Herb & supplement monograph

Vitamin D Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how Vitamin D interacts with medications. The heart of this page is the interaction list — every drug Vitamin D is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Vitamin D is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Vitamin D Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Vitamin D drug interaction appears low for most people. None of the listed interactions are rated major, and the great majority are minor rather than moderate.

Interactions deserving the most attention

The concerns that stand out mostly involve high doses of vitamin D raising calcium levels in the blood. That matters most with heart rhythm medicines like digoxin, verapamil, and diltiazem, where high calcium can raise arrhythmia risk or blunt the drug's effect, and with thiazide diuretics, which hold onto calcium and have been linked to high calcium when combined with vitamin D. A small human study also found vitamin D lowered atorvastatin levels, though cholesterol results did not change much, and combining it with the psoriasis cream calcipotriene could add to calcium-raising effects. Notably, these concerns center on high-dose vitamin D, not typical supplement amounts.

What the rest of the list means

The long list of minor interactions should not cause alarm. Most come from lab research suggesting vitamin D may affect an enzyme the body uses to clear many medications, an effect that is largely theoretical and has not been shown to cause meaningful problems in people.

Check your medications against Vitamin D

Based on HelloPharmacist’s Vitamin D interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Vitamin D

717 medications have a known interaction with Vitamin D, graded by severity. Select any drug for the full evidence-based detail.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against Vitamin D using our pharmacist-reviewed interaction data.

AI summaries are generated from our Vitamin D interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Vitamin D combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs Vitamin D affects

Every type of medication (drug category) Vitamin D is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 8 drug categories Vitamin D interacts with

AluminumAtorvastatin (lipitor)Calcipotriene (dovonex)Digoxin (lanoxin)Diltiazem (cardizem, Others)Thiazide DiureticsVerapamil (calan, Others)Cytochrome P450 3a4 (cyp3a4) Substrates

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.

Likelihood Probable Evidence B

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.

Likelihood Probable Evidence B

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.

Likelihood Probable Evidence D

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.

Likelihood Possible Evidence D

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.

Likelihood Probable Evidence B

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.

Likelihood Probable Evidence D

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.

Likelihood Probable Evidence B

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.

Likelihood Possible Evidence D

Monograph

Vitamin D: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed July 2026 ·

The bottom line

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, especially those with low sun exposure, benefit from supplementation, but more is not always better and very high doses can be harmful. Ask your pharmacist or doctor whether a blood test and supplement make sense for you.

Part used: Not applicable (a vitamin, not a plant part)
Common forms: Tablets, capsules, softgels, liquid drops, chewables, and injections

People commonly use it for

Bone health and osteoporosis
Correcting vitamin D deficiency
Immune system support
Muscle strength in older adults
General supplementation when sun exposure is low

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallLikely safe

Vitamin D is generally safe at recommended doses, but very high doses over time can cause toxicity.

PregnancyLikely Safe

When used orally and appropriately. Vitamin D is safe when used in doses below the tolerable upper intake level (UL) of 4000 IU (100 mcg) daily.

Read the full pregnancy detail

BreastfeedingLikely Safe

When used orally and appropriately. Vitamin D is safe when used in doses below the tolerable upper intake level (UL) of 4000 IU (100 mcg) daily.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Jump to a section

Overview

Vitamin D is a fat-soluble vitamin that your body needs for healthy bones, teeth, muscles, and immune function. It is sometimes called the "sunshine vitamin" because your skin makes it when it is exposed to sunlight.

You can also get vitamin D from a few foods, such as fatty fish (like salmon and mackerel), egg yolks, and foods that have vitamin D added to them, like milk and some cereals. Because few foods naturally contain much vitamin D, many people take supplements.

The two main forms in supplements are vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Vitamin D3 is the form your skin makes and is often considered slightly more effective at raising blood levels, but both are used.

How it works

Vitamin D from food, supplements, or sunlight is not active right away. Your liver and kidneys change it into its active form, called calcitriol.

The main job of active vitamin D is to help your intestines absorb calcium and phosphorus from food. These minerals are needed to build and maintain strong bones and teeth. Without enough vitamin D, your body cannot use calcium well, no matter how much you take in.

Vitamin D receptors are also found in many other tissues, including immune cells and muscle. This is why researchers study its role in immunity and muscle function, though much of this work is still early or based on laboratory studies.

Effectiveness

Does Vitamin D work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by Dr. Brian Staiger, PharmD.

Evidence overview · 127 uses evaluated

6 Effective 2 Likely effective 6 Possibly effective 7 Leans ineffective 106 Insufficient evidence

How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.

2Likely EffectiveGood evidence, though not yet conclusive.

3Possibly EffectiveSome evidence suggests a benefit.

4Possibly IneffectiveSome evidence it may not help.

5Likely IneffectiveFairly strong evidence it doesn’t help.

6IneffectiveStrong evidence it doesn’t work.

7Insufficient Reliable Evidence to RateToo little research to say either way.

Effective Familial hypophosphatemia