Interactions on record — worth a quick check against your medications. Based on 6 of 7 ingredients. Check your meds →
Dietary supplement

Z-Lozenge + Natural Fruit Flavor Ingredients & Drug Interactions

by DC

Z-Lozenge + Natural Fruit Flavor label
See full label image
Lozenge Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Z-Lozenge + Natural Fruit Flavor 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

The interaction bottom line Most serious interaction: Moderate

Z-Lozenge + Natural Fruit Flavor is a dietary supplement by DC with 7 active ingredients. Its ingredients are commonly taken for morning sickness in pregnancy, premenstrual syndrome (pms), preventing or treating b6 deficiency.Based on those ingredients, 2,107 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Slippery Elm bark powder, Vitamin D3, Vitamin B6. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Z-Lozenge + Natural Fruit Flavor by DC

Ask about any prescription or over-the-counter medication and we check it for interactions with Z-Lozenge + Natural Fruit Flavor by DC — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Z-Lozenge + Natural Fruit Flavor by DC

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.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Partial disclosure
Ingredient Transparency · database check
Partial

Most active ingredients list an amount, but at least one is hidden in a blend or missing.

Why this rating?
  • The label discloses an exact amount for 4 of its 7 active ingredients.
  • “Proprietary Blend” is a proprietary blend — the label gives one combined amount (22 mg) without saying how much of each component you get.

DC Z-Lozenge + Natural Fruit Flavor contains 7 active ingredients. Vitamin B6 supports nerve and red-blood-cell function.

Vitamin D3 helps your body absorb calcium and supports bone health. Zinc is essential for immune function and wound healing.

Vitamin C is a key antioxidant that supports collagen and immunity. Royal Jelly, a nutrient-rich secretion from honeybees, is included in a proprietary blend alongside Slippery Elm bark powder, which contains mucilage that may coat and soothe your throat.

White Willow bark extract rounds out the blend. The lozenge also contains inactive ingredients like dextrose, fructose, sorbitol, and magnesium stearate to form and flavor the tablet.

Does it work?

Strong evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed

This product doesn't appear to be marketed for a specific use, so we graded its ingredients' overall clinical evidence instead.

Strong

Strong clinical evidence supports its ingredients for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredients' overall clinical evidence instead.
  • On file: Sideroblastic anemia — rated "Effective" (Vitamin B6) (Natural Medicines).
  • On file: Familial hypophosphatemia — rated "Effective" (Vitamin D) (Natural Medicines).
  • On file: Osteomalacia — rated "Effective" (Vitamin D) (Natural Medicines).
  • On file: Renal osteodystrophy — rated "Effective" (Vitamin D) (Natural Medicines).
  • On file: Rickets — rated "Effective" (Vitamin D) (Natural Medicines).

Vitamin B6 is Effective for sideroblastic anemia and vitamin B6 deficiency, and Likely Effective for high homocysteine levels. It is Possibly Effective for pregnancy-induced nausea and vomiting, though use during pregnancy requires a doctor's guidance.

Vitamin D3 is Effective for rickets, osteomalacia, renal bone disease, and related calcium-metabolism disorders. Zinc is Effective for zinc deficiency and Likely Effective for Wilson disease; it is Possibly Effective for acne and age-related macular degeneration.

Vitamin C is Effective for vitamin C deficiency and Possibly Effective for several conditions including cataracts and exercise-related respiratory infections. For Royal Jelly, only menopausal symptoms show Possibly Effective evidence.

Slippery Elm bark and White Willow bark extract have insufficient or no reliable evidence in our data to establish their effectiveness for any condition.

The evidence, ingredient by ingredient Vitamin B6 Slippery Elm Royal Jelly Vitamin D Zinc Vitamin C

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 6 of the 6 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 6 of 6.
  • General safety write-ups exist for 6 of 6.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Vitamin B6 is well tolerated in doses below 100 mg daily but can cause nerve damage (sensory neuropathy) at very high doses, especially above 1,000 mg per day or with long-term use. Common side effects include headache, nausea, and abdominal pain.

Vitamin D3 is generally safe at recommended doses but can cause toxicity with excessive long-term use; symptoms include high blood calcium levels and kidney problems. Zinc is well tolerated below the tolerable upper limit of 40 mg daily; higher doses may cause stomach cramps, diarrhea, and a metallic taste, and may increase copper deficiency risk over time.

Vitamin C is generally safe but can cause diarrhea, kidney stones (especially in those prone to them), and abdominal cramps at very high doses above 2 grams daily. Royal Jelly is well tolerated overall but can trigger serious allergic reactions — including anaphylaxis — in people with a history of asthma or allergies.

Slippery Elm is generally well tolerated for short-term use but has limited safety data; White Willow bark extract safety data are not on file. None of the ingredients have pregnancy or breastfeeding safety ratings in our data; talk with your doctor before use during pregnancy or while nursing.

Side effects, ingredient by ingredient Vitamin B6 Slippery Elm Royal Jelly Vitamin D Zinc Vitamin C

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 6 of the 6 matched ingredients can interact with medications — Royal Jelly, Vitamin D, Vitamin B6, Slippery Elm, Zinc, among others.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; cancer treatments; heart-rhythm medications; Parkinson's medications.
  • For scale: 2,108 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Check the following medication types before taking this product, worst severity first: antihypertensive drugs (blood-pressure medications), blood thinners like warfarin, heart rhythm drugs (verapamil, diltiazem, digoxin), thyroid medications (levothyroxine), birth control or hormone therapy, quinolone and tetracycline antibiotics, cephalexin, penicillamine, and any HIV or cancer medications. If you take any oral drug alongside the lozenge, ask your pharmacist about timing, since Slippery Elm may slow absorption of medications taken at the same time.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glancePartially disclosed formula with strong clinical evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.

This lozenge may help with vitamin and mineral deficiencies and immune support if you have no relevant medication interactions. If you take antihypertensive drugs, blood thinners like warfarin, heart rhythm medications, thyroid drugs, birth control, antibiotics, or HIV medications, check your exact drug names in the tool below before starting.

People with asthma or allergies should be cautious of royal jelly's risk of serious allergic reactions. Ask your pharmacist to review your specific medications and medical history before you begin.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 6 of 7 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Feb 23, 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

At a glance

General information

Key facts about Z-Lozenge + Natural Fruit Flavor, straight from the product label.

Brand DC
Net contents 120 Lozenge(s)
Market status On market
Date entered into DSLD Feb 23, 2022
DSLD ID 266416
Product type Other Combinations
Supplement form Lozenge
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Women (not pregnant or lactating), Gluten Free
From the label
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 Z-Lozenge + Natural Fruit Flavor by DC, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Lozenge(s)
Maximum serving Sizes:
3 Lozenge(s)
Servings per container
120
IngredientAmount% DV
Vitamin B62 mg118%
Proprietary Blend22 mg--
Vitamin D320 mcg100%
Zinc25 mg227%
Slippery Elm bark powder0 NP--
Royal Jelly0 NP--
White Willow bark ext.0 NP--
Vitamin C30 mg33%

Other ingredients: Dextrose, Fructose, Sorbitol, natural Fruit flavor, Vegetable Stearic Acid, Silica, Vegetable Magnesium Stearate

Tap any ingredient to jump to its full detail below.

Label statements
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.
Suggested/Recommended/Usage/Directions

Directions: As a dietary supplement, take 1 to 3 lozenges daily. Keep lozenge in mouth until dissolved.

Precautions

Tamper Evident: Do not use this product if imprinted foil seal under cap is broken or missing.

Keep out of reach of children.

Caution: If you are pregnant or nursing do not take this product.

Formulation

Mfg. in an FDA Registered Facility using Good Manufacturing Practices (GMPs)

Conforms to USP <2091> for weight.

Made in USA

Gluten free

Nutritionally supports immune system health

Storage

Keep tightly closed. Store at room temperature: 59 degrees - 86 degrees F (15 degrees to 30 degrees C).

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.

Formula

Now with Vitamin D3

Dietary Supplement of Zinc, Vitamin C, Vitamin D3, and B-6

Seals/Symbols

Quali Pure

FDA Statement of Identity

Dietary Supplement of Zinc, Vitamin C, Vitamin D3, and B-6

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Z-Lozenge + Natural Fruit Flavor by DC label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Z-Lozenge + Natural Fruit Flavor label

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)
What’s inside

The Ingredients in Z-Lozenge + Natural Fruit Flavor by DC

These are the 7 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Lozenge(s) Dosage formLozenge Servings per container120 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 B6

Interacts with
210 drugs
2 mg per serving Form: Pyridoxine Hydrochloride

Vitamin B6 (pyridoxine) is an essential water-soluble vitamin that your body needs for metabolism, brain function, and making red blood cells. It is b...

Vitamin B6 monograph & interactions

Proprietary Blend

22 mg per serving

Vitamin D3

Interacts with
715 drugs
20 mcg per serving Form: Cholecalciferol

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 & interactions

Zinc

Interacts with
67 drugs
25 mg per serving Form: Zinc Citrate

Zinc is an essential mineral that your body needs for immune function, wound healing, taste, and smell. Most people get enough from food, but suppleme...

Zinc monograph & interactions

Vitamin C

Interacts with
207 drugs
30 mg per serving Form: L-Ascorbic Acid, Sodium Ascorbate

Vitamin C (ascorbic acid) is an essential nutrient your body needs but cannot make, so you must get it from food or supplements. It's important for im...

Vitamin C monograph & interactions

Other (inactive) ingredients: Dextrose, Fructose, Sorbitol, Natural Fruit flavor, Vegetable Stearic Acid, Silica, Vegetable Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Z-Lozenge + Natural Fruit Flavor by DC Drug Interactions

Want to check YOUR meds against Z-Lozenge + Natural Fruit Flavor?

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 checker
2,107Drugs
2,061 Moderate 46 Minor

Ingredients driving the most interactions

Slippery Elm bark powder 2,022
Vitamin D3 715
Vitamin B6 210
Vitamin C 207
Royal Jelly 174

Individual Drug Interactions

The ingredients in Z-Lozenge + Natural Fruit Flavor interact with 2,107 drugs. Click any drug to see the details.

6 of the 7 ingredients in Z-Lozenge + Natural Fruit Flavor interact with drugs. Each result below shows which ingredient is responsible. Slippery Elm bark powder Vitamin D3 Vitamin B6 Vitamin C Royal Jelly Zinc

Each ingredient & the kinds of drugs it affects

For each ingredient in Z-Lozenge + Natural Fruit Flavor 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.

Slippery Elm bark powder1 drug type · 2,022 drugs

Oral Drugs

Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Slippery elm inner bark contains mucilage, which may interfere with the absorption of orally administered drugs.

Likelihood Possible Evidence D
Slippery Elm bark powder full monograph & interactions

Vitamin D38 drug types · 715 drugs

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
Vitamin D3 full monograph & interactions

Vitamin B65 drug types · 210 drugs

Amiodarone (Cordarone)

Theoretically, vitamin B6 might increase the photosensitivity caused by amiodarone.
Despite initial case reports suggesting that pyridoxine may have a protective effect against amiodarone-induced photosensitivity, preliminary clinical research suggests that pyridoxine may actually exacerbate this adverse effect.

Likelihood Possible Evidence B
Antihypertensive Drugs

Theoretically, vitamin B6 may have additive effects when used with antihypertensive drugs.
Research in hypertensive rats shows that vitamin B6 can decrease systolic blood pressure. Similarly, clinical research in patients with hypertension shows that taking high doses of vitamin B6 may reduce systolic and diastolic blood pressure, possibly by reducing plasma levels of epinephrine and norepinephrine.

Likelihood Possible Evidence B
Phenobarbital (Luminal)

High doses of vitamin B6 may reduce the levels and clinical effects of phenobarbital.
Preliminary clinical evidence suggests that vitamin B6 200 mg daily can reduce plasma levels of phenobarbital, possibly by increasing metabolism. It is not known whether lower doses have any effect. Advise people taking phenobarbital to avoid high doses of vitamin B6.

Likelihood Possible Evidence D
Phenytoin (Dilantin)

High doses of vitamin B6 may reduce the levels and clinical effects of phenytoin.
Preliminary clinical evidence suggests that vitamin B6 200 mg daily can reduce plasma levels of phenytoin, possibly by increasing metabolism. It is not known whether lower doses have any effect. Advise people taking phenytoin to avoid high doses of vitamin B6.

Likelihood Possible Evidence D
Levodopa

Vitamin B6 may increase the metabolism of levodopa when taken alone, but not when taken in conjunction with carbidopa.
Vitamin B6 (pyridoxine) enhances the metabolism of levodopa, reducing its clinical effects. However, this interaction does not occur when carbidopa is used concurrently with levodopa (Sinemet). Therefore, it is not likely to be a problem in most people.

Likelihood Unlikely Evidence D
Vitamin B6 full monograph & interactions

Vitamin C13 drug types · 207 drugs

Alkylating Agents

Theoretically, antioxidant effects of vitamin C might reduce the effectiveness of alkylating agents.
The use of antioxidants like vitamin C during chemotherapy is controversial. There is concern that antioxidants could reduce the activity of chemotherapy drugs that generate free radicals, such as cyclophosphamide, chlorambucil, carmustine, busulfan, and thiotepa. In contrast, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that could interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effect, if any, antioxidants such as vitamin C have on chemotherapy.

Likelihood Possible Evidence D
Aluminum

Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.
Research in animals and humans shows that vitamin C increases aluminum absorption, theoretically by chelating aluminum and keeping it in solution where it is available for absorption. In people with normal renal function, urinary excretion of aluminum will likely increase, making aluminum retention and toxicity unlikely. Patients with renal failure who take aluminum-containing compounds such as phosphate binders should avoid vitamin C supplements in doses above the recommended dietary allowances.

Likelihood Probable Evidence B
Antitumor Antibiotics

Theoretically, the antioxidant effects of vitamin C might reduce the effectiveness of antitumor antibiotics.
The use of antioxidants like vitamin C during chemotherapy is controversial. There is concern that antioxidants could reduce the activity of chemotherapy drugs which generate free radicals, such as doxorubicin. In contrast, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that could interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effects, if any, antioxidants such as vitamin C have on chemotherapy.

Likelihood Possible Evidence D
Estrogens

Vitamin C might increase blood levels of estrogens.
Increases in plasma estrogen levels of up to 55% occur under some circumstances when vitamin C is taken concurrently with oral contraceptives or hormone replacement therapy, including topical products. It is suggested that vitamin C prevents oxidation of estrogen in the tissues, regenerates oxidized estrogen, and reduces sulfate conjugation of estrogen in the gut wall. When tissue levels of vitamin C are high, these processes are already maximized and supplemental vitamin C does not have any effect on estrogen levels. Increases in plasma estrogen levels may occur when patients who are deficient in vitamin C take supplements. Monitor these patients for estrogen-related side effects.

Likelihood Probable Evidence B
Fluphenazine (Prolixin)

Theoretically, vitamin C might decrease levels of fluphenazine.
In one patient there was a clinically significant decrease in fluphenazine levels when vitamin C (500 mg twice daily) was started. The mechanism is not known, and there is no further data to confirm this interaction.

Likelihood Possible Evidence D
Indinavir (Crixivan)

Vitamin C can modestly reduce indinavir levels.
One pharmacokinetic study shows that taking vitamin C 1 gram orally once daily along with indinavir 800 mg orally three times daily reduces the area under the concentration-time curve of indinavir by 14%. The mechanism of this interaction is unknown, but it is unlikely to be clinically significant in most patients. The effect of higher doses of vitamin C on indinavir levels is unknown.

Likelihood Probable Evidence B
Levothyroxine (Synthroid, Others)

Vitamin C can increase levothyroxine absorption.
Two clinical studies in adults with poorly controlled hypothyroidism show that swallowing levothyroxine with a glass of water containing vitamin C 500-1000 mg in solution reduces thyroid stimulating hormone (TSH) levels and increases thyroxine (T4) levels when compared with taking levothyroxine alone. This suggests that vitamin C increases the oral absorption of levothyroxine, possibly due to a reduction in pH.

Likelihood Probable Evidence B
Warfarin (Coumadin)

High-dose vitamin C might reduce the levels and effectiveness of warfarin.
Vitamin C in high doses may cause diarrhea and possibly reduce warfarin absorption. There are reports of two people who took up to 16 grams daily of vitamin C and had a reduction in prothrombin time. Lower doses of 5-10 grams daily can also reduce warfarin absorption. In many cases, this does not seem to be clinically significant. However, a case of warfarin resistance has been reported for a patient who took vitamin C 500 mg twice daily. Cessation of vitamin C supplementation resulted in a rapid increase in international normalized ratio (INR). Tell patients taking warfarin to avoid taking vitamin C in excessively high doses (greater than 10 grams daily). Lower doses may be safe, but the anticoagulation activity of warfarin should be monitored. Patients who are stabilized on warfarin while taking vitamin C should avoid adjusting vitamin C dosage to prevent the possibility of warfarin resistance.

Likelihood Possible Evidence D
Acetaminophen (Tylenol, Others)

High-dose vitamin C might slightly prolong the clearance of acetaminophen.
A small pharmacokinetic study in healthy volunteers shows that taking high-dose vitamin C (3 grams) 1.5 hours after taking acetaminophen 1 gram slightly increases the apparent half-life of acetaminophen from around 2.3 hours to 3.1 hours. Ascorbic acid competitively inhibits sulfate conjugation of acetaminophen. However, to compensate, elimination of acetaminophen glucuronide and unconjugated acetaminophen increases. This effect is not likely to be clinically significant.

Likelihood Probable Evidence B
Aspirin

Acidification of the urine by vitamin C might increase aspirin levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams daily of vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction is not clinically significant.

Likelihood Possible Evidence B
Choline Magnesium Trisalicylate (Trilisate)

Acidification of the urine by vitamin C might increase choline magnesium trisalicylate levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams daily of vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction probably is not clinically significant.

Likelihood Possible Evidence B
Niacin

Vitamin C might decrease the beneficial effects of niacin on high-density lipoprotein (HDL) cholesterol levels.
A combination of niacin and simvastatin (Zocor) effectively raises HDL cholesterol levels in patients with coronary disease and low HDL levels. Clinical research shows that taking a combination of antioxidants (vitamin C, vitamin E, beta-carotene, and selenium) along with niacin and simvastatin (Zocor) attenuates this rise in HDL, specifically the HDL-2 and apolipoprotein A1 fractions, by more than 50% in patients with coronary disease. It is not known whether this adverse effect is due to a single antioxidant such as vitamin C, or to the combination. It also is not known whether it will occur in other patient populations.

Likelihood Possible Evidence A
Salsalate (Disalcid)

Acidification of the urine by vitamin C might increase salsalate levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams/day vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction probably is not clinically significant.

Likelihood Possible Evidence B
Vitamin C full monograph & interactions

Royal Jelly2 drug types · 174 drugs

Antihypertensive Drugs

Theoretically, royal jelly might increase the risk of hypotension when taken with antihypertensive drugs.
Animal research suggests that royal jelly might lower blood pressure.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Royal jelly might increase the risk of bleeding when taken with warfarin.
In one case, an 87-year-old male who was previously stabilized on warfarin developed hematuria and was found to have an INR of 7.29 after taking a royal jelly supplement for one week.

Likelihood Possible Evidence D
Royal Jelly full monograph & interactions

Zinc10 drug types · 67 drugs

Bictegravir/Emtricitabine/Tenofovir Alafenamide (Biktarvy)

Theoretically, zinc might decrease levels of bictegravir/emtricitabine/tenofovir alafenamide by reducing its absorption.
Advise patients that bictegravir/emtricitabine/tenofovir alafenamide should be taken at least 2 hours before or 6 hours after zinc containing products.

Likelihood Probable Evidence D
Cephalexin (Keflex)

Zinc might decrease cephalexin levels by chelating with cephalexin in the gut and preventing its absorption.
A pharmacokinetic study shows that zinc sulfate 250 mg taken concomitantly with cephalexin 500 mg decreases peak levels of cephalexin by 31% and reduces the exposure to cephalexin by 27%. Also, taking zinc sulfate 3 hours before cephalexin decreases peak levels of cephalexin by 11% and reduces the exposure to cephalexin by 18%. By decreasing cephalexin levels, zinc might increase the risk of treatment failure. This effect does not occur when zinc is taken 3 hours after the cephalexin dose. To avoid an interaction, advise patients take zinc sulfate 3 hours after taking cephalexin.

Likelihood Probable Evidence B
Cisplatin (Platinol-Aq)

Theoretically, zinc might interfere with the therapeutic effects of cisplatin.
Animal research suggests that zinc stimulates tumor cell production of the protein metallothionein, which binds and inactivates cisplatin. It is not known whether zinc supplements or high dietary zinc intake can cause clinically significant interference with cisplatin therapy. Cisplatin might also increase zinc excretion.

Likelihood Possible Evidence D
Integrase Inhibitors

Theoretically, taking zinc along with integrase inhibitors might decrease the levels and clinical effects of these drugs.
Zinc is a divalent cation. Pharmacokinetic studies have shown that other divalent cations such as calcium and iron can decrease blood levels of the integrase inhibitor dolutegravir through chelation.

Likelihood Possible Evidence D
Penicillamine (Cuprimine, Depen)

Zinc might reduce the levels and clinical effects of penicillamine.
By forming an insoluble complex with penicillamine, zinc interferes with penicillamine absorption and activity. Zinc supplements reduce the efficacy of low-dose penicillamine (0.5-1 gram/day), but do not seem to affect higher doses (1-2.75 gram/day), provided dosing times are separated. Advise patients to take zinc and penicillamine at least 2 hours apart.

Likelihood Probable Evidence B
Quinolone Antibiotics

Zinc can decrease the levels and clinical effects of quinolones antibiotics.
Quinolones form complexes with zinc in the gastrointestinal tract, reducing absorption of both the quinolone and zinc if taken at the same time. Advise patients to take these drugs at least 2 hours before, or 4-6 hours after, zinc supplements.

Likelihood Probable Evidence B
Ritonavir (Norvir)

Zinc modestly reduces levels of ritonavir.
Clinical research shows that zinc might reduce serum ritonavir levels by chelating with ritonavir in the gut and preventing its absorption. In patients with HIV, ritonavir is taken with atazanavir to prevent the metabolism and increase the effects of atazanavir. A pharmacokinetic study shows that, in patients being treated with atazanavir/ritonavir, co-administration of zinc sulfate (Solvazinc tablets) 125 mg as a single dose or as multiple daily doses for 2 weeks reduces plasma levels of ritonavir by about 16%. However, atazanavir levels still remains high enough to prevent HIV virus replication. Therefore, the decrease in ritonavir levels is not likely to be clinically significant.

Likelihood Probable Evidence B
Tetracycline Antibiotics

Zinc might reduce levels of tetracycline antibiotics.
Tetracyclines form complexes with zinc in the gastrointestinal tract, which can reduce absorption of both the tetracycline and zinc when taken at the same time. Taking zinc sulfate 200 mg with tetracycline reduces absorption of the antibiotic by 30% to 40%. Demeclocycline and minocycline cause a similar interaction. However, doxycycline does not seem to interact significantly with zinc. Advise patients to take tetracyclines at least 2 hours before, or 4-6 hours after, zinc supplements to avoid any interactions.

Likelihood Probable Evidence B
Amiloride (Midamor)

Amiloride can modestly reduce zinc excretion and increase zinc levels.
Clinical research shows that amiloride can reduce urinary zinc excretion, especially at doses of 10 mg per day or more. This zinc-sparing effect can help to counteract zinc losses caused by thiazide diuretics, but it is unlikely to cause zinc toxicity at usual amiloride doses. The other potassium-sparing diuretics, spironolactone (Aldactone) and triamterene (Dyrenium), do not seem to have a zinc-sparing effect.

Likelihood Probable Evidence B
Atazanavir (Reyataz)

Zinc modestly reduces levels of atazanavir, although this effect does not seem to be clinically significant.
Clinical research shows that zinc might decrease serum atazanavir levels by chelating with atazanavir in the gut and preventing its absorption. Although a single dose of zinc sulfate (Solvazinc tablets) 125 mg orally does not affect atazanavir concentrations in patients being treated with atazanavir/ritonavir, co-administration of zinc sulfate 125 mg daily for 2 weeks reduces plasma levels of atazanavir by about 22% in these patients. However, despite this decrease, atazanavir levels still remain at high enough concentrations for the prevention of HIV virus replication.

Likelihood Probable Evidence B
Zinc full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Z-Lozenge + Natural Fruit Flavor, from the product label.

DC

See all DC products
Name
Dee Cee Laboratories, Inc.
Street Address
304 Dee Cee Rd.
City
White House
State
TN
ZipCode
37188
Pharmacist Counseling Corner

Z-Lozenge + Natural Fruit Flavor by DC: Common Questions

Does Z-Lozenge + Natural Fruit Flavor by DC interact with any medications?
Yes. Based on its ingredients, Z-Lozenge + Natural Fruit Flavor has a known interaction with 2,107 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Z-Lozenge + Natural Fruit Flavor contains 7 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Can I take this if I'm pregnant?
We don't have pregnancy safety data on file for most of these ingredients. Vitamin B6 is sometimes used for morning sickness but only under a doctor's guidance. Talk with your doctor or pharmacist before taking this product during pregnancy — they can weigh the benefits and risks for your specific situation.
Is royal jelly safe for me if I have allergies or asthma?
Royal jelly can trigger serious allergic reactions in people with asthma or a history of allergies, ranging from itching and swelling to anaphylaxis in severe cases. If you have asthma or allergies, skip this product or check with your doctor first.
What are the common side effects of vitamin B6 at normal doses?
At doses below 100 mg daily, vitamin B6 is well tolerated. The most common side effects are headache, nausea, abdominal pain, and loss of appetite. High doses over time can cause nerve damage, so stick to recommended amounts.
Will this interfere with my antibiotics?
Yes — zinc in this lozenge can reduce absorption of quinolone, tetracycline, and cephalexin antibiotics if taken at the same time. Ask your pharmacist whether you should space out these doses, typically 2-6 hours apart depending on the antibiotic.
Is this safe for long-term daily use?
The individual vitamins in this product are generally well tolerated at normal supplement doses, but Slippery Elm has limited long-term safety data. Use as directed on the label and talk with your pharmacist if you plan to take it for many months.
Can I take this with my vitamin D supplement?
This lozenge already contains vitamin D3, so taking it with another vitamin D supplement could raise your intake above recommended limits and increase the risk of vitamin D toxicity. Check the total dose with your pharmacist.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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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.

Z-Lozenge + Natural Fruit Flavor label
Go deeper

The Full Monographs Behind Z-Lozenge + Natural Fruit Flavor’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Vitamin B6

Interacts with 210 drugs

Vitamin B6 (pyridoxine) is an essential water-soluble vitamin that your body needs for metabolism, brain function, and making red blood cells. It is best known for helping with pregnancy-rel...

Read the full Vitamin B6 monograph → Herb & supplement monograph

Slippery Elm

Interacts with 2,022 drugs

Slippery elm is a traditional herbal remedy made from the inner bark of a North American elm tree, used mainly to soothe sore throats and irritated digestive tracts. Its mucilage can coat an...

Read the full Slippery Elm monograph → Herb & supplement monograph

Royal Jelly

Interacts with 174 drugs

Royal jelly is a nutrient-rich substance made by worker bees to feed the queen bee. People take it for menopause symptoms, energy, skin, and immune support, but solid human evidence is limit...

Read the full Royal Jelly monograph → Herb & supplement monograph

Vitamin D

Interacts with 715 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, especially those with low sun exposure,...

Read the full Vitamin D monograph → Herb & supplement monograph

Zinc

Interacts with 67 drugs

Zinc is an essential mineral that your body needs for immune function, wound healing, taste, and smell. Most people get enough from food, but supplements can help correct or prevent a defici...

Read the full Zinc monograph → Herb & supplement monograph

Vitamin C

Interacts with 207 drugs

Vitamin C (ascorbic acid) is an essential nutrient your body needs but cannot make, so you must get it from food or supplements. It's important for immune function, collagen, and acts as an...

Read the full Vitamin C monograph →
Sources

Sources & How We Checked

Z-Lozenge + Natural Fruit Flavor'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.

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 214 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 B6 32 references
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  6. Baxter P, Aicardi J. Neonatal seizures after pyridoxine use. Lancet 1999;354:2082-3. PubMed
  7. Bendich A, Cohen M. Vitamin B6 safety issues. Ann N Y Acad Sci 1990;585:321-30.
  8. Schaumburg H, Kaplan J, Windebank A. Sensory neuropathy from pyridoxine abuse. A new megavitamin syndrome. N Engl J Med 1983;309:445-8. PubMed
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  10. Lewis PJ. Pain in the hand and wrist. Pyridoxine supplements may help patients with carpal tunnel syndrome. BMJ 1995;310:1534. PubMed
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  12. Mulrow JP, Mulrow CD, McKenna WJ. Pyridoxine and amiodarone-induced photosensitivity. Ann Intern Med 1985;103:68-9. PubMed
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  16. Jansen T, Romiti R, Kreuter A, Altmeyer P. Rosacea fulminans triggered by high-dose vitamins B6 and B12. J Eur Acad Dermatol Venereol 2001;15:484-5..
  17. Chittumma P, Kaewkiattikun K, Wiriyasiriwach B. Comparison of the effectiveness of ginger and vitamin B6 for treatment of nausea and vomiting in early pregnancy: a randomized double-blind controlled trial. J Med Assoc Thai 2007;90:15-20.
  18. Hatzitolios, A., Iliadis, F., Katsiki, N., and Baltatzi, M. Is the anti-hypertensive effect of dietary supplements via aldehydes reduction evidence based? A systematic review. Clin Exp.Hypertens. 2008;30(7):628-639. PubMed
  19. Vasdev, S., Ford, C. A., Parai, S., Longerich, L., and Gadag, V. Dietary vitamin B6 supplementation attenuates hypertension in spontaneously hypertensive rats. Mol.Cell Biochem. 1999;200(1-2):155-162.
  20. de, Vogel S., Dindore, V., van, Engeland M., Goldbohm, R. A., van den Brandt, P. A., and Weijenberg, M. P. Dietary folate, methionine, riboflavin, and vitamin B-6 and risk of sporadic colorectal cancer. J Nutr 2008;138(12):2372-2378. PubMed
  21. Hagen, I., Nesheim, B. I., and Tuntland, T. No effect of vitamin B-6 against premenstrual tension. A controlled clinical study. Acta Obstet.Gynecol.Scand. 1985;64(8):667-670. PubMed
  22. Aybak, M., Sermet, A., Ayyildiz, M. O., and Karakilcik, A. Z. Effect of oral pyridoxine hydrochloride supplementation on arterial blood pressure in patients with essential hypertension. Arzneimittelforschung. 1995;45(12):1271-1273.
  23. Lal, K. J., Dakshinamurti, K., and Thliveris, J. The effect of vitamin B6 on the systolic blood pressure of rats in various animal models of hypertension. J Hypertens. 1996;14(3):355-363. PubMed
  24. Lauritzen CH, Reuter HD, Repges R, Bohnert K, and Schmidt U. Treatment of premenstrual tension syndrome with Vitex agnus castus. Controlled, double-blind study versus pyridoxine. Phytomed 1997;4(3):183-189. PubMed
  25. Fonseca VA, Lavery LA, Thethi TK, et al. Metanx in type 2 diabetes with peripheral neuropathy: A randomized trial. Am J Med 2013;126(2):141-9. PubMed
  26. Hankey GJ, Eikelboom JW, Yi Q, et al. Treatment with B vitamins and incidence of cancer in patients with previous stroke or transient ischemic attack: Results of a randomized placebo-controlled trial. Stroke 2012;43(6):1572-7. PubMed
  27. Hoyer-Kuhn H, Kohbrok S, Volland R, Franklin J, Hero B, Beck BB, Hoppe B. Vitamin B6 in primary hyperoxaluria I: first prospective trial after 40 years of practice. Clin J Am Soc Nephrol. 2014 Mar;9(3):468-77. PubMed
  28. Mahmoud A, Tabassum S, Al Enazi S, et al. Amelioration of levetiracetam-induced behavioral side effects by pyridoxine. A randomized double blind controlled study. Pediatr Neurol 2021;119:15-21. PubMed
  29. Gupta M, Gallante B, Bamberger JN, et al. Prospective randomized evaluation of idiopathic hyperoxaluria treatments. J Endourol 2021;35(12):1844-1851. PubMed
  30. Li H, Chen M, Liang S, et al. Excessive vitamin B6 during treatment is related to poor prognosis of patients with nasopharyngeal carcinoma: A U-shaped distribution suggests low dose supplement. Clin Nutr 2021;40(4):2293-2300. PubMed
  31. Tanigawa J, Nabatame S, Tominaga K, et al. High-dose pyridoxine treatment for inherited glycosylphosphatidylinositol deficiency. Brain Dev 2021;43(6):680-687. PubMed
  32. Committee on Practice Bulletins-Obstetrics. ACOG Practice Bulletin No. 189: Nausea And Vomiting Of Pregnancy. Obstet Gynecol. 2018;131(1):e15-e30. PubMed

See these in context on the Vitamin B6 monograph →

Vitamin D 26 references
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  2. Tatro DS, ed. Drug Interactions Facts. Facts and Comparisons Inc., St. Louis, MO. 1999.
  3. 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
  4. Bar-Or D, Yoel G. Calcium and calciferol antagonize effect of verapamil in atrial fibrillation. Br Med J 1981;282:1585-6.
  5. 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.
  6. Crowe M, Wollner L, Griffiths RA. Hypercalcemia following vitamin D and thiazide therapy in the elderly. Practitioner 1984;228:312-3.
  7. Parfitt AM. Thiazide-induced hypercalcemia in vitamin D-treated hypoparathyroidism. Ann Intern Med 1972;77:557-63. PubMed
  8. Thiazide diuretics and the risk of osteoporosis. Pharmacist's Letter/Prescriber's Letter 2003;19(11):191105.
  9. Moon J. The role of vitamin D in toxic metal absorption. J Am Coll Nutr 1994;13:559-64.
  10. 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.
  11. Adler AJ, Berlyne GM. Duodenal aluminum absorption in the rat: effect of vitamin D. Am J Physiol 1985;249:G209-13. PubMed
  12. 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
  13. 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
  14. 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
  15. 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
  16. 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
  17. 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
  18. 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
  19. Weiner M, Epstein FH. Signs and symptoms of electrolyte disorders. Yale J Biol Med. 1970;43(2):76-109.
  20. 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
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  22. 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.
  23. 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
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  26. 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

See these in context on the Vitamin D monograph →

Zinc 88 references
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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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