Two capsules contain: Vitamin C (ascorbic acid) 1200 mg • Biotin 3000 mcg • Horsetail aerial part extract (standardized to contain 7.8% silica) 50 mg • L-Cysteine 500 mg • Nettle leaf 50 mg • Horsetail aerial part 103 mg. Other Ingredients: Gelatin, Arrowroot, Purified Water, MCT, Vitamin E, Rosemary Oil.
Brand name products often contain multiple ingredients. To read detailed information about each ingredient, click on the link for the individual ingredient shown above.
Below is general information about the effectiveness of the known ingredients contained in the product Hair Formula. 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 Hair Formula. 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 orally and appropriately. Biotin has been safely used in doses up to 300 mg daily for up to 6 months. A tolerable upper intake level (UL) has not been established (1900,6243,95662,102965). ...when applied topically as cosmetic products at concentrations of 0.0001% to 0.6% biotin (19344).
POSSIBLY SAFE ...when used intramuscularly and appropriately (8468,111366).
CHILDREN: LIKELY SAFE
when used orally and appropriately.
Biotin has been safely used at adequate intake doses of 5-25 mcg daily for up to 6 months (173,6243,19347,19348,111365). A tolerable upper intake level (UL) has not been established.
PREGNANCY AND LACTATION: LIKELY SAFE
when used orally and appropriately.
Biotin has been safely used at the adequate intake (AI) dose of 30 mcg daily during pregnancy and 35 mcg daily during lactation. It has also been used in supplemental doses of up to 300 mcg daily (6243,7878). A tolerable upper intake level (UL) has not been established.
POSSIBLY UNSAFE ...when horsetail products containing thiaminase are used orally, long-term. Thiaminase is an enzyme that destroys thiamine, which could theoretically lead to thiamine deficiency. In Canada, horsetail products are required to be thiaminase-free (105301).
PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.
LIKELY SAFE ...when used orally in amounts found in foods. There is insufficient reliable information available about the safety of L-cysteine when used orally in amounts greater than those found in foods or when used topically.
PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in amounts found in foods.
There is insufficient reliable information available about the safety of amounts greater than those found in foods; avoid use. Some research suggests that taking L-cysteine during lactation increases levels of free L-cysteine in breastmilk. However, these levels are lower than those found in some commercial hydrolyzed protein infant formulas (109718).
POSSIBLY SAFE ...when used orally and appropriately. Stinging nettle root 360-600 mg has been used safely for up to 1 year (5093,11230,15195,76406,96744). ...when used topically and appropriately (12490).
PREGNANCY: LIKELY UNSAFE
when used orally due to possible abortifacient and uterine-stimulant effects (4,6,19).
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 Hair Formula. 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 horsetail with antidiabetes drugs might increase the risk of hypoglycemia.
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Theoretically, taking horsetail with diuretic drugs might increase potassium loss and the risk of hypokalemia.
Details
Laboratory research shows that various species of horsetail have diuretic properties (13574,13575). Due to its diuretic effects, there has been concern that taking horsetail along with potassium-depleting diuretics might increase the risk for hypokalemia. However, pharmacokinetic research in humans shows that taking horsetail 900 mg daily for 4 days does not affect urinary excretion of electrolytes, including potassium and sodium, despite having a diuretic effect similar to taking hydrochlorothiazide 25 mg daily (92288). It is unclear if taking horsetail for a longer duration would affect electrolyte levels. Until more is known, use with caution.
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Theoretically, horsetail might decrease the levels and clinical effects of efavirenz.
Details
In two case reports, patients were found to have detectable viral loads when taking horsetail-containing supplements along with an antiretroviral regimen that included efavirenz. In one case, the antiretroviral regimen included zidovudine, lamivudine, and efavirenz; in the other case, the regimen consisted of emtricitabine, tenofovir disoproxil fumarate, and efavirenz. One month after discontinuing horsetail, the viral loads became undetectable in both cases. The exact mechanism of this interaction is unknown (97573). It is also unclear if this interaction is specific to efavirenz or if it is related to various components of antiretroviral therapy.
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Theoretically, horsetail might increase the levels and adverse effects of lithium.
Details
Animal research suggests that horsetail has diuretic properties (13574). Theoretically, due to these potential diuretic effects, horsetail might reduce excretion and increase levels of lithium. The dose of lithium might need to be decreased.
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Theoretically, horsetail might decrease the levels and clinical effects of NRTIs.
Details
In two case reports, patients were found to have detectable viral loads when taking horsetail-containing supplements along with an antiretroviral therapy. In one case, the antiretroviral regimen included zidovudine, lamivudine, and efavirenz; in the other case, the regimen consisted of emtricitabine, tenofovir disoproxil fumarate, and efavirenz. One month after discontinuing the supplement, the viral loads became undetectable in both cases. The exact mechanism of these interactions is unknown (97573). It is also unclear if these interactions are specific to NRTIs or if they are related to various components of antiretroviral therapy.
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Theoretically, taking L-cysteine supplements with antidiabetes drugs might increase the risk of hypoglycemia.
Details
Animal research suggests that L-cysteine can have hypoglycemic effects (109722).
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Theoretically, stinging nettle might have additive effects with antidiabetes drugs.
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Theoretically, combining stinging nettle with diuretic drugs may have additive effects.
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Theoretically, stinging nettle might reduce excretion and increase levels of lithium.
Details
Animal research suggests that stinging nettle has diuretic and natriuretic properties, which could alter the excretion of lithium (76402). The dose of lithium might need to be decreased.
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There is some concern that stinging nettle might decrease the effects of anticoagulant drugs such as warfarin.
Details
Stinging nettle contains a significant amount of vitamin K (19). When taken in large quantities, this might interfere with the activity of warfarin.
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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 Hair Formula. 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 and topically, biotin is generally well tolerated.
Most Common Adverse Effects: None.
Gastrointestinal ...Orally, high-dose biotin has been rarely associated with mild diarrhea. Transient mild diarrhea was reported by 2 patients taking biotin 300 mg daily (95662).
Pulmonary/Respiratory ...In one case report in France, a 76-year-old female frequent traveler developed eosinophilic pleuropericarditis after taking biotin 10 mg and pantothenic acid 300 mg daily for 2 months. She had also been taking trimetazidine for 6 years (3914). Whether eosinophilia in this case was related to biotin, pantothenic acid, other substances, or patient-specific conditions is unknown. There have been no other similar reports.
General
...There is limited clinical research evaluating the safety of horsetail.
Most Common Adverse Effects:
Orally: Abdominal distension, increased bowel movements, and nausea.
Dermatologic ...In one case report, a patient developed seborrheic dermatitis after topical application of horsetail, requiring treatment with local epinephrine and oral antihistamines. The nicotine component of horsetail was determined to be the likely cause of this reaction (13563).
Gastrointestinal ...Orally, horsetail has been associated with mild gastrointestinal side effects including abdominal distension, increased frequency of bowel movements, and nausea (55576). Orally, chronic consumption of horsetail infusion has been associated with acute pancreatitis. In a case report, a 56-year-old female presenting with recurrent mild acute pancreatitis every 6-7 months, previously thought to be drug-induced, discontinued ingesting horsetail infusions. The patient had a history of bilateral adrenal gland removal and was being treated for hypertension, dyslipidemia, and hormone replacement, and then self-medicated with horsetail infusions. After discontinuing horsetail infusions, there were no further recurrences of pancreatitis during a 14-month follow-up (97574).
Hepatic ...In one case report, a patient with asymptomatic hepatitis B developed symptomatic liver failure following consumption of boiled horsetail juice 500 mL daily for 2 weeks. Liver enzymes returned to normal following discontinuation of the juice (92291). It is not known if the horsetail juice was contaminated or mixed with other ingredients.
Immunologic ...Horsetail has been associated with cross-allergenicity with carrots (13577).
Renal ...There are at least 4 case reports of hyponatremia thought to be at least partially associated with horsetail consumption. In one case report, an elderly patient who had taken oral horsetail 15 mg daily for 10 years presented with hyponatremia and syndrome of inappropriate secretion of antidiuretic hormone (SIADH) secondary to reduced oral intake and nausea for the previous 2 days. Horsetail was thought to be a contributing factor. The patient's symptoms resolved after 5 days of treatment with oral sodium chloride and fluid restriction (108851).
Other ...Crude horsetail contains thiaminase, which can cause thiamine deficiency with prolonged consumption. Canadian Equisetum arvense products are required to be certified as free from thiaminase-like activity (55579,105301). In one case report, the development of autism in a child exposed to both horsetail and alcohol during pregnancy was thought to be caused by thiamine deficiency attributed to this combination (92292). However, it is not known if other genetic or environmental factors were involved in the development of this condition in utero.
General ...Orally, L-cysteine is well tolerated in amounts found in foods. When used in higher doses or when applied topically, no adverse effects have been reported. However, a thorough evaluation of safety outcomes has not been conducted.
General
...Orally, stinging nettle seems to be generally well tolerated.
Most Common Adverse Effects:
Orally: Constipation, diarrhea.
Topically: Contact with the raw plant causes itching, rash, and stinging.
Dermatologic ...Topically, fresh stinging nettle leaves and stalk can cause localized rash, itching, and stinging (12490,76399,76412,76414,76417,76428,76448,96746). Usually, short exposure to stinging nettle results in a transient urticarial reaction and a stinging sensation which may persist for more than 12 hours (76399,76414,76417,96746). In one report, a patient placed a fresh stinging nettle leaf on the tongue to suck out the sap of the leaf. Severe tongue edema, pain, and urticaria developed within 5 minutes. Symptoms continued for several hours after the leaf was removed (15197). In another case report, a young couple intoxicated with methamphetamine fell and laid in a stinging nettle bush for 20 minutes, after which urticaria and pain continued for 2-3 weeks, and a heightened sensitivity to cold persisted for several months (96746).
Endocrine
...A case of gynecomastia has been reported for a 33-year-old male who consumed stinging nettle tea 2 cups daily for one month prior to symptom onset.
The condition subsided one month after discontinuing stinging nettle tea (76410).
There have been two cases of galactorrhea associated with the consumption of stinging nettle for one month (76410,108902). In one case, a 33-year-old female consuming stinging nettle tea showed high levels of estradiol and low levels of follicle stimulating hormone (FSH) and luteinizing hormone (LH). The levels of these hormones normalized 6 weeks after discontinuing stinging nettle tea (76410). In the other case report describing a 30-year-old female self-treating with stinging nettle 500 mg daily, hormone levels were not reported; however, a mammogram showed scattered areas of fibroglandular density and benign-appearing calcifications. This patient had complete resolution of symptoms 1 week after discontinuation of stinging nettle (108902).
Gastrointestinal ...Orally, stinging nettle root can cause gastrointestinal complaints, including diarrhea and constipation (1,7,11230). Stinging nettle above ground parts may cause mild gastrointestinal discomfort when taken on an empty stomach (7035). Stinging nettle juice may cause diarrhea (1). One patient taking a combination product containing stinging nettle root extract and pygeum bark extract (Prostatonin, Pharmaton) experienced continual gastrointestinal pain and hyperperistalsis. It is not clear if this effect was due to stinging nettle or pygeum (70230).
Genitourinary ...There is a case report of decreased ejaculatory volume associated with an herbal blend product containing stinging nettle root extract, saw palmetto extract, pumpkin seed oil extract, lemon bioflavonoid extract, and beta-carotene (5093). It is unclear if this was due to stinging nettle, other ingredients, or the combination.
Hepatic ...A case of idiosyncratic drug-induced liver disease (DILI) is reported in a 36-year-old female who presented with abdominal pain after 1 month of taking an herbal liver detox tea containing stinging nettle and other ingredients. Remarkable laboratory values included elevated liver enzymes, alkaline phosphatase, and total bilirubin. The patient received a loading dose of N-acetylcysteine and was hospitalized for 12 days (112178). However, it is unclear if the adverse effect was due to the stinging nettle, other ingredients, or the combination.
Other ...Orally, stinging nettle root can cause sweating (1,7).
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).
