Heme Iron SAP Ingredients & Drug Interactions
by NFH
What is this page for?
First and foremost: checking Heme Iron SAP 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
Heme Iron SAP is a dietary supplement by NFH with 4 active ingredients. Its ingredients are commonly taken for treating or preventing b12 deficiency, pernicious anemia, low energy and fatigue.Based on those ingredients, 301 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Vitamin C, Iron, Vitamin B12. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
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HelloPharmacist Scorecard of Heme Iron SAP by NFH
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
Heme Iron SAP contains four active ingredients: vitamin B12, vitamin C, folate, and iron (heme iron). Vitamin B12 supports red blood cell formation and nerve function; vitamin C aids iron absorption and acts as an antioxidant; folate is essential for cell division and DNA synthesis; and iron carries oxygen in your blood and builds hemoglobin, the protein that makes red blood cells work.
The product also contains inactive ingredients—vegetable magnesium stearate, microcrystalline cellulose, silicon dioxide, and a vegetable capsule—which are fillers and binding materials that help form and deliver the capsule.
Does it work?
Strong evidence
Vitamin B12 in this product is effective for B12 deficiency and for Imerslund-Grasbeck disease (a rare condition affecting B12 absorption), and is likely effective for cyanide poisoning. It's possibly effective for canker sores and postherpetic neuralgia (nerve pain after shingles).
Vitamin C is effective for vitamin C deficiency and is possibly effective for anemia of chronic disease, atrial fibrillation, cataracts, and exercise-induced respiratory infections. Iron is effective for iron deficiency anemia, anemia of chronic disease, and pregnancy-related iron deficiency, and is possibly effective for certain types of heart failure.
We have no effectiveness data on file for folate in this product.
How safe is it?
Well-documented data
Vitamin B12 is generally very safe and is considered safe in pregnancy and while breastfeeding at normal recommended amounts. It's well tolerated orally, though injection site reactions can occur if given by injection, and rare allergic reactions (rash, itching, hives) have been reported.
Vitamin C is generally well tolerated at normal doses but can cause abdominal cramps, heartburn, nausea, vomiting, and kidney stones at very high doses—adverse effects are more likely above 2 grams daily. The safety data advises caution with high-dose supplements in pregnancy and while breastfeeding; normal prenatal amounts are fine.
Iron is generally well tolerated at recommended doses but commonly causes abdominal pain, constipation, diarrhea, nausea, or vomiting. The safety data advises that iron is often recommended in pregnancy but your prenatal care provider should guide your dose, and while breastfeeding check with your provider about appropriate amounts.
Excess iron can be toxic and supplements should only be used when there is a real need.
Meds to double-check
Moderate interaction found
Before taking this product, double-check with your doctor or pharmacist if you take oral contraceptives or hormone replacement therapy (vitamin C can increase estrogen levels), blood thinners like warfarin, chemotherapy drugs, thyroid medication (levothyroxine), diabetes medications like metformin, blood pressure medications like methyldopa, antibiotics (quinolones or tetracyclines), bisphosphonates for bone health, or Parkinson's medication (levodopa). All of these have Moderate interactions with ingredients in this product, and timing or dose adjustments may help.
The bottom line
Scorecard at a glanceFully disclosed formula with clinical evidence supporting its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.
This product may be right for you if you're dealing with iron deficiency anemia, need B12 and folate support, or want vitamin C for general health—but it's important to check whether it interacts with any medications you take first. If you're on birth control, a blood thinner, thyroid medication, an antibiotic, or a blood pressure or diabetes medication, run this product through the checker on this page before starting.
Talk it over with your doctor or pharmacist to make sure it fits your health picture.
Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI
Assessment coverage: 3 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Mar 22, 2023.
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 Heme Iron SAP, straight from the product label.
| Brand | NFH |
|---|---|
| Barcode (UPC) | 856711111241 |
| Net contents | 60 Capsule(s) |
| Market status | On market |
| Date entered into DSLD | Mar 22, 2023 |
| DSLD ID | 275881 |
| Product type | Other Combinations |
| Supplement form | Capsule |
| Dietary claims / uses | All Other, Structure/Function |
| Intended target group(s) | Adult (18 - 50 Years), Gluten Free, Dairy Free, Sugar 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 Heme Iron SAP by NFH, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| Vitamin B12 | 1000 mcg | 41667% |
| Vitamin C | 270 mg | 300% |
| Folate | 1700 mcg DFE | 250% |
| Iron | 33 mg | 183% |
Other ingredients: Vegetable Magnesium Stearate, Microcrystalline Cellulose, Silicon Dioxide, Vegetable 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.
Formulation
Heme Iron SAP helps to form red blood cells and helps in their proper function. Heme Iron SAP is a factor in the maintenance of good health.
All ingredients listed for this product lot number have been tested by a third-party laboratory for identity, potency, and purity.
Contains no: Gluten, soy, wheat, corn, eggs, dairy, yeast, citrus, preservatives, artificial flavor or color, starch, or sugar.
This product is non-GMO.
Colour, size and smell may vary from one lot to another.
Superior absorption and bioavailability
Made in Canada
Suggested/Recommended/Usage/Directions
Directions for use: Adults: Take 3 capsules once daily with a full glass of water, with or without food, or as directed by your healthcare practitioner. Do not lie down for 30 minutes after taking this product. Consult a healthcare practitioner for use beyond 7 weeks. Consult a healthcare practitioner to monitor blood iron content.
Precautions
Cautions and warnings: Consult a healthcare practitioner prior to use if you have a peptic ulcer, regional enteritis, or ulcerative colitis; or if you are using methyldopa or other iron-containing products; or if you are pregnant, breast-feeding, or have hemochromatosis, other types of anemia, repeated blood transfusions, or stomach / intestinal problems.
Constipation, diarrhea, nausea, upset stomach and abdominal cramping may occur. Iron supplements can decrease the absorption of certain drugs and doses of such medications should be spaced as far as possible. This product may interfere with certain laboratory tests (testing for blood in stool), possibly causing false test results; make sure laboratory personnel and all doctors know you are taking this product.
Do not use if seal is broken.
Keep out of reach of children.
Warning: Accidental overdose of iron-containing products is a leading cause of fatal poisoning in children under 6. Keep this product out of the reach of children.
In case of accidental overdose, call your physician or poison control center immediately.
FDA Disclaimer Statement
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
General Statements
NPN 80068013
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
Heme Iron SAP by NFH 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 Heme Iron SAP by NFH
These are the 4 active ingredients this product is made of. Select any to open its full monograph.
Serving size3 Capsule(s) Dosage formCapsule Servings per container20 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 B12
Interacts with20 drugs
Vitamin B12 (cobalamin) is an essential nutrient your body needs to make red blood cells, keep nerves healthy, and support DNA. Supplements are very h...
Vitamin B12 monograph & interactionsVitamin C
Interacts with207 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 im...
Vitamin C monograph & interactionsFolate
Iron
Interacts with80 drugs
Iron is an essential mineral your body needs to make hemoglobin and carry oxygen in the blood. Supplements are mainly useful for treating or preventin...
Iron monograph & interactionsOther (inactive) ingredients: Vegetable Magnesium Stearate, Microcrystalline Cellulose, Silicon Dioxide, Vegetable Capsule. These complete the product’s ingredient list but are not active constituents.
Heme Iron SAP by NFH Drug Interactions
HelloPharmacist Interaction Report
Heme Iron SAP by NFH interacts with medications through its vitamin B12, vitamin C, and iron content.
The most serious documented interaction is Moderate in severity: vitamin C may increase blood estrogen levels by up to 55% when taken with oral contraceptives or hormone replacement therapy, potentially affecting how well these birth control or hormone treatments work.
Read the full breakdown — every affected drug type, severity by severity
Vitamin C also has Moderate interactions with chemotherapy drugs (alkylating agents and antitumor antibiotics), where its antioxidant effects might reduce drug effectiveness, and with blood thinners like warfarin, where high doses of vitamin C can lower warfarin levels and reduce clotting control. Additionally, vitamin C can increase aluminum absorption from aluminum-containing compounds and affect how your body absorbs levothyroxine (thyroid medication), fluphenazine (an antipsychotic), indinavir (an HIV medication), and a few others.
Iron carries Moderate interactions with several drug classes: it reduces absorption of levodopa (Parkinson's medication), quinolone antibiotics, bisphosphonates (bone medications), methyldopa (blood pressure medication), tetracycline antibiotics, levothyroxine, mycophenolate mofetil (an immunosuppressant), and penicillamine (a copper-binding agent). These interactions happen because iron forms insoluble complexes in your gut that prevent the medication from being absorbed properly—separating doses by at least 2 hours usually helps.
Vitamin B12 has one Moderate interaction: metformin (a common diabetes medication) can lower B12 levels over time because it interferes with how your digestive system absorbs B12. We could not check folate for interactions because no data is on file for it.
Altogether, these interactions span 301 individual medications. Use the medication checker on this page to see if any of your specific prescriptions are affected.
Check your own medications below · Editorial policy · How we use AI
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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 Heme Iron SAP interact with 301 drugs. Click any drug to see the details.
3 of the 4 ingredients in Heme Iron SAP interact with drugs. Each result below shows which ingredient is responsible. Vitamin C Iron Vitamin B12
Chlorothiazide, MethyldopaAldochlor, Aldoclor 150, Aldoclor 250
How Chlorothiazide, Methyldopa interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
IronMethyldopa (aldomet) Moderate
Interaction Summary
Iron might decrease methyldopa levels by reducing its absorption.
Read the full Iron + Chlorothiazide, Methyldopa interactionChlortetracyclineAureomycin
How Chlortetracycline interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
IronTetracycline Antibiotics Moderate
Interaction Summary
Iron might decrease levels of tetracycline antibiotics by reducing their absorption.
Read the full Iron + Chlortetracycline interactionCinoxacinCinobac
How Cinoxacin interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
IronQuinolone Antibiotics Moderate
Interaction Summary
Iron might decrease levels of quinolone antibiotics by reducing their absorption.
Read the full Iron + Cinoxacin interactionCiprofloxacinCiloxan, Cipro, Cipro IV, Cipro XR, Ciprobay, Otiprio
How Ciprofloxacin interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
IronQuinolone Antibiotics Moderate
Interaction Summary
Iron might decrease levels of quinolone antibiotics by reducing their absorption.
Read the full Iron + Ciprofloxacin interactionCisplatinPlatinol-AQ
How Cisplatin interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAlkylating Agents Moderate
Interaction Summary
Theoretically, antioxidant effects of vitamin C might reduce the effectiveness of alkylating agents.
Read the full Vitamin C + Cisplatin interactionClinafloxacinClinafloxacin
How Clinafloxacin interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
IronQuinolone Antibiotics Moderate
Interaction Summary
Iron might decrease levels of quinolone antibiotics by reducing their absorption.
Read the full Iron + Clinafloxacin interactionCobicistat, Elvitegravir, Emtricitabine, Tenofovir Alafenamide FumarateGenvoya
How Cobicistat, Elvitegravir, Emtricitabine, Tenofovir Alafenamide Fumarate interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
IronBictegravir/emtricitabine/tenofovir Alafenamide (biktarvy) Moderate
Interaction Summary
Iron might decrease levels of bictegravir/emtricitabine/tenofovir alafenamide by reducing its absorption when taken in a fasting state.
Read the full Iron + Cobicistat, Elvitegravir, Emtricitabine, Tenofovir Alafenamide Fumarate interactionConjugated EstrogensCenestin, Enjuvia, Premarin, Premarin Vaginal Cream
How Conjugated Estrogens interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CEstrogens Moderate
Interaction Summary
Vitamin C might increase blood levels of estrogens.
Read the full Vitamin C + Conjugated Estrogens interactionConjugated Estrogens, Medroxyprogesterone AcetatePremplus, Prempro
How Conjugated Estrogens, Medroxyprogesterone Acetate interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CEstrogens Moderate
Interaction Summary
Vitamin C might increase blood levels of estrogens.
Read the full Vitamin C + Conjugated Estrogens, Medroxyprogesterone Acetate interactionConjugated Estrogens, MeprobamatePMB 200, PMB 400
How Conjugated Estrogens, Meprobamate interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CEstrogens Moderate
Interaction Summary
Vitamin C might increase blood levels of estrogens.
Read the full Vitamin C + Conjugated Estrogens, Meprobamate interactionConjugated Estrogens, MethyltestosteronePremarin with Methyltestosterone
How Conjugated Estrogens, Methyltestosterone interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CEstrogens Moderate
Interaction Summary
Vitamin C might increase blood levels of estrogens.
Read the full Vitamin C + Conjugated Estrogens, Methyltestosterone interactionCyclophosphamideCytoxan, Neosar
How Cyclophosphamide interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAlkylating Agents Moderate
Interaction Summary
Theoretically, antioxidant effects of vitamin C might reduce the effectiveness of alkylating agents.
Read the full Vitamin C + Cyclophosphamide interactionCyproterone Acetate, Ethinyl EstradiolDiane-35, Dianette
How Cyproterone Acetate, Ethinyl Estradiol interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CEstrogens Moderate
Interaction Summary
Vitamin C might increase blood levels of estrogens.
Read the full Vitamin C + Cyproterone Acetate, Ethinyl Estradiol interactionDacarbazineDTIC-Dome
How Dacarbazine interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAlkylating Agents Moderate
Interaction Summary
Theoretically, antioxidant effects of vitamin C might reduce the effectiveness of alkylating agents.
Read the full Vitamin C + Dacarbazine interactionDactinomycinCosmegan, Cosmegen
How Dactinomycin interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAntitumor Antibiotics Moderate
Interaction Summary
Theoretically, the antioxidant effects of vitamin C might reduce the effectiveness of antitumor antibiotics.
Read the full Vitamin C + Dactinomycin interactionDarunavir, Cobicistat, Emtricitabine, Tenofovir AlafenamideSymtuza
How Darunavir, Cobicistat, Emtricitabine, Tenofovir Alafenamide interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
IronBictegravir/emtricitabine/tenofovir Alafenamide (biktarvy) Moderate
Interaction Summary
Iron might decrease levels of bictegravir/emtricitabine/tenofovir alafenamide by reducing its absorption when taken in a fasting state.
Read the full Iron + Darunavir, Cobicistat, Emtricitabine, Tenofovir Alafenamide interactionDaunorubicin CitrateDaunoXome
How Daunorubicin Citrate interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAntitumor Antibiotics Moderate
Interaction Summary
Theoretically, the antioxidant effects of vitamin C might reduce the effectiveness of antitumor antibiotics.
Read the full Vitamin C + Daunorubicin Citrate interactionDaunorubicin HydrochlorideCerubidine
How Daunorubicin Hydrochloride interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAntitumor Antibiotics Moderate
Interaction Summary
Theoretically, the antioxidant effects of vitamin C might reduce the effectiveness of antitumor antibiotics.
Read the full Vitamin C + Daunorubicin Hydrochloride interactionDaunorubicin, CytarabineVyxeos
How Daunorubicin, Cytarabine interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAntitumor Antibiotics Moderate
Interaction Summary
Theoretically, the antioxidant effects of vitamin C might reduce the effectiveness of antitumor antibiotics.
Read the full Vitamin C + Daunorubicin, Cytarabine interactionDemeclocyclineDeclomycin
How Demeclocycline interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
IronTetracycline Antibiotics Moderate
Interaction Summary
Iron might decrease levels of tetracycline antibiotics by reducing their absorption.
Read the full Iron + Demeclocycline interactionDenosumabProlia, XGEVA
How Denosumab interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
IronDenosumab (prolia, Others) Moderate
Interaction Summary
Administration of intravenous iron within one month of denosumab administration might increase the risk of severe hypophosphatemia and hypocalcemia.
Read the full Iron + Denosumab interactionDesogestrel, Ethinyl EstradiolDesogen, Marvelon, Marvelon 21, Marvelon 28, Mircette, Ortho-Cept +2 more
How Desogestrel, Ethinyl Estradiol interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CEstrogens Moderate
Interaction Summary
Vitamin C might increase blood levels of estrogens.
Read the full Vitamin C + Desogestrel, Ethinyl Estradiol interactionDihydroxyaluminum Sodium CarbonateRolaids
How Dihydroxyaluminum Sodium Carbonate interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAluminum Moderate
Interaction Summary
Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.
Read the full Vitamin C + Dihydroxyaluminum Sodium Carbonate interactionDolutegravirTivicay
How Dolutegravir interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
IronDolutegravir (tivicay) Moderate
Interaction Summary
Iron might decrease dolutegravir levels by reducing its absorption.
Read the full Iron + Dolutegravir interactionDolutegravir, Emtricitabine, Tenofovir AlafenamideDolutegravir, Emtricitabine, Tenofovir Alafenamide
How Dolutegravir, Emtricitabine, Tenofovir Alafenamide interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
IronDolutegravir (tivicay), Bictegravir/emtricitabine/tenofovir Alafenamide (biktarvy) Moderate
Interaction Summary
Iron might decrease dolutegravir levels by reducing its absorption.
Read the full Iron + Dolutegravir, Emtricitabine, Tenofovir Alafenamide interactionDolutegravir, RilpivirineJuluca
How Dolutegravir, Rilpivirine interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
IronDolutegravir (tivicay) Moderate
Interaction Summary
Iron might decrease dolutegravir levels by reducing its absorption.
Read the full Iron + Dolutegravir, Rilpivirine interactionDoripenemDoribax
How Doripenem interacts with Heme Iron SAP — through 2 ingredients. Tap an ingredient for the detail:
IronQuinolone Antibiotics, Tetracycline Antibiotics Moderate
Interaction Summary
Iron might decrease levels of quinolone antibiotics by reducing their absorption.
Read the full Iron + Doripenem interactionVitamin CAntitumor Antibiotics Moderate
Interaction Summary
Theoretically, the antioxidant effects of vitamin C might reduce the effectiveness of antitumor antibiotics.
Read the full Vitamin C + Doripenem interactionDoxorubicinAdriamycin, Caelyx, Doxil, Myocet, Rubex
How Doxorubicin interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
Vitamin CAntitumor Antibiotics Moderate
Interaction Summary
Theoretically, the antioxidant effects of vitamin C might reduce the effectiveness of antitumor antibiotics.
Read the full Vitamin C + Doxorubicin interactionDoxycyclineDoryx, Doxy, Doxy-D, Doxycin, Doxycycline Injection, Doxylin +6 more
How Doxycycline interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
IronTetracycline Antibiotics Moderate
Interaction Summary
Iron might decrease levels of tetracycline antibiotics by reducing their absorption.
Read the full Iron + Doxycycline interactionDoxycycline HyclateActiclate, Acticlate Cap, Lymepak
How Doxycycline Hyclate interacts with Heme Iron SAP — through 1 ingredient. Tap an ingredient for the detail:
IronTetracycline Antibiotics Moderate
Interaction Summary
Iron might decrease levels of tetracycline antibiotics by reducing their absorption.
Read the full Iron + Doxycycline Hyclate interactionEach ingredient & the kinds of drugs it affects
For each ingredient in Heme Iron SAP 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 C
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Iron
Bictegravir/Emtricitabine/Tenofovir Alafenamide (Biktarvy)
Iron might decrease levels of bictegravir/emtricitabine/tenofovir alafenamide by reducing its absorption when taken in a fasting state.
Advise patients that bictegravir/emtricitabine/tenofovir alafenamide and iron can be taken together if taken with food. However, if taken on an empty stomach, bictegravir/emtricitabine/tenofovir alafenamide should not be taken with, or 2 hours after, iron containing products.
Bisphosphonates
Iron reduces the absorption of bisphosphonates.
Advise patients that doses of bisphosphonates should be separated by at least two hours from doses of all other medications, including supplements such as iron. Divalent cations, including iron, can decrease absorption of bisphosphonates by forming insoluble complexes in the gastrointestinal tract.
Denosumab (Prolia, Others)
Administration of intravenous iron within one month of denosumab administration might increase the risk of severe hypophosphatemia and hypocalcemia.
A case of severe hypocalcemia (albumin corrected calcium 6.88 mg/dL, ionized calcium 3.68 mg/dL) and hypophosphatemia (<0.5 mg/dL) with respiratory acidosis, QT interval prolongation, and nonsustained ventricular tachycardia was reported in a 76-year-old male who had received an iron polymaltose infusion within 2 weeks of a subcutaneous injection of denosumab. Serum parathyroid hormone was also elevated (348 pg/mL). Subsequent iron infusions with iron polymaltose and ferric carboxymaltose were followed by transient hypophosphatemia, but without hypocalcemia. Additionally, a literature review describes 6 additional cases of hypophosphatemia and hypocalcemia in patients 52-92 years of age who had been administered intravenous iron as either ferric carboxymaltose or iron polymaltose and subcutaneous denosumab within 1-4 weeks of each other.
Dolutegravir (Tivicay)
Iron might decrease dolutegravir levels by reducing its absorption.
Advise patients to take dolutegravir at least 2 hours before or 6 hours after taking iron. Pharmacokinetic research shows that iron can decrease the absorption of dolutegravir from the gastrointestinal tract through chelation. When taken under fasting conditions, a single dose of ferrous fumarate 324 mg orally along with dolutegravir 50 mg reduces overall exposure to dolutegravir by 54%.
Integrase Inhibitors
Theoretically, taking iron along with integrase inhibitors might decrease the levels and clinical effects of these drugs.
Iron is a divalent cation. There is concern that iron may decrease the absorption of integrase inhibitors from the gastrointestinal tract through chelation. One pharmacokinetic study shows that iron can decrease blood levels of the specific integrase inhibitor dolutegravir through chelation. Also, other pharmacokinetic research shows that other divalent cations such as calcium can decrease the absorption and levels of some integrase inhibitors through chelation.
Levodopa
Iron might decrease levodopa levels by reducing its absorption.
Advise patients to separate doses of levodopa and iron as much as possible. There is some evidence in healthy people that iron forms chelates with levodopa, reducing the amount of levodopa absorbed by around 50%. The clinical significance of this hasn't been determined.
Levothyroxine (Synthroid, Others)
Iron might decrease levothyroxine levels by reducing its absorption.
Advise patients to separate levothyroxine and iron doses by at least 2 hours. Iron can decrease the absorption and efficacy of levothyroxine by forming insoluble complexes in the gastrointestinal tract.
Methyldopa (Aldomet)
Iron might decrease methyldopa levels by reducing its absorption.
Advise patients to separate methyldopa and iron doses by at least 2 hours. Iron can decrease the absorption of methyldopa from the gastrointestinal tract through chelation, resulting in increases in blood pressure.
Mycophenolate Mofetil (Cellcept)
Theoretically, iron might decrease mycophenolate mofetil levels by reducing its absorption.
Advise patients to take iron 4-6 hours before, or 2 hours after, mycophenolate mofetil. It has been suggested that a decrease of absorption is possible, probably by forming nonabsorbable chelates. However, mycophenolate pharmacokinetics are not affected by iron supplementation in available clinical research.
Penicillamine (Cuprimine, Depen)
Iron might decrease penicillamine levels by reducing its absorption.
Advise patients to separate penicillamine and iron doses by at least 2 hours. Oral iron supplements can reduce absorption of penicillamine by 30% to 70%, probably due to chelate formation. In people with Wilson's disease, this interaction has led to reduced efficacy of penicillamine.
Quinolone Antibiotics
Iron might decrease levels of quinolone antibiotics by reducing their absorption.
Advise patients to separate quinolone antibiotics and iron doses by at least 2 hours. Iron decreases the absorption of quinolones due to formation of insoluble complexes in the gastrointestinal tract.
Tetracycline Antibiotics
Iron might decrease levels of tetracycline antibiotics by reducing their absorption.
Advise patients to take iron at least 2 hours before or 4 hours after tetracycline antibiotics. Concomitant use can decrease absorption of tetracycline antibiotics from the gastrointestinal tract by 50% to 90%.
Chloramphenicol
Theoretically, taking chloramphenicol with iron might reduce the response to iron therapy in iron deficiency anemia.
Chloramphenicol interferes with erythrocyte maturation. However, since chloramphenicol isn't usually taken for prolonged periods, this isn't likely to be clinically significant.
Vitamin B12
Metformin (Glucophage)
Metformin, a common medication used to manage type 2 diabetes, has been associated with lower vitamin B12 levels in some individuals. Prolonged use of metformin can interfere with the absorption of B12 in the digestive system, potentially leading to a deficiency in this essential vitamin.
Brand information
Manufacturer and brand details for Heme Iron SAP, from the product label.
NFH
See all NFH products- Name
- NFH - Nutritional Fundamentals for Health, Inc.
- Street Address
- 351 Rue Joseph-Carrier
- City
- Vaudreuil
- State
- QC
- ZipCode
- J7V 5V5
- Phone Number
- 1 866 510-3123
- Web Address
- nfh.ca
Heme Iron SAP by NFH: Common Questions
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The Full Monographs Behind Heme Iron SAP’s Ingredients
Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.
Vitamin B12
Interacts with 20 drugsVitamin B12 (cobalamin) is an essential nutrient your body needs to make red blood cells, keep nerves healthy, and support DNA. Supplements are very helpful for people who are deficient — su...
Read the full Vitamin B12 monograph → Herb & supplement monographVitamin C
Interacts with 207 drugsVitamin 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 → Herb & supplement monographIron
Interacts with 80 drugsIron is an essential mineral your body needs to make hemoglobin and carry oxygen in the blood. Supplements are mainly useful for treating or preventing iron deficiency and iron-deficiency an...
Read the full Iron monograph →Sources & How We Checked
Heme Iron SAP'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 153 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 B12 30 references
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- Pegalajar-García MD, Cebolla-Verdugo M, Prados-Carmona Á, Llamas-Segura C, Navarro-Triviño FJ. Systemic allergic dermatitis to cobalt present in cyanocobalamin supplementation. Contact Dermatitis 2023;89(3):203-205. PubMed
Vitamin C 51 references
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Iron 72 references
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