| Ingredients | Amount Per Serving |
|---|---|
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(Ascorbic Acid)
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1000 mg |
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(from Lemons, Limes, Oranges, & Tangerines)
(Citrus Bioflavonoid Complex (Form: from Lemons, Oranges, Limes, & Tangerines) )
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100 mg |
Below is general information about the effectiveness of the known ingredients contained in the product Vitamin C with Bioflavonoids. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
Below is general information about the safety of the known ingredients contained in the product Vitamin C with Bioflavonoids. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
LIKELY SAFE ...when used in amounts commonly found in foods. Lemon has Generally Recognized as Safe (GRAS) status in the US (4912).
POSSIBLY SAFE ...when inhaled in amounts used for aromatherapy, short-term. Lemon essential oil has been used with apparent safety as aromatherapy for up to 2 weeks in clinical research (93475,98128,98129). There is insufficient reliable information available about the safety of lemon when used topically, or when used orally or intranasally in medicinal amounts.
PREGNANCY AND LACTATION:
Insufficient reliable information available.
Avoid using in amounts greater than those typically found in foods.
LIKELY SAFE ...when used orally in amounts commonly found in foods. Lime has Generally Recognized As Safe status (GRAS) for use in foods in the US (4912).
POSSIBLY UNSAFE ...when used topically. Lime oil and lime juice contain photosensitizing constituents (12,11019,40894,59925,59928,100125,100126,100129). ...when used intravaginally. Lime juice has caused mild to moderate adverse effects in women using lime juice-soaked tampons or as a douche, especially in concentrations of 20% or more (100127,100128). There is insufficient reliable information available about the safety of lime when used orally in medicinal amounts.
PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using in amounts greater than those typically found in foods.
LIKELY SAFE ...when sweet orange juice or fruit is used orally in amounts commonly found in foods (1310,3340,15171,92309,114401).
POSSIBLY SAFE ...when the essential oil of sweet orange is inhaled as aromatherapy, short-term (35735,58060,90505,105455). There is insufficient reliable information available about the safety of sweet orange peel when used orally.
CHILDREN: LIKELY SAFE
when sweet orange juice or fruit is used orally in amounts commonly found in foods.
CHILDREN: POSSIBLY UNSAFE
when the sweet orange peel is used orally in excessive amounts.
There have been reports of intestinal colic, convulsions, and death in children given large amounts of sweet orange peel (11).
PREGNANCY AND LACTATION: LIKELY SAFE
when sweet orange juice or fruit is used orally in amounts commonly found in foods (1310,3340).
LIKELY SAFE ...when used orally in amounts commonly found in foods. Tangerine has Generally Recognized as Safe (GRAS) status in the US (4912). There is insufficient reliable information available about the safety of tangerine when used orally or topically as a medicine.
PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.
LIKELY SAFE ...when used orally, topically, intramuscularly, or intravenously and appropriately. Vitamin C is safe when taken orally in doses below the tolerable upper intake level (UL). Tell patients not to exceed the UL of 2000 mg daily (1959,4713,4714,4844). ...when used intravenously or intramuscularly and appropriately. Injectable vitamin C is an FDA-approved prescription product (15).
POSSIBLY UNSAFE ...when used orally in excessive doses. Doses greater than the tolerable upper intake level (UL) of 2000 mg daily can significantly increase the risk of adverse effects such as osmotic diarrhea and gastrointestinal upset (4844).
CHILDREN: LIKELY SAFE
when used orally and appropriately (4844,10352,14443).
CHILDREN: POSSIBLY UNSAFE
when used orally in excessive amounts.
Tell patients not to use doses above the tolerable upper intake level (UL) of 400 mg daily for children ages 1 to 3 years, 650 mg daily for children 4 to 8 years, 1200 mg daily for children 9 to 13 years, and 1800 mg daily for adolescents 14 to 18 years. Higher doses can cause osmotic diarrhea and gastrointestinal upset (4844).
PREGNANCY AND LACTATION: LIKELY SAFE
when used orally and appropriately (4844).
PREGNANCY AND LACTATION: POSSIBLY UNSAFE
when used orally in excessive doses.
Tell patients over age 19 not to use doses exceeding the UL of 2000 mg daily when pregnant or breast-feeding and for those 14-18 years of age not to use doses exceeding 1800 mg daily when pregnant or breast-feeding. Higher doses can cause osmotic diarrhea and gastrointestinal upset. Large doses of vitamin C during pregnancy can also cause newborn scurvy (4844); avoid using.
Below is general information about the interactions of the known ingredients contained in the product Vitamin C with Bioflavonoids. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
Theoretically, taking itraconazole capsules or tablets with a beverage containing lemon might increase the levels and clinical effects of itraconazole.
 Details
In one case report, dissolving itraconazole tablets in a small amount of specific beverages containing lemon prior to administration increased the level of itraconazole in a lung transplant patient. In this case, the increased bioavailability was desirable and was likely due to improved tablet dissolution in the acidic beverage (110781).
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Lime juice inhibits cytochrome P450 3A4, causing increased drug levels and potentially increasing the risk of adverse effects (11976). Some drugs metabolized by CYP3A4 that might be affected are some benzodiazepines such as alprazolam (Xanax), diazepam (Valium), midazolam (Versed), triazolam (Halcion); calcium channel blockers such as amlodipine (Norvasc), diltiazem (Cardizem, Dilacor, others), felodipine (Plendil), verapamil (Calan, Verelan, others); cyclosporine (Neoral, Sandimmune); some HIV antivirals such as indinavir (Crixivan), ritonavir (Norvir), saquinavir (Fortovase, Invirase); some HMG CoA reductase inhibitors such as atorvastatin (Lipitor), lovastatin (Mevacor); some macrolide antibiotics such as erythromycin and clarithromycin (Biaxin); quinidine; and many others.
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Theoretically, concomitant use of lime oil with photosensitizing drugs may increase the risk of phototoxicity (11019).
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Consuming sweet orange with celiprolol can decrease oral absorption of celiprolol.
Details
A pharmacokinetic study in healthy volunteers shows that celiprolol levels, after a single dose of 100 mg, are decreased by up to 90% in people who drink sweet orange juice 200 mL three times daily. It's not known if lower consumption of sweet orange juice will have the same effect. Theoretically, this occurs due to short-term inhibition of organic anion transporting polypeptide (OATP) (12115,17603,17604). Recommend separating drug administration and consumption of sweet orange by at least 4 hours (17603,17604).
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Consuming sweet orange juice with fexofenadine can decrease oral absorption of fexofenadine.
Details
Clinical research shows that coadministration of sweet orange juice 1200 mL decreases bioavailability of fexofenadine by about 72% (7046,17604). In an animal model, sweet orange juice decreased bioavailability of fexofenadine by 31% (17605). Fexofenadine manufacturer data indicates that concomitant administration of sweet orange juice and fexofenadine results in larger wheal and flare sizes in research models. This suggests that sweet orange reduces the clinical response to fexofenadine (17603). Theoretically, this occurs due to short-term inhibition of organic anion transporting polypeptide (OATP) (7046). Recommend separating drug administration and consumption of sweet orange by at least 4 hours (17603,17604).
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Consuming sweet orange juice with ivermectin can decrease the oral absorption of ivermectin.
Details
A pharmacokinetic study in healthy volunteers shows that taking ivermectin orally with sweet orange juice 750 mL over 4 hours reduces the bioavailability of ivermectin. This effect does not seem to be related to effects on P-glycoprotein. The effect on ivermectin is more pronounced in males compared to females (12154).
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Consuming sweet orange juice can decrease oral absorption of OATP substrates. Separate administration by at least 4 hours.
Details
Clinical research shows that consuming sweet orange juice inhibits OATP, which reduces bioavailability of oral drugs that are substrates of OATP (17603,17604). For example, sweet orange juice decreases bioavailability of fexofenadine, a substrate of OATP, by about 72% and of celiprolol, another OATP substrate, by up to 90% (7046,12115). Since sweet orange juice seems to affect OATP for a short time, recommend separating drug administration and consumption of sweet orange juice by at least 4 hours (17603,17604).
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Sweet orange juice seems to modulate P-glycoprotein (P-gp), which might affect the blood levels of P-gp substrates.
Details
Animal and in vitro research suggest that orange juice extract inhibits drug efflux by P-gp, increasing absorption and levels of P-gp substrates (12116,15327). In contrast, pharmacokinetic research in humans shows that drinking large amounts of sweet orange juice decreases absorption and levels of the P-gp substrate celiprolol. This suggests that orange juice actually induces drug efflux by P-gp or affects drug levels by another mechanism such as inhibiting the gut drug transporter called organic anion transporting polypeptide (OATP) (7046,12115). Until more is known, sweet orange juice should be used cautiously in people taking P-gp substrates.
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Consuming sweet orange juice with pravastatin can increase the absorption of pravastatin.
Details
A small pharmacokinetic study in healthy volunteers shows that consuming sweet orange juice 800 mL over 3 hours, including before, during, and after taking pravastatin 10 mg, increases pravastatin levels by about 149%, without affecting pravastatin elimination. Theoretically this effect might be due to modulation of organic anion transporting polypeptides (OATPs) by sweet orange juice (14348). Sweet orange juice does not seem to affect simvastatin levels, but it is not known if sweet orange affects any of the other statins.
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Calcium-fortified sweet orange juice might reduce quinolone absorption.
Details
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In vitro, tangeretin, a constituent of tangerine, induces a 52% increase in the metabolism of midazolam by cytochrome P450 3A4 (CYP3A4) (28609). This suggests that tangeretin may stimulate CYP3A4 activity. However, in humans, drinking tangerine juice 200 mL slightly delayed the absorption, but did not affect the metabolism, of midazolam, a CYP3A4 substrate (28609). Theoretically, tangerine juice might increase CYP3A4 activity and decrease levels of drugs metabolized by this enzyme. However, this effect is unlikely.
Details
Some drugs metabolized by CYP3A4 include amitriptyline (Elavil), amiodarone (Cordarone), citalopram (Celexa), felodipine (Plendil), lansoprazole (Prevacid), ondansetron (Zofran), prednisone (Deltasone, Orasone), sertraline (Zoloft), sibutramine (Meridia), and many others.
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In vitro, tangeretin, a constituent of tangerine, appears to increase the metabolism of midazolam in human liver microsomes by up to 52% (28609). However, in humans, drinking tangerine juice 200 mL slightly delayed the absorption, but did not affect the metabolism, of midazolam (28609). Theoretically, tangerine juice might increase the metabolism and reduce the effects of midazolam. However, this effect is unlikely.
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High-dose vitamin C might slightly prolong the clearance of acetaminophen.
Details
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 (6451). This effect is not likely to be clinically significant.
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Theoretically, antioxidant effects of vitamin C might reduce the effectiveness of alkylating agents.
Details
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 (391). 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 (14012,14013). More evidence is needed to determine what effect, if any, antioxidants such as vitamin C have on chemotherapy.
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Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.
Details
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 (10549,10550,10551,21556). In people with normal renal function, urinary excretion of aluminum will likely increase, making aluminum retention and toxicity unlikely (10549). 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.
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Theoretically, the antioxidant effects of vitamin C might reduce the effectiveness of antitumor antibiotics.
Details
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 (391). 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 (14012,14013). More evidence is needed to determine what effects, if any, antioxidants such as vitamin C have on chemotherapy.
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Acidification of the urine by vitamin C might increase aspirin levels.
Details
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 (3046). However, short-term use of up to 6 grams daily of vitamin C does not seem to affect urinary pH or salicylate excretion (10588,10589), suggesting this interaction is not clinically significant.
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Acidification of the urine by vitamin C might increase choline magnesium trisalicylate levels.
Details
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 (3046,4531). However, short-term use of up to 6 grams daily of vitamin C does not seem to affect urinary pH or salicylate excretion (10588,10589), suggesting this interaction probably is not clinically significant.
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Vitamin C might increase blood levels of estrogens.
Details
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 (129,130,11161). 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 (129,11161). 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 (11161). Monitor these patients for estrogen-related side effects.
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Theoretically, vitamin C might decrease levels of fluphenazine.
Details
In one patient there was a clinically significant decrease in fluphenazine levels when vitamin C (500 mg twice daily) was started (11017). The mechanism is not known, and there is no further data to confirm this interaction.
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Vitamin C can modestly reduce indinavir levels.
Details
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 (11300,93578).
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Vitamin C can increase levothyroxine absorption.
Details
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 (102978).
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Vitamin C might decrease the beneficial effects of niacin on high-density lipoprotein (HDL) cholesterol levels.
Details
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 (7388,11537). 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.
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Acidification of the urine by vitamin C might increase salsalate levels.
Details
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 (3046). However, short-term use of up to 6 grams/day vitamin C does not seem to affect urinary pH or salicylate excretion (10588,10589), suggesting this interaction probably is not clinically significant.
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High-dose vitamin C might reduce the levels and effectiveness of warfarin.
Details
Vitamin C in high doses may cause diarrhea and possibly reduce warfarin absorption (11566). There are reports of two people who took up to 16 grams daily of vitamin C and had a reduction in prothrombin time (9804,9806). Lower doses of 5-10 grams daily can also reduce warfarin absorption. In many cases, this does not seem to be clinically significant (9805,9806,11566,11567). 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) (90942). 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.
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Below is general information about the adverse effects of the known ingredients contained in the product Vitamin C with Bioflavonoids. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
General
...Orally, lemon is well tolerated in amounts commonly found in foods.
A thorough evaluation of safety outcomes has not been conducted on the use of larger amounts.
Most Common Adverse Effects:
Orally: Epigastralgia and heartburn with the regular consumption of fresh lemon juice.
Dermatologic ...Topically, the application of lemon oil might cause photosensitivity, due to furocoumarin derivative content. This occurs most often in fair-skinned people (11019).
Gastrointestinal ...Orally, fresh lemon juice, taken as 60 mL twice daily, has been reported to cause gastrointestinal disturbances in 37% of patients in one clinical trial, compared with 8% of patients in the placebo group. Specifically, of the patients consuming lemon juice, 21% experienced heartburn and 8% experienced epigastralgia, compared to 1% and 3%, respectively, in the placebo group (107489).
General
...Orally, lime juice may cause diarrhea or tooth sensitivity and wear, but these adverse effects are rare (59927,100123,100131).
Topically, lime oil and lime juice can cause allergic contact dermatitis (12,4058,100122,100132). Phytophotodermatitis is common when topical exposure to lime is followed by exposure to the sun (40894,59925,59928,100125,100126,100129).
Intravaginally, 20% to 100% lime juice can cause burning, dryness, pain, itching, erythema, edema, or abnormal bleeding (100127).
Dental ...Orally, tooth sensitivity and erosion of teeth have been reported for a woman who had consumed 150-300 mL of lime juice each night before bed for 3 years without brushing her teeth (100123). Tooth sensitivity has also been reported in a clinical trial (100131).
Dermatologic ...Topically, lime can cause phytophotodermatitis hours to days after exposure (40894,59925,59928,100125,100126,100129). Lime phytophotodermatites related to shaking of Mexican beer and the preparation of mojitos or sangria have been reported. Symptoms include redness, swelling, bullae, and later hyperpigmentation (100125,100126,100129).
Gastrointestinal ...Orally, diarrhea has been reported as an adverse effects in a clinical trial (59927).
Genitourinary ...Intravaginally, 20% lime juice has resulted in burning, dryness, erythema, and edema (100127). Higher doses of 25%, 50%, or 100% lime juice were dose-dependently related to vaginal, cervical, or vulval symptoms, especially pain, itching, and abnormal bleeding. The abnormal bleeding was most common in women that had applied 100% lime juice with a tampon. Peeling, erythema, discharge, and tenderness also occurred (100128).
Immunologic ...Topically, lime can rarely contribute to allergic contact dermatitis (4058,100122,100132).
General ...Orally, sweet orange juice or fruit seem to be well tolerated. Large amounts of sweet orange peel may be unsafe, especially for children. When inhaled, sweet orange essential oil seems to be generally well tolerated.
Gastrointestinal ...There have been reports of intestinal colic in children following ingestion of large amounts of sweet orange peel (11).
Neurologic/CNS ...There have been reports of convulsions in children following ingestion of large amounts of sweet orange peel (11).
General
...Orally, very few adverse effects have been reported with the medicinal use of tangerine.
However, a thorough evaluation of safety outcomes has not been conducted.
Topically, contact dermatitis has been associated with tangerine essential oil (28610).
Dermatologic ...According to one case report, the essential oil of tangerine in a fragrance has been associated with contact dermatitis (28610).
Gastrointestinal ...In a case report, a 5 year-old patient had a phytobezoar that included tangerine residues (28611). In another case report, orange and tangerine caused obstruction of the small intestine (28612).
General
...Orally, intravenously, and topically, vitamin C is well-tolerated.
Most Common Adverse Effects:
Orally: Abdominal cramps, esophagitis, heartburn, headache, osmotic diarrhea, nausea, vomiting. Kidney stones have been reported in those prone to kidney stones. Adverse effects are more likely to occur at doses above the tolerable upper intake level of 2 grams daily.
Topically: Irritation and tingling.
Serious Adverse Effects (Rare):
Orally: There have been rare case reports of carotid inner wall thickening after large doses of vitamin C.
Intravenously: There have been case reports of hyperoxalosis and oxalate nephropathy following high-dose infusions of vitamin C.
Cardiovascular
...Evidence from population research has found that high doses of supplemental vitamin C might not be safe for some people.
In postmenopausal adults with diabetes, supplemental vitamin C intake in doses greater than 300 mg per day is associated with increased risk of cardiovascular mortality. However, dietary intake of vitamin C is not associated with this risk. Also, vitamin C intake is not associated with an increased risk of cardiovascular mortality in patients without diabetes (12498).
Oral supplementation with vitamin C has also been associated with an increased rate of carotid inner wall thickening in men. There is preliminary evidence that supplemental intake of vitamin C 500 mg daily for 18 months can cause a 2.5-fold increased rate of carotid inner wall thickening in non-smoking men and a 5-fold increased rate in men who smoked. The men in this study were 40-60 years old (1355). This effect was not associated with vitamin C from dietary sources (1355).
There is also some concern that vitamin C may increase the risk of hypertension in some patients. A meta-analysis of clinical research suggests that, in pregnant patients at risk of pre-eclampsia, oral intake of vitamin C along with vitamin E increases the risk of gestational hypertension (83450). Other clinical research shows that oral intake of vitamin C along with grape seed polyphenols can increase both systolic and diastolic blood pressure in hypertensive patients (13162).
Dental ...Orally, vitamin C, particularly chewable tablets, has been associated with dental erosion (83484).
Dermatologic ...Topically, vitamin C might cause tingling or irritation at the site of application (6166). A liquid containing vitamin C 20%, red raspberry leaf cell culture extract 0.0005%, and vitamin E 1% (Antioxidant and Collagen Booster Serum, Max Biocare Pty Ltd.) has been reported to cause mild tingling and skin tightness (102355). It is unclear if these effects are due to vitamin C, the other ingredients, or the combination.
Gastrointestinal ...Orally, the adverse effects of vitamin C are dose-related and include nausea, vomiting, esophagitis, heartburn, abdominal cramps, gastrointestinal obstruction, and diarrhea. Doses greater than the tolerable upper intake level (UL) of 2000 mg per day can increase the risk of adverse effects such as osmotic diarrhea and severe gastrointestinal upset (3042,4844,96707,104450). Mineral forms of vitamin C, such as calcium ascorbate (Ester-C), seem to cause fewer gastrointestinal adverse effects than regular vitamin C (83358). In a case report, high dose intravenous vitamin C was associated with increased thirst (96709).
Genitourinary ...Orally, vitamin C may cause precipitation of urate, oxalate, or cysteine stones or drugs in the urinary tract (10356). Hyperoxaluria, hyperuricosuria, hematuria, and crystalluria have occurred in people taking 1 gram or more per day (3042,90943). Supplemental vitamin C over 250 mg daily has been associated with higher risk for kidney stones in males. There was no clear association found in females, but the analysis might not have been adequately powered to evaluate this outcome (104029). In people with a history of oxalate kidney stones, supplemental vitamin C 1 gram per day appears to increase kidney stone risk by 40% (12653). A case of hematuria, high urine oxalate excretion, and the presence of a ureteral stone has been reported for a 9-year-old male who had taken about 3 grams of vitamin C daily since 3 years of age. The condition resolved with cessation of vitamin C intake (90936).
Hematologic ...Prolonged use of large amounts of vitamin C can result in increased metabolism of vitamin C; subsequent reduction in vitamin C intake may precipitate the development of scurvy (15). In one case, a patient with septic shock and a large intraperitoneal hematoma developed moderate hemolysis and increased methemoglobin 12 hours after a high-dose vitamin C infusion. The patient received a blood transfusion and the hemolysis resolved spontaneously over 48 hours (112479).
Neurologic/CNS ...Orally, the adverse effects of vitamin C are dose-related and include fatigue, headache, insomnia, and sleepiness (3042,4844,83475,83476).
Renal ...Hyperoxalosis and oxalate nephropathy have been reported following high-dose infusions of vitamin C. Hyperoxalosis and acute kidney failure contributed to the death of a 76-year-old patient with metastatic adenocarcinoma of the lung who received 10 courses of intravenous infusions containing vitamins, including vitamin C and other supplements over a period of 1 month. Dosages of vitamin C were not specified but were presumed to be high-dose (106618). In another case, a 34-year-old patient with a history of kidney transplant and cerebral palsy was found unresponsive during outpatient treatment for a respiratory tract infection. The patient was intubated for acute hypoxemic respiratory failure, initiated on vasopressors, hydrocortisone, and antibacterial therapy, and received 16 doses of vitamin C 1.5 grams. Serum creatinine level peaked at greater than 3 times baseline and the patient required hemodialysis for oliguria and uncontrolled acidosis. Kidney biopsy revealed oxalate nephropathy with concomitant drug-induced interstitial nephritis (106625). In another case, a 41-year-old patient with a history of kidney transplant presented with fever, nausea, and decreased urine output 4 days after receiving intravenous vitamin C 7 grams for urothelial carcinoma. Serum creatinine levels increased from 1.7 mg/dL to 7.3 mg/dL over those 4 days, and hemodialysis was initiated 3 days after admission due to anuria. Renal biopsy confirmed the diagnosis of acute oxalate nephropathy (109962).
Other ...Intravenously, hypernatremia and falsely elevated ketone levels is reported in a patient with septic shock and chronic kidney disease after a high-dose vitamin C infusion. The hypernatremia resolved over 24 hours after cessation of the infusion (112479).
