Vitamin C (ascorbic acid) is a water-soluble vitamin and potent antioxidant essential for immune function, collagen synthesis, and iron absorption. Accurate quantification is required for nutritional labeling, quality control of fortified foods, and supplement stability testing. Ovalab provides accredited vitamin C testing using HPLC.
Key Facts About Vitamin C (Ascorbic Acid)
- EU NRV: 80 mg per day (Annex XIII, Regulation 1169/2011).
- Forms: L-ascorbic acid (reduced) and L-dehydroascorbic acid (oxidized). Total vitamin C includes both.
- ISO standard: ISO 20635:2018 specifies HPLC-UV for vitamin C in infant formula and adult nutritionals.
- Claims: “Source of vitamin C” requires ≥ 15% NRV (12 mg) per 100 g; “high in vitamin C” requires ≥ 30% NRV (24 mg) per 100 g (Regulation 1924/2006).
- Stability: Vitamin C is highly sensitive to heat, light, and oxidation — proper sample handling is critical for accurate results.
Testing Methods at Ovalab
Ovalab determines vitamin C using HPLC with UV detection. For total vitamin C (including dehydroascorbic acid), a reduction step is applied. Testing under ISO/IEC 17025:2018 (ČIA, Certificate 537/2025) and GMP (SÚKL 74726/2023).
Frequently Asked Questions
What is the difference between ascorbic acid and total vitamin C?
Ascorbic acid (L-ascorbic acid) is the reduced, active form. Total vitamin C also includes dehydroascorbic acid (oxidized form). For accurate labeling, total vitamin C should be determined.
What is the EU NRV for vitamin C?
80 mg per day (Annex XIII, Regulation 1169/2011). ‘Source of vitamin C’ requires ≥ 12 mg per 100 g (15% NRV).
Why is vitamin C difficult to analyze?
Vitamin C degrades rapidly with heat, light, oxygen, and alkaline conditions. Samples must be stabilized with acid (e.g., metaphosphoric acid) immediately to prevent oxidative losses.
Which products typically require vitamin C testing?
Fruit juices, fortified beverages, dietary supplements, infant formulas, multivitamins, and pharmaceutical products. Also used in shelf-life studies.
Can Ovalab test both natural and added vitamin C?
Ovalab’s HPLC method quantifies total L-ascorbic acid regardless of source. Natural and synthetic vitamin C are chemically identical and indistinguishable by analysis.