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Foundational

Vitamin C · Ascorbic Acid

Correcting deficiency is important; megadoses rarely add benefit.

A
Evidence grade
Replicated human RCTs with hard endpoints

Short answer

500 to 1000 mg/day covers deficiency without side effects. Take with iron-rich meals to boost iron absorption.

Product and dose overview

Vitamin C (Ascorbic Acid) is a foundational with evidence grade A, meaning it is well-supported by replicated human trials. We track 15 products containing Vitamin C. Typical doses range from 48 to 470 mg per serving. The top-ranked product scores 7.7 out of 10 on our composite scale (dose, evidence, price, testing, transparency). Prices range up to $72.00 per month.

Evidence grade: A Products in database: 15 Category: Foundational

Top Vitamin C products

ProductBrandDosePrice/mo3rd-party testedScore
Two-Per-Day Multivitamin (capsules/tablets)Life Extension470 mg$24.50Yes7.7
Vital Proteins Beauty Collagen (with Hyaluronic Acid & Biotin)Vital Proteins180 mg$37.00Yes7.0
Advanced NutrientsThorne HealthTech425 mg$72.00Yes6.8
Seed DM-02 Daily MultivitaminSeed Health90 mg$39.99Yes6.7
Tru Niagen ImmuneTru Niagen (ChromaDex)180 mg$41.00No6.6

Scores are editorial judgments, not a scientific standard. See 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

Trial dose
500 mg
/ day
Range in trials
200 to 1000 mg
/ day
Common forms
Ascorbic acid, Buffered (calcium/sodium ascorbate), Liposomal

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.

Regulatory status

EUFood supplement
USDietary supplement
UKFood supplement
CANHP

Timeline

Regulatory events, evidence grade changes, and key research milestones for Vitamin C, most recent first. Studies link to the paper; regulatory entries name and link the responsible authority.

  • 2025-04 Regulatory single source
    EU Court sharpens the bar for botanical health claims
    A 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.
  • 2024-06 Regulatory confirmed
    EU report identifies 117 supplement substances as potential health risks
    The 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.
    Source →
  • 2023 Research milestone
    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.
    Source →
  • 2022 Research milestone
    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.
    Source →
  • 2020 Research milestone
    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.
    Source →
  • 2006-12 Regulatory confirmed
    EU Health Claims Regulation adopted
    Regulation (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.
    Source →
  • 1997 Regulatory confirmed
    EU introduces the Novel Food Regulation
    Regulation (EC) No 258/97 required any food or food ingredient without a history of consumption in the EU before 15 May 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.
    Source →
  • Research milestone
    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.
    Source →

Landmark studies

Found in these products (15)

All products in our catalog that contain Vitamin C, ranked by our overall score. Ranking is editorial, never paid.

Multi/greens
Ingredients listed
5 ingredients listedlargest listed: Vitamin C 470 mg
Price per serving
$0.41$24.50 · 60 servings
Testing
3rd-party listed · no public lab certificate

Multi-ingredient bundle

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 7.7/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

100%
of trial dose
$0.43
per research-dose day, not label serving
0Trial dose2×
Catalog price · Confirm current price with www.lifeextension.com
Connective tissue
Ingredients listed
3 ingredients listedlargest listed: Collagen Peptides 15 g
Price per serving
$2.47$37.00 · 15 servings
Testing
3rd-party listed · no public lab certificate

Multi-ingredient bundle

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 7.0/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

100%
of trial dose
$1.64
per research-dose day, not label serving
0Trial dose2×
Catalog price · Confirm current price with www.vitalproteins.com
Thorne HealthTech
Advanced Nutrients
Multi/greens
Ingredients listed
10 ingredients listedlargest listed: Vitamin C 425 mg
Price per serving
$2.40$72.00 · 30 servings
Testing
3rd-party listed · no public lab certificate

Multi-ingredient bundle

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 6.8/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

100%
of trial dose
$2.82
per research-dose day, not label serving
0Trial dose2×
Catalog price · Confirm current price with www.thorne.com
Multi/greens
Ingredients listed
6 ingredients listedlargest listed: Vitamin C 90 mg
Price per serving
$1.33$39.99 · 30 servings
Testing
3rd-party listed · no public lab certificate

Multi-ingredient bundle

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 6.7/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

100%
of trial dose
$1.33
per research-dose day, not label serving
0Trial dose2×
Catalog price · Confirm current price with seed.com
Tru Niagen (ChromaDex)
Tru Niagen Immune
Vitamin
Ingredients listed
4 ingredients listedlargest listed: Vitamin C 180 mg
Price per serving
$1.37$41.00 · 30 servings
Testing
None listed

Elemental vs compound: check label

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 6.6/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

100%
of trial dose
$2.73
per research-dose day, not label serving
0Trial dose2×
Catalog price · Confirm current price with www.truniagen.com
Connective tissue
Ingredients listed
6 ingredients listedlargest listed: Collagen Peptides 10 g
Price per serving
$1.97$59.00 · 30 servings
Testing
3rd-party listed · no public lab certificate

Elemental vs compound: check label

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 6.6/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

100%
of trial dose
$1.97
per research-dose day, not label serving
0Trial dose2×
Catalog price · Confirm current price with www.vitalproteins.com
Elysium Health
Cofactor
Connective tissue
Ingredients listed
4 ingredients listedlargest listed: Collagen Peptides 20 g
Price per serving
$2.68$75.00 · 28 servings
Testing
None listed

Multi-ingredient bundle

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 6.5/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

800%
of trial dose
$1.34
per research-dose day, not label serving
800% · over 2× trial dose0Trial dose2×
Catalog price · Confirm current price with www.elysiumhealth.com
Avea Life
Collagen Activator
Connective tissue
Ingredients listed
4 ingredients listedlargest listed: Glycine 5 g
Price per serving
$3.07$92.00 · 30 servings
Testing
None listed

Multi-ingredient bundle

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 6.5/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

100%
of trial dose
$1.84
per research-dose day, not label serving
0Trial dose2×
Catalog price · Confirm current price with avea-life.com
NOVOS Labs
NOVOS Core
Longevity stack
Ingredients listed
12 ingredients listedlargest listed: Glycine 1,000 mg
Price per serving
$2.97$89.00 · 30 servings
Testing
3rd-party listed · no public lab certificate

Multi-ingredient bundle

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 6.3/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

50%
of trial dose
$14.83
per research-dose day, not label serving
0Trial dose2×
Catalog price · Confirm current price with novoslabs.com
Momentous
Longevity
NAD+ booster
Ingredients listed
8 ingredients listedlargest listed: NAC 600 mg
Price per serving
$3.67$109.95 · 30 servings
Testing
3rd-party listed · no public lab certificate

Multi-ingredient bundle

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 6.2/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

100%
of trial dose
$2.20
per research-dose day, not label serving
0Trial dose2×
Catalog price · Confirm current price with www.livemomentous.com
AG1 (Athletic Greens)
AG1 Foundational Nutrition
Longevity stack
Ingredients listed
4 ingredients listedlargest listed: Greens blend 4,000 mg
Price per serving
$3.30$99.00 · 30 servings
Testing
3rd-party listed · no public lab certificate

CFU not stored

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 6.0/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

Catalog price · Confirm current price with drinkag1.com
Vitamin
Ingredients listed
7 ingredients listedlargest listed: Vitamin C 180 mg
Price per serving
$1.00$30.00 · 30 servings
Testing
None listed

Elemental vs compound: check label

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 6.0/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

90%
of trial dose
$2.78
per research-dose day, not label serving
0Trial dose2×
Catalog price · Confirm current price with www.vitalproteins.com
Elysium Health
Format
Antioxidant
Ingredients listed
3 ingredients listedlargest listed: Vitamin C 90 mg
Price per serving
$2.00$60.00 · 30 servings
Testing
3rd-party listed · no public lab certificate

Elemental vs compound: check label

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 5.9/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

45%
of trial dose
$11.11
per research-dose day, not label serving
0Trial dose2×
Catalog price · Confirm current price with www.elysiumhealth.com
Life Extension
Super K
Vitamin
Vitamin per serving
Vitamin C 10 mgSoftgel · 90 servings
Price per serving
$0.33$30.00 · 90 servings
Testing
3rd-party listed · no public lab certificate

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 5.8/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

5%
of trial dose
$16.67
per research-dose day, not label serving
0Trial dose2×
Catalog price · Confirm current price with www.lifeextension.com
Sirtuin activator
Ingredients listed
4 ingredients listedlargest listed: Resveratrol 200 mg
Price per serving
$0.47$28.21 · 60 servings
Testing
None listed

Multi-ingredient bundle

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 5.6/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

100%
of trial dose
$1.18
per research-dose day, not label serving
0Trial dose2×
Catalog price · Confirm current price with acuatlanta.net
Editorial guides

Buying guides and comparisons

Neighbouring molecules

Related ingredients

See all in Foundational →

Molecules in the same class, plus the actives most often formulated alongside Vitamin C in our catalogue.

Omega-3 (EPA/DHA)Asame categoryVitamin D3Asame categoryVitamin K2Bsame categoryMagnesiumAsame categoryVitamin B12Asame categoryFolate (5-MTHF)Bsame categoryZincAsame categorySeleniumAsame category
Product shelves
See all in Connective tissue (4)See all in Multi/greens (3)See all in Vitamin (3)See all in Longevity stack (2)See all in NAD+ booster (1)See all in Antioxidant (1)See all in Sirtuin activator (1)

See Vitamin C in context: the mechanism it acts through, the biomarker it moves, the products that dose it, and the trials that tested it.

View Vitamin C on the Longevity Map →

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 day, with a range of 200 to 1000 mg per day. 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 15 products containing Vitamin C. The top-ranked product scores 7.7 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.

Independently checked

Data verification

Evidence grade
A
Replicated human RCTs with hard endpoints
Research dose
500 mg
Products tracked
15
Updated continuously
Safety signal
High doses cause GI upset. Buffered forms gentler. Liposo...

Evidence grades are reviewed when new human RCTs are published. Product counts update automatically as new products are added. Dose ranges reflect published trial data, not brand recommendations. Read how we verify.