Vitamin K + Diltiazem

Vitamin K has 2 major, known drug interactions in our database — Diltiazem isn’t one of them. If you take anything else, check it against the full list below.

We haven’t checked that one against Vitamin K yet — ask our pharmacists directly.

Covers the 2,830 medications we’ve checked against Vitamin K. Pick one to open its full report.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

These two come up together because they touch the same health topic — not because they do the same job. Diltiazem is a prescription medicine with approved uses on its FDA label. Vitamin K is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Diltiazem is prescribed for: Oral extended-release forms of diltiazem — including Matzim LA, Cardizem LA, Cartia, Cartia XT, Tiadylt ER, and various generic capsules and tablets — are used to treat high blood pressure (hypertension) and chronic stable angina (chest pain brought on by activity). Some capsule formulations, including Cartia, Cartia XT, and certain generics, are also approved for angina due to coronary artery spasm (sudden chest pain caused by a sudden tightening of a coronary artery). Injectable forms of diltiazem are used in hospital settings to temporarily slow a dangerously fast heart rate in atrial fibrillation or atrial flutter (rapid, irregular heart rhythms), and to restore a normal heart rhythm in paroxysmal supraventricular tachycardia (PSVT) — sudden episodes of a very fast but regular heartbeat originating above the heart's lower chambers.

Vitamin K has been studied for:

• Kidney failure studied, not established Vitamin K has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

  Vitamin K for kidney failure

  It is unclear if oral vitamin K2 reduces the incidence or severity of muscle cramps in adults with kidney failure.

• Stroke studied, not established Vitamin K has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

  Vitamin K for stroke

  It is unclear if dietary intake of vitamin K1 reduces the risk of stroke.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Diltiazem on your own; if you are taking Vitamin K for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Vitamin K or Diltiazem, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

• Is Terry Naturally Anxiocalm Safe With Amlodipine? Answered by Dr. Brian Staiger, PharmD · January 2023 ›
• Is Garlique Safe To Take With Blood Pressure Medication? Answered by Dr. Brian Staiger, PharmD · January 2023 ›
• Are Diltiazem ER Tablets And Capsules Interchangeable? Answered by Dr. Brian Staiger, PharmD · February 2022 ›

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

This page covers Vitamin K only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Diltiazem page lists 260 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Coleus (major) and Grapefruit (major).

By severity: 7 major · 214 moderate · 39 minor.

Open the Diltiazem interaction page ›

We hold 5,292 real supplement products containing Vitamin K, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Vitamin K. Even though Vitamin K itself has no known interaction with Diltiazem, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Natural Medicines records Diltiazem as a medicine that can lower these. This is not an interaction with Vitamin K — it is a separate effect of the medicine, and it is a reason some people are advised to supplement rather than to avoid one:

• COENZYME Q10›
• VITAMIN C›

Read the full Diltiazem nutrient depletion report ›

Vitamin K is itself a nutrient we track — see which medications may deplete VITAMIN K.

Depletion records come from the licensed Natural Medicines database. Do not start a supplement on the strength of this page — ask your pharmacist or doctor whether it applies to you.