Vitamin C supplements, compared
8 products we’ve reviewed list vitamin c as a key ingredient. Here’s what it does, what the research uses — and how much each product actually contains.
What it is
An antioxidant needed to make collagen and support immune function.
What the research uses
Adults need 90–120 mg a day, depending on sex and life stage. The upper limit for adults is 2,000 mg a day; more can cause digestive upset.
Educational information, not medical advice. Talk to a healthcare professional before starting a supplement, especially if you are pregnant, nursing or take medication.
Every product, dose by dose
| Product | Vitamin C per serving | Form | Score |
|---|---|---|---|
 cGMP facilityKosherHalal | 1,000 mgVitamin C (as ascorbic acid) | Tablet | 8.1 |
 NSF Certified for Sport | 500 mgVitamin C (ascorbic acid) | Powder | 7.3 |
 | 118 mg (130% DV)Vitamin C (from acerola and ascorbic acid) | Tablet | 7.0 |
 | 62 mg vitamin CVitamin C and B vitamins (B3, B5, B6, B12) | Stick pack | 7.0 |
 cGMP facility | 90 mg (100% DV)Vitamin C (from Lipid Metabolite Ascorbate) | Powder | 7.0 |
 NSF Contents Certified | 15 mg (17% DV)Vitamin C (as ascorbic acid) | Gummy | 6.8 |
 | 15 mg (17% DV)Vitamin C (as ascorbic acid) | Gummy | 6.6 |
 Informed Choice | 1,500 mg | Powder | 6.1 |
Amounts are per serving as printed on each label. “Not disclosed” usually means the ingredient sits inside a proprietary blend.
Questions people ask
How much vitamin c do studies use?
Adults need 90–120 mg a day, depending on sex and life stage. The upper limit for adults is 2,000 mg a day; more can cause digestive upset.
Which vitamin c supplement scores highest?
In our reviews, NOW Foods Vitamin C-1000 Sustained Release scores highest at 8.1/10, followed by AG1 Next Gen Daily Foundational Nutrition (7.3) and Viviscal Hair Growth Supplement (7.0). Scores weigh efficacy, quality, value, experience and transparency — not just the dose.
How much vitamin c is in these products?
It varies by product and serving size — for example NOW Foods Vitamin C-1000 Sustained Release (1,000 mg), AG1 Next Gen Daily Foundational Nutrition (500 mg), Viviscal Hair Growth Supplement (118 mg (130% DV)). The table above lists the amount per serving for every product we've reviewed.