems), or digoxin (a heart medication)—all of which become less effective or riskier at high calcium levels.
Vitamin D may also reduce how well your body absorbs atorvastatin (Lipitor), a cholesterol drug. Additionally, taking vitamin D with calcipotriene (Dovonex), a vitamin D-like psoriasis cream, raises hypercalcemia risk further.
Aluminum-containing products (like some antacids) may be absorbed more readily if you're taking high-dose vitamin D, particularly if you have kidney problems.
Vitamin D may also affect how your liver processes certain medications by inducing a liver enzyme (CYP3A4); this is a minor interaction that could theoretically reduce levels of some drugs broken down this way.
Additionally, no interactions are documented in our data for the inactive ingredients (coconut oil, rice bran wax, olive oil, and the veggie capsule material). Altogether, these interactions span 716 individual medications.
Check your exact medications with the search tool on this page before starting.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against K2 + 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 K2 + D3 interact with 715 drugs. Click any drug to see the details.
2 of the 2 ingredients in K2 + D3 interact with drugs. Each result below shows which ingredient is responsible. Vitamin D Vitamin K
WarfarinWarfarin
How Warfarin interacts with K2 + D3 — through 2 ingredients. Tap an ingredient for the detail:
Vitamin KWarfarin (coumadin) Major
Interaction Summary
Vitamin K can antagonize and reverse the therapeutic effects of warfarin.
Read the full Vitamin K + Warfarin interactionVitamin DCytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D + Warfarin interactionWarfarin SodiumCoumadin, Panwarfin, Sofarin
How Warfarin Sodium interacts with K2 + D3 — through 2 ingredients. Tap an ingredient for the detail:
Vitamin KWarfarin (coumadin) Major
Interaction Summary
Vitamin K can antagonize and reverse the therapeutic effects of warfarin.
Read the full Vitamin K + Warfarin Sodium interactionVitamin DCytochrome P450 3a4 (cyp3a4) Substrates Minor
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D + Warfarin Sodium interactionAlginic Acid, Aluminum HydroxideRafton
How Alginic Acid, Aluminum Hydroxide interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DAluminum 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 D + Alginic Acid, Aluminum Hydroxide interactionAluminum Acetate, Benzethonium ChlorideBuro-Sol Otic Solution
How Aluminum Acetate, Benzethonium Chloride interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DAluminum 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 D + Aluminum Acetate, Benzethonium Chloride interactionAluminum ChlorideAluminum Chloride, Anhydrol Forte, Driclor, Drysol
How Aluminum Chloride interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DAluminum 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 D + Aluminum Chloride interactionAluminum HydroxideAlu-Cap, Amphojel, Gaviscon
How Aluminum Hydroxide interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DAluminum 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 D + Aluminum Hydroxide interactionAluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium HydroxideAscriptin Codeine #2
How Aluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium Hydroxide interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DAluminum 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 D + Aluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium Hydroxide interactionAluminum Hydroxide, Aspirin, Magnesium HydroxideAscriptin
How Aluminum Hydroxide, Aspirin, Magnesium Hydroxide interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DAluminum 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 D + Aluminum Hydroxide, Aspirin, Magnesium Hydroxide interactionAluminum Hydroxide, Magnesium Hydroxide (otc Drug)Maalox, Mucogel
How Aluminum Hydroxide, Magnesium Hydroxide (otc Drug) interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DAluminum 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 D + Aluminum Hydroxide, Magnesium Hydroxide (otc Drug) interactionAluminum Hydroxide, Magnesium Hydroxide, Simethicone (otc Drug)Mylanta
How Aluminum Hydroxide, Magnesium Hydroxide, Simethicone (otc Drug) interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DAluminum 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 D + Aluminum Hydroxide, Magnesium Hydroxide, Simethicone (otc Drug) interactionAluminum, CalciumDomeboro
How Aluminum, Calcium interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DAluminum 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 D + Aluminum, Calcium interactionAluminum, Magnesium (otc Drug)Almagel
How Aluminum, Magnesium (otc Drug) interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DAluminum 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 D + Aluminum, Magnesium (otc Drug) interactionAluminum, Magnesium Hydroxide (otc Drug)Wingel
How Aluminum, Magnesium Hydroxide (otc Drug) interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DAluminum 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 D + Aluminum, Magnesium Hydroxide (otc Drug) interactionAmiloride, HydrochlorothiazideAmil-Co, Amilzide, Moduret 25, Moduretic
How Amiloride, Hydrochlorothiazide interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DThiazide Diuretics Moderate
Interaction Summary
Theoretically, taking thiazide diuretics and high-dose vitamin D can increase the risk of hypercalcemia.
Read the full Vitamin D + Amiloride, Hydrochlorothiazide interactionAspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium HydroxideAscriptin Codeine #3
How Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DAluminum 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 D + Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide interactionAtenolol, ChlortalidoneAtenixCo, Tenoret 50, Totaretic
How Atenolol, Chlortalidone interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DThiazide Diuretics Moderate
Interaction Summary
Theoretically, taking thiazide diuretics and high-dose vitamin D can increase the risk of hypercalcemia.
Read the full Vitamin D + Atenolol, Chlortalidone interactionAtenolol, ChlorthalidoneTenoretic
How Atenolol, Chlorthalidone interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DThiazide Diuretics Moderate
Interaction Summary
Theoretically, taking thiazide diuretics and high-dose vitamin D can increase the risk of hypercalcemia.
Read the full Vitamin D + Atenolol, Chlorthalidone interactionAtorvastatinAtorvaliq
How Atorvastatin interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DCytochrome P450 3a4 (cyp3a4) Substrates, Atorvastatin (lipitor) Moderate
Interaction Summary
Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
Read the full Vitamin D + Atorvastatin interactionAtorvastatin CalciumLipitor
How Atorvastatin Calcium interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DAtorvastatin (lipitor), Cytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Vitamin D might reduce absorption of atorvastatin.
Read the full Vitamin D + Atorvastatin Calcium interactionAzilsartan, ChlorthalidoneEdarbyclor
How Azilsartan, Chlorthalidone interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DThiazide Diuretics Moderate
Interaction Summary
Theoretically, taking thiazide diuretics and high-dose vitamin D can increase the risk of hypercalcemia.
Read the full Vitamin D + Azilsartan, Chlorthalidone interactionBenazepril, HydrochlorothiazideLotensin HCT
How Benazepril, Hydrochlorothiazide interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DThiazide Diuretics Moderate
Interaction Summary
Theoretically, taking thiazide diuretics and high-dose vitamin D can increase the risk of hypercalcemia.
Read the full Vitamin D + Benazepril, Hydrochlorothiazide interactionBendroflumethiazideAprinox, Naturetin, Neo-NaClex
How Bendroflumethiazide interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DThiazide Diuretics Moderate
Interaction Summary
Theoretically, taking thiazide diuretics and high-dose vitamin D can increase the risk of hypercalcemia.
Read the full Vitamin D + Bendroflumethiazide interactionBendroflumethiazide, NadololCorzide
How Bendroflumethiazide, Nadolol interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DThiazide Diuretics Moderate
Interaction Summary
Theoretically, taking thiazide diuretics and high-dose vitamin D can increase the risk of hypercalcemia.
Read the full Vitamin D + Bendroflumethiazide, Nadolol interactionBendroflumethiazide, PotassiumCentyl K, Neo-NaClex-K
How Bendroflumethiazide, Potassium interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DThiazide Diuretics Moderate
Interaction Summary
Theoretically, taking thiazide diuretics and high-dose vitamin D can increase the risk of hypercalcemia.
Read the full Vitamin D + Bendroflumethiazide, Potassium interactionBendroflumethiazide, Rauwolfia SerpentinaRauzide
How Bendroflumethiazide, Rauwolfia Serpentina interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DThiazide Diuretics Moderate
Interaction Summary
Theoretically, taking thiazide diuretics and high-dose vitamin D can increase the risk of hypercalcemia.
Read the full Vitamin D + Bendroflumethiazide, Rauwolfia Serpentina interactionBenzthiazideExna
How Benzthiazide interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DThiazide Diuretics Moderate
Interaction Summary
Theoretically, taking thiazide diuretics and high-dose vitamin D can increase the risk of hypercalcemia.
Read the full Vitamin D + Benzthiazide interactionBetamethasone Dipropionate, CalcipotrieneEnstilar, Wynzora
How Betamethasone Dipropionate, Calcipotriene interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DCalcipotriene (dovonex) Moderate
Interaction Summary
Taking calcipotriene with vitamin D increases the risk for hypercalcemia.
Read the full Vitamin D + Betamethasone Dipropionate, Calcipotriene interactionBisoprolol, HydrochlorothiazideZiac
How Bisoprolol, Hydrochlorothiazide interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DThiazide Diuretics Moderate
Interaction Summary
Theoretically, taking thiazide diuretics and high-dose vitamin D can increase the risk of hypercalcemia.
Read the full Vitamin D + Bisoprolol, Hydrochlorothiazide interactionCalcipotrieneDovonex
How Calcipotriene interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DCalcipotriene (dovonex) Moderate
Interaction Summary
Taking calcipotriene with vitamin D increases the risk for hypercalcemia.
Read the full Vitamin D + Calcipotriene interactionCandesartan Cilexetil, HydrochlorothiazideAtacand HCT
How Candesartan Cilexetil, Hydrochlorothiazide interacts with K2 + D3 — through 1 ingredient. Tap an ingredient for the detail:
Vitamin DThiazide Diuretics Moderate
Interaction Summary
Theoretically, taking thiazide diuretics and high-dose vitamin D can increase the risk of hypercalcemia.
Read the full Vitamin D + Candesartan Cilexetil, Hydrochlorothiazide interactionEach ingredient & the kinds of drugs it affects
For each ingredient in K2 + D3 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 D
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.
Vitamin K
Warfarin (Coumadin)
Vitamin K can antagonize and reverse the therapeutic effects of warfarin.
Vitamin K antagonizes the effects of warfarin. Excessive vitamin K intake, either from supplements or from changes in the diet, can reduce the anticoagulant effect of warfarin.
Brand information
Manufacturer and brand details for K2 + D3, from the product label.
K2 + D3 by SR SportsResearch: Common Questions
Does K2 + D3 by SR SportsResearch interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Can I take this if I'm pregnant or breastfeeding?
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Does this really help with bones and blood clotting?
What's in the capsule besides the vitamins?
Is it safe to take this every day?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if K2 + 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 K2 + 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 monographVitamin K
Interacts with 2 drugsVitamin K is an essential nutrient your body needs for normal blood clotting and to support healthy bones. Most people get enough from food, but supplements are sometimes used for deficiency...
Read the full Vitamin K monograph →Sources & How We Checked
K2 + 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 37 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.
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