Key Information
Vitamin C is safe and inexpensive. As an antioxidant, it has a plausible mechanism for influencing the course of neurodegenerative diseases. Two flawed preclinical studies by the same group showed benefits in a mouse model of familial ALS. There are two case reports in which it was associated with improvement. However, there are multiple possible explanations for the improvement in these cases. It is not clear which if any dose of vitamin C might be beneficial for PALS; a small clinical trial using oral vitamin C at 2,000 mg daily was unable to demonstrate benefits in PALS. Based on this negative trial, we currently advise against using vitamin C to treat ALS.
Mechanistic plausibility
Mechanistic plausibility
Mechanistic plausibility - C
Mechanistic plausibility
Mechanistic plausibility
Mechanistic plausibility
Pre-clinical models (animal or cell models recognized by ALSUntangled reviewers to be relevant to ALS)
Grade A: Two or more peer-reviewed publications reporting benefits in well-designed studies.
Animal studies are assumed to be ‘well designed’ when they follow published guidelines. When they deviate from these they are considered ‘flawed’.
Pre-clinical models (animal or cell models recognized by ALSUntangled reviewers to be relevant to ALS)
Grade B: One peer-reviewed publication reporting benefits in a well-designed study.
Animal studies are assumed to be ‘well designed’ when they follow published guidelines. When they deviate from these they are considered ‘flawed’.
Pre-clinical models (animal or cell models recognized by ALSUntangled reviewers to be relevant to ALS)
Grade C: One or more peer-reviewed publication(s) reporting benefits in flawed studies.
Animal studies are assumed to be ‘well designed’ when they follow published guidelines. When they deviate from these they are considered ‘flawed’.
Pre-clinical models (animal or cell models recognized by ALSUntangled reviewers to be relevant to ALS)
Pre-clinical models (animal or cell models recognized by ALSUntangled reviewers to be relevant to ALS)
Pre-clinical models (animal or cell models recognized by ALSUntangled reviewers to be relevant to ALS)
Patient case reports
Patient case reports
Patient case reports
Patient case reports
Patient case reports
Patient case reports
Patient trials
Patient trials
Patient trials
Grade D: One or more peer-reviewed publications reporting benefits in a flawed trial.
Flawed trials means those in which there are identifiable problems with patient selection, randomization, blinding, controls or follow-up. These have ‘high or unclear risk of bias’ according to published criteria. Well-designed trials are those that have ‘low risk of bias’.
Patient trials
Patient trials
Risks (harms that occurred on this treatment)
Risks (harms that occurred on this treatment)
Risks (harms that occurred on this treatment)
Grade B (oral): More than 0% but less than10% of exposed patients experienced harms (no hospitalizations or deaths)
Grade D (intravenous): More than 0% but less than 5% of exposed patients experienced death or hospitalizations
Risks (harms that occurred on this treatment)
Risks (harms that occurred on this treatment)
Risks (harms that occurred on this treatment)
Grade D: More than 0% but less than 5% of exposed patients experienced death or hospitalizations
Grade F: At least 5% of exposed patients experienced death or hospitalization