Vitamin C · Ascorbic Acid
Correcting deficiency is important; megadoses rarely add benefit.
Short answer
Vitamin C (Ascorbic Acid) is a foundational with evidence grade A, meaning it is well-supported by replicated human trials. We track 12 produkter containing Vitamin C. Typical doses range from 90.0 to 470.0 mg per portion. The top-ranked product scores 7.1 out of 10 on our composite scale (dose, evidence, price, testing, transparency). Prices range up to $72.00 per månad.
Top Vitamin C produkter
| Product | Varumärke | Dose | Pris/mo | 3rd-party tested | Poäng |
|---|---|---|---|---|---|
| Two-Per-Day Multivitamin (capsules/tablets) | 470.0 mg | $24.50 | Yes | 7.1 | |
| Vital Proteins Beauty Collagen (with Hyaluronic Acid & Biotin) | 180.0 mg | $37.00 | Yes | 6.6 | |
| Vital Proteins Bioactive Collagen Complex Bone & Joint Support | 125.0 mg | $59.00 | Yes | 6.5 | |
| Seed DM-02 Daily Multivitamin | 90.0 mg | $39.99 | Yes | 6.5 | |
| Advanced Nutrients | 425 mg | $72.00 | Yes | 6.3 |
Scores are editorial judgments, not a scientific standard. Se how we score.
What it is
Essential vitamin for collagen synthesis, immune function, and iron absorption. Deficiency (scurvy) still occurs in restricted diets.
Why people take it
Correcting deficiency reduces respiratory infections and supports collagen. Megadose claims (>1 g/day) generally overhyped.
Our verdict
500 to 1000 mg/day covers deficiency without side effects. Take with iron-rich meals to boost iron absorption.
Structure & class
L-ascorbic acid. Water-soluble, urine-excreted at saturation.
Mechanism & clinical data
Bioavailability plateaus above ~200 mg per dose; higher doses need split administration.
Pharmacokinetics
~30 minutes (plasma).
Dose & forms
What to watch out for
High doses cause GI upset. Buffered forms gentler. Liposomal marketing typically overstated for chronic use.
Where this dose comes from
The trial dose above is our editorial pick from the published human trials for this ingredient. We choose the dose that the best-available studies used on the endpoint most relevant to longevity. The range shows the lowest and highest doses tested in published trials. The landmark studies below are the papers we read to set it. You can click through and check our work.
When new trials publish, our automated sweeps flag them. If a new study materially changes the dose, we update it through editorial review and record the old dose, new dose, and the triggering study in every affected product's recommendation history. The dose is never changed automatically.
Regelverk status
Timeline
Regelverk events, evidence grade changes, and key research milestones for Vitamin C, most recent first. Every entry links to its primär source.
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EU Court sharpens the bar for botanical health claimsA Court of Justice of the European Union ruling in april 2025 further tightened the requirements for how botanical ingredients (herbs, plant extracts) can be marketed with health claims in the EU, effectively removing much of the flexibility of the on-hold list.
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EU report identifies 117 supplement substances as potential health risksThe HoA Working Group on Food Supplements (26 European countries) published its first report evaluating 117 substances used in food supplements. Of these, 65 were assessed as likely novel foods, 6 were already regulated, 34 had insufficient data, and 12 were prioritized for Article 8 restriction under Regulation (EC) No 1925/2006. The 12 priority substances include ashwagandha, curcumin, melatonin, piperine, St. John's wort, coumarin, p-synephrine, maca, holy basil, Melaleuca, black cohosh, and L-tryptophan. The report drew on 1,500 RASFF alerts reviewed between 2017 and mid-2022.
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Vitamin C + telomere length 2023 (NHANES)In 7,094 NHANES participants, higher dietary vitamin C intake was significantly associated with longer telomere length after adjusting for age, sex, race, and BMI.
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Vitamin C umbrella review 2022 (76 meta-analyses)An umbrella review of 76 meta-analyses found that higher vitamin C intake (50-100 mg/day increment) was associated with reduced all-cause mortality and cardiovascular disease risk.
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Vitamin C and CVD 2020 (Antioxidants)This review of clinical and preclinical studies summarizes evidence that vitamin C's antioxidant and endothelial-protective properties may benefit coronary heart disease, heart failure, and hypertension, while noting inconsistent trial results.
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EU Health Claims Regulation adoptedRegulation (EC) No 1924/2006 laid down harmonised rules for nutrition and health claims made on foods, including supplements. Only claims listed in the EU Register of authorised claims can be used. Rejected botanical claims are held in a separate on-hold list.
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EU introduces the Novel Food RegulationRegulation (EC) No 258/97 required any food or food ingredient without a history of consumption in the EU before 15 maj 1997 to be authorised before being placed on the market. This is the framework that captures NMN, spermidine as a supplement ingredient, urolithin A, and many other longevity actives.
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Cochrane: Vitamin C for common coldThis Cochrane review of RCTs found regular vitamin C supplementation modestly reduces common cold duration and severity, though it does not reduce incidence in the general population.
Landmark studies
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Vitamin C umbrella review 2022 (76 meta-analyses)
An umbrella review of 76 meta-analyses found that higher vitamin C intake (50-100 mg/day increment) was associated with reduced all-cause mortality and cardiovascular disease risk.
Läs studie → -
Vitamin C + telomere length 2023 (NHANES)
In 7,094 NHANES participants, higher dietary vitamin C intake was significantly associated with longer telomere length after adjusting for age, sex, race, and BMI.
Läs studie → -
Vitamin C and CVD 2020 (Antioxidants)
This review of clinical and preclinical studies summarizes evidence that vitamin C's antioxidant and endothelial-protective properties may benefit coronary heart disease, heart failure, and hypertension, while noting inconsistent trial results.
Läs studie → -
Cochrane: Vitamin C for common cold
This Cochrane review of RCTs found regular vitamin C supplementation modestly reduces common cold duration and severity, though it does not reduce incidence in the general population.
Läs studie →
Found in these produkter (12)
Alla produkter in our catalog that contain Vitamin C, ranked by our overall score. Ranking is editorial, never paid.
Buying guides and comparisons
Related ingredients
Se alla in Foundational →Molekyler in the same class, plus the actives most often formulated alongside Vitamin C in our catalogue.
Frequently asked questions
What is Vitamin C?
Essential vitamin for collagen synthesis, immune function, and iron absorption. Deficiency (scurvy) still occurs in restricted diets.
What dose of Vitamin C should I take?
The trial dose in published human studies is 500 mg per dag, with a range of 200 to 1000 mg per dag. Always consult a qualified clinician before starting any supplement.
Is Vitamin C safe?
High doses cause GI upset. Buffered forms gentler. Liposomal marketing typically overstated for chronic use.
What is the best Vitamin C supplement?
We track 12 produkter containing Vitamin C. The top-ranked product scores 7.1 out of 10 on our composite scale, which evaluates dose, evidence, price, third-party testing, and transparency. See the comparison table above. Scores are editorial judgments, not a scientific standard.
What is the evidence grade for Vitamin C?
Vitamin C has evidence grade A, meaning it is well-supported by replicated human trials. Grade A means replicated human RCTs with hard endpoints. Grade B means human RCTs with biomarker outcomes. Grade C means mixed or small human trials. See our evidence grading methodology.
Data verification
Bevisning grades are reviewed when new human RCTs are published. Product counts update automatically as new produkter are added. Dose ranges reflect published trial data, not brand recommendations. Read how we verify.