Vitamin C
Also known as: Ascorbic acid, L-ascorbic acid, Ascorbate, Sodium ascorbate, Calcium ascorbate
Overview
Vitamin C is an essential water-soluble antioxidant required for collagen synthesis, immune function, and iron absorption. Calcium ascorbate is a buffered form that reduces gastric irritation.
Compare Forms
5 formsDifferent chemical forms vary in absorption, side effects, and best use cases. Higher bioavailability scores indicate better absorption.
Liposomal Vitamin C
HIGH 100Ascorbic acid encapsulated in phospholipid liposomes
๐ก Highest bioavailability. Bypasses normal saturable transporters; achieves higher plasma levels than equivalent oral ascorbic acid.
- โข Highest plasma levels
- โข No GI distress at high doses
- โข Cellular uptake
- โข Expensive
- โข Some products poorly formulated
- โข Fishy taste in some brands
๐ Worth it for therapeutic doses (>2 g/day) or sensitive stomachs
Ascorbic Acid
HIGH 90Pure L-ascorbic acid, the standard form
๐ก Excellent up to ~200 mg per dose; saturates above this. Split larger daily doses.
- โข Best researched form
- โข Cheapest
- โข Identical to dietary vitamin C
- โข Acidic, can erode enamel
- โข GI upset at high doses
- โข Saturable absorption
๐ Ideal for most people. Split into 2-3 daily doses for higher intake.
Calcium Ascorbate (Ester-C)
HIGH 85Buffered form bound to calcium
๐ก Comparable to ascorbic acid; gentler on the GI tract.
- โข Non-acidic
- โข Gentle on stomach
- โข Provides small calcium boost
- โข More expensive
- โข Adds calcium (consider if already supplementing)
๐ Good choice for those who get heartburn from regular vitamin C
Sodium Ascorbate
HIGH 85Buffered form bound to sodium
๐ก Comparable to ascorbic acid; pH-neutral.
- โข Non-acidic
- โข Used in IV preparations
- โข Adds sodium (avoid if hypertensive)
- โข Less common
๐ Watch sodium load if on a low-sodium diet
Ascorbyl Palmitate
GOOD 70Fat-soluble form of vitamin C
๐ก Hydrolyzed in gut; lower systemic bioavailability than ascorbic acid.
- โข Crosses cell membranes
- โข Used in cosmetics
- โข Lower oral bioavailability
- โข Often paired with regular C anyway
๐ Niche use case; not a substitute for regular vitamin C
Dosage
Safe long-term
Higher needs when sick
Mechanism of Action
- โข Collagen hydroxylation cofactor
- โข Electron donor antioxidant
- โข Immune cell support
- โข Enhances iron absorption
Evidence Quality
Essential vitamin with extensive research
Safety & Contraindications
- โข Kidney stones risk at very high doses
- โข Hemochromatosis
- โข G6PD deficiency (IV)
- โข GI upset at high doses
- โข Diarrhea
Likely safe at normal doses - consult provider
Caution with kidney stones history
Interactions
- โข May affect some chemo drugs
- โข Enhances iron absorption
- โข Citrus, peppers, berries
Stacking & Synergies
Buying Guide
- โข Form specified
- โข Divide doses for better absorption
- โข Bowel tolerance indicates saturation
- โข More expensive
- โข Taste can be unpleasant
- โข Quality varies greatly
- โข Higher doses needed for cortisol effects
- โข Divide doses
- โข Adrenals need vitamin C
- โข Must have for collagen to work
- โข Take together with collagen
- โข Increase during illness
- โข Liposomal for high doses without GI issues
- โข Individual tolerance varies
- โข Also getting vitamin C benefit
- โข Buffered forms gentler
Frequently Asked About Vitamin C
How much Vitamin C should I take?
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Who should not take Vitamin C?
Top Products with Vitamin C
Highest-scored catalog products containing Vitamin C, ranked by our scoring engine.
MediClear-SGSโข - VanillaThorne95
Vitamin C 1,000 mg (formerly Ascorbic Acid)Thorne95
Thyroid Health Complex (formerly Thyrocsin)Thorne94
Basic Nutrients 2/DayThorne93
Related Guides
In-depth guides covering Vitamin C โ protocols, comparisons, and use cases.
Educational content based on published research and our scoring methodology. Not medical advice โ consult a qualified healthcare provider before starting, stopping, or changing supplements, especially if you take medications, are pregnant, or have a medical condition.