Synergy K Ingredients & Drug Interactions
What is this page for?
First and foremost: checking Synergy K 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
Synergy K is a dietary supplement by Pure Encapsulations with 4 active ingredients. Its ingredients are commonly taken for supporting normal blood clotting, bone health, heart and vascular health.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 K1. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against Synergy K by Pure Encapsulations
Ask about any prescription or over-the-counter medication and we check it for interactions with Synergy K by Pure Encapsulations — 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 Synergy K by Pure Encapsulations
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
Synergy K contains 4 ingredients: Vitamin K1, Vitamin D, and Vitamin K2 (listed twice in the formula). These are the active ingredients doing the work.
The product also contains hypoallergenic plant fiber and a vegetarian capsule as inactive ingredients — these are fillers and capsule material, not active components. Vitamin K1 and K2 both support blood clotting and bone health.
Vitamin D supports calcium absorption, bone strength, and immune function. Together they're designed to work on bone metabolism and clotting factors, though the evidence for bone support (osteoporosis) is described as possibly effective rather than proven.
Does it work?
Strong evidence
The data shows Vitamin K1 and K2 are effective for treating bleeding disorders — specifically low clotting factors, vitamin K deficiency states, and reversing warfarin's anticoagulant effects when medically needed. They're also rated as possibly effective for osteoporosis.
Vitamin D is effective for rickets, osteomalacia (soft bones from vitamin D lack), renal bone disease, and low parathyroid hormone states. The evidence we hold doesn't establish how well this particular combination works for general bone health in otherwise healthy people.
How safe is it?
Well-documented data
Orally, both vitamin K compounds are generally well tolerated. The most common side effects are mild: nausea, stomach upset, abdominal pain, and diarrhea — seen in a small number of people.
Serious side effects are rare. Vitamin D is also well tolerated at recommended doses, though very high doses over time can cause vitamin D toxicity, marked by high blood calcium and related symptoms.
Both Vitamin K1 and K2 are rated as likely safe in pregnancy and lactation. Vitamin D's pregnancy and lactation data isn't on file in our records, so talk with your doctor if you're pregnant or nursing before using this product.
Meds to double-check
Major interaction found
Double-check with your pharmacist if you take warfarin or other blood thinners — vitamin K can reduce how well they work. Also check if you're on heart rhythm medications (verapamil, diltiazem, digoxin), water pills for blood pressure (thiazides), the cholesterol drug atorvastatin, or calcipotriene for psoriasis.
If you take any CYP3A4 substrate medications, mention this product too.
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.
This product is worth considering if you have a documented vitamin K or D deficiency, or if your doctor has recommended bone or clotting support. If you take warfarin, any blood pressure or heart rhythm medication, water pills, or cholesterol drugs, you'll need to check with your pharmacist first — the vitamin K and D here can interact with those.
Pregnancy and nursing folks should also check in before starting.
Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI
Assessment coverage: 4 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Dec 13, 2022.
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 Synergy K, straight from the product label.
| Brand | Pure Encapsulations |
|---|---|
| Barcode (UPC) | 766298015682 |
| Net contents | 60 Capsule(s) |
| Market status | On market |
| Date entered into DSLD | Dec 13, 2022 |
| DSLD ID | 278366 |
| Product type | Vitamin |
| Supplement form | Capsule |
| Dietary claims / uses | All Other, Structure/Function |
| Intended target group(s) | Adult (18 - 50 Years), Women (not pregnant or lactating), 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 Synergy K by Pure Encapsulations, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| Vitamin K1 | 500 mcg | 417% |
| Vitamin D | 25 mcg | 125% |
| Vitamin K2 | 45 mcg | -- |
| Vitamin K2 | 1000 mcg | -- |
Other ingredients: hypoallergenic Plant Fiber, Vegetarian Capsule
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.
Storage
Store in a cool, dry place.
Suggested/Recommended/Usage/Directions
Recommendations: As a dietary supplement, take 1 capsule daily, with a meal, or as directed by a health professional.
Precautions
Warning: Not to be taken by pregnant or lactating women. Not for individuals taking blood thinning medications. If you have any health condition or are taking any medication, consult your health professional before use.
Keep out of the reach of children.
Use only if safety seal is intact.
General Statements
Scan to learn about our hypoallergenic supplements
Contents may not fill package in order to accommodate required labeling. Please rely on stated quantity.
Formulation
Certified Gluten-Free by the Gluten-Free Certification Organization, www.gluten.org
Supports bone and arterial health
Gluten-free, Non-GMO & Hypoallergenic
Gluten-free, Non-GMO & Hypoallergenic
Seals/Symbols
Certified Gluten-Free by the Gluten-Free Certification Organization, www.gluten.org
FDA Statement of Identity
Dietary Supplement
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.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
Synergy K by Pure Encapsulations 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 Synergy K by Pure Encapsulations
These are the 4 active ingredients this product is made of. Select any to open its full monograph.
Serving size1 Capsule(s) Dosage formCapsule 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 K1
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 K1 monograph & interactionsVitamin 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 K2
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 K2 monograph & interactionsVitamin K2
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 K2 monograph & interactionsOther (inactive) ingredients: Hypoallergenic Plant Fiber, Vegetarian Capsule. These complete the product’s ingredient list but are not active constituents.
Synergy K by Pure Encapsulations Drug Interactions
HelloPharmacist Interaction Report
Synergy K by Pure Encapsulations does interact with medications, and the most serious concern involves blood thinners.
Both Vitamin K1 and Vitamin K2 in this product can blunt the effects of warfarin (Coumadin), a blood thinner used to prevent clots. Vitamin K counteracts how warfarin works, so if you're on warfarin, you need to talk with your doctor or pharmacist before starting this supplement — dietary or supplement changes can matter here.
Read the full breakdown — every affected drug type, severity by severity
Vitamin D in this product has documented interactions with several medications. High-dose vitamin D can raise blood calcium levels, which creates risks with heart rhythm drugs like verapamil (Calan), diltiazem (Cardizem), and digoxin (Lanoxin), as well as with water pills (thiazide diuretics).
Vitamin D may also lower blood levels of the cholesterol drug atorvastatin (Lipitor) and theoretically increase absorption of aluminum, though that last concern mainly affects people with kidney disease. A small amount of concern exists for vitamin D and CYP3A4 substrates — a large group of medications whose levels your liver controls.
One other interaction involves calcipotriene (Dovonex), a vitamin D-like drug for psoriasis: combining it with vitamin D raises the risk of high blood calcium. Altogether, these interactions span 705 individual medications.
Run your complete medication list through the checker below before you start.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against Synergy K?
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 Synergy K interact with 715 drugs. Click any drug to see the details.
2 of the 4 ingredients in Synergy K interact with drugs. Each result below shows which ingredient is responsible. Vitamin D Vitamin K1
WarfarinWarfarin
How Warfarin interacts with Synergy K — through 2 ingredients. Tap an ingredient for the detail:
Vitamin K2Warfarin (coumadin) Major
Interaction Summary
Vitamin K can antagonize and reverse the therapeutic effects of warfarin.
Read the full Vitamin K2 + 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 Synergy K — through 2 ingredients. Tap an ingredient for the detail:
Vitamin K2Warfarin (coumadin) Major
Interaction Summary
Vitamin K can antagonize and reverse the therapeutic effects of warfarin.
Read the full Vitamin K2 + 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K — 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 Synergy K 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 K1
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 Synergy K, from the product label.
Pure Encapsulations
See all Pure Encapsulations products- Name
- Pure Encapsulations
- Street Address
- 490 Boston Post Road
- City
- Sudbury
- State
- MA
- Phone Number
- 1-800-753-2277
- Web Address
- www.PureEncapsulations.com
Synergy K by Pure Encapsulations: Common Questions
Does Synergy K by Pure Encapsulations interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Can I take Synergy K if I'm on warfarin?
What are the most common side effects?
Is this safe to take while pregnant?
Can I take this with my heart medication?
Will this help my osteoporosis?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if Synergy K 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 Synergy K’s Ingredients
Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.
Vitamin 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 → Herb & supplement monographVitamin 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 →Sources & How We Checked
Synergy K'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 K 11 references
- McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
- Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002.
- Crowther MA, Ageno W, Garcia D, et al. Oral vitamin K versus placebo to correct excessive anticoagulation in patients receiving warfarin: a randomized trial. Ann Intern Med. 2009;150(5):293-300. PubMed
- Dietary vitamin K guidance: an effective strategy for stable control of oral anticoagulation? Nutr Rev. 2010;68(3):178-81. PubMed
- Kim JS, Nafziger AN, Gaedigk A, et al. Effects of oral vitamin K on S- and R-warfarin pharmacokinetics and pharmacodynamics: enhanced safety of warfarin as a CYP2C9 probe. J Clin Pharmacol. 2001 Jul;41(7):715-22. PubMed
- Riegert-Johnson, D. L. and Volcheck, G. W. The incidence of anaphylaxis following intravenous phytonadione (vitamin K1): a 5-year retrospective review. Ann.Allergy Asthma Immunol. 2002;89(4):400-406. PubMed
- Dezee, K. J., Shimeall, W. T., Douglas, K. M., Shumway, N. M., and O'malley, P. G. Treatment of excessive anticoagulation with phytonadione (vitamin K): a meta-analysis. Arch.Intern.Med. 2-27-2006;166(4):391-397. DOI
- Dentali, F., Ageno, W., and Crowther, M. Treatment of coumarin-associated coagulopathy: a systematic review and proposed treatment algorithms. J.Thromb.Haemost. 2006;4(9):1853-1863. PubMed
- Caluwé R, Vandecasteele S, Van Vlem B, Vermeer C, De Vriese AS. Vitamin K2 supplementation in haemodialysis patients: a randomized dose-finding study. Nephrol Dial Transplant. 2014;29(7):1385-90.
- Huang ZB, Wan SL, Lu YJ, Ning L, Liu C, Fan SW. Does vitamin K2 play a role in the prevention and treatment of osteoporosis for postmenopausal women: a meta-analysis of randomized controlled trials. Osteoporos Int. 2015;26(3):1175-86. PubMed
- Hunnali CR, Devi U, Kitchanan S, Sethuraman G. Three Different Regimens for Vitamin K Birth Prophylaxis in Infants Born Preterm: A Randomized Clinical Trial. J Pediatr 2023;255:98-104. PubMed
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
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DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
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