Vitamin C Side Effects
Generic Name: ascorbic acid
Note: This page contains side effects data for the generic drug ascorbic acid. It is possible that some of the dosage forms included below may not apply to the brand name Vitamin C.
It is possible that some side effects of Vitamin C may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.
For the Consumer
Applies to ascorbic acid: oral capsule, oral capsule extended release, oral capsule liquid filled, oral granule, oral liquid, oral lozenge/troche, oral powder, oral powder for solution, oral powder for suspension, oral solution, oral syrup, oral tablet, oral tablet chewable, oral tablet extended release, oral wafer
As well as its needed effects, ascorbic acid (the active ingredient contained in Vitamin C) may cause unwanted side effects that require medical attention.
If any of the following side effects occur while taking ascorbic acid, check with your doctor or nurse as soon as possible:Less common or rare - with high doses
- Side or lower back pain
Some ascorbic acid side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:Less common or rare - with high doses
- dizziness or faintness (with the injection only)
- flushing or redness of skin
- increase in urination (mild)
- nausea or vomiting
- stomach cramps
For Healthcare Professionals
Applies to ascorbic acid: compounding powder, injectable solution, oral capsule, oral gum, oral liquid, oral tablet, oral tablet chewable, oral tablet disintegrating, oral tablet extended release
Renal side effects have included oxalate and urate kidney stones.[Ref]
Hyperoxaluria appears to be dose-related.[Ref]
Migraine headache has been reported with a daily dose of 6 grams.
The manufacturer reports temporary dizziness and faintness may be associated with too rapid of a rate during intravenous administration.[Ref]
Nervous system side effects have included dizziness, faintness, fatigue, and headache in less than 1% of patients. Migraine headache has also been reported.[Ref]
Conditional scurvy is reported to occur following excessive doses of ascorbic acid (the active ingredient contained in Vitamin C) over a prolonged period of time. The mechanism of action for this condition is thought to be that large doses of ascorbic acid condition the patient over time for rapid clearance of ascorbic acid resulting in scurvy. The plasma levels of ascorbic acid appear to remain within normal limits. The actual existence of conditional scurvy remains controversial.[Ref]
Other side effects have included flank pain in less than 1% of patients. Conditional scurvy has also been reported.[Ref]
Gastrointestinal side effects have included nausea, diarrhea, abdominal cramps, and esophagitis.[Ref]
Nausea, diarrhea, and abdominal cramps appears to be associated with doses exceeding 2 g per day, although there have been some reports with as little as 1 g per day.
Esophagitis appears to be associated with prolonged or increased contact of ascorbic acid tablets with the esophageal mucosa.[Ref]
The majority of hemolysis reports have been associated with patients who have concurrent glucose-6-phosphate dehydrogenase deficiency.[Ref]
Hematologic side effects have included hemolysis.[Ref]
Local side effects have included transient mild soreness at the site of injection.[Ref]
1. Levine M, Dhariwal KR, Welch RW, Wang Y, Park JB "Determination of optimal vitamin C requirements in humans." Am J Clin Nutr 62(6 Suppl) (1995): s1347-56
2. Hathcock JN "Vitamins and minerals: Efficacy and safety." Am J Clin Nutr 66 (1997): 427-37
3. "How much vitamin C do you need?" JAMA 281 (1999): 1460
4. "Product Information. Cemill (ascorbic acid)." Abbott Pharmaceutical, Abbott Park, IL.
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