Vitamin C
Vitamin C is a low-risk supplement with an RDA of 90 mg and a tolerable upper intake level (UL) of 2000 mg per day according to NIH/NASEM standards. EFSA lists a RDA of 110 mg but has not established a formal UL; NHMRC lists a RDA of 45 mg but has not established a formal UL. It has 3 known interactions with other supplements including collagen, iron, quercetin. Use NutriAudit to check if your supplement stack keeps this ingredient within safe limits.
Quick take
Vitamin C sits in the Water-Soluble Vitamins category. This page consolidates 3 regional standards, and the limits vary enough that you should not treat one region's rule as universal.
It also has 3 known interactions, so the question is not just the label dose but whether the rest of your stack adds extra risk.
Taking multiple supplements? Check Vitamin C for overlap
If Vitamin C appears on two product labels, enter each daily amount and check the combined label total.
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Regional Reference Values
| Region | Organization | RDA | Upper Limit (UL) | Unit |
|---|---|---|---|---|
| 🇺🇸 United States | NIH ODS, NASEM DRI | 90 | 2000 | mg |
| 🇪🇺 Europe | EFSA | 110 | Not established | mg |
| 🇦🇺 Australia | NHMRC | 45 | Not established | mg |
Europe: EFSA has not established a tolerable upper intake level for vitamin C.
Australia: NHMRC did not establish a formal UL for vitamin C.
RDA = Recommended Daily Allowance (adequate intake for most adults). UL = Tolerable Upper Intake Level; some authorities have not established one.
Known Interactions
Vitamin C enhances collagen synthesis (positive interaction).
Taking vitamin C with collagen is beneficial.
Vitamin C enhances iron absorption (positive interaction).
Taking together is beneficial.
Vitamin C enhances quercetin absorption (positive interaction).
Taking quercetin with vitamin C is beneficial.
How to use this page
First match your product label against the dose table above, then check whether the known interaction list includes anything in your current stack.
If you are taking multiple supplements, the safest approach is usually to audit the whole stack instead of judging a single bottle in isolation.
Frequently Asked Questions
How much Vitamin C is too much?
NIH ODS, NASEM DRI lists a formal upper limit (UL) of 2000mg per day for Vitamin C. Other regions may use a different value or have no established UL.
What is the recommended daily dose of Vitamin C?
The RDA for Vitamin C is 90mg per day for most adults. This amount is sufficient to meet the needs of 97-98% of healthy individuals.
Does Vitamin C interact with other supplements?
Yes, Vitamin C has 3 known interactions with other supplements. Vitamin C enhances collagen synthesis (positive interaction).
Are you taking Vitamin C?
Check if your supplement stack keeps Vitamin C within safe limits.
Audit My SupplementsDisclaimer: NutriAudit is a decision-support tool designed to help you review your supplement stack for potential duplicate, conflicting, or excessive ingredients. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making changes to your supplement routine, especially if you are pregnant, nursing, taking medications, or have a medical condition.
Uses cited public reference data where the current dataset has a verified entry.