Vitamin C is a water-soluble essential micronutrient that humans cannot synthesise and must obtain through their diet. ¹ Known for its antioxidant properties and role in immune function, vitamin C is an important nutrient to consider when developing fortified food and beverage products. For fruit juice manufacturers, adding vitamin C can be one way to enhance a product's nutritional profile. However, developing vitamin C-fortified fruit juice involves more than simply adding the nutrient to a beverage.
Manufacturers must consider the scientific evidence behind vitamin C’s health benefits, the amount present in the finished product, and the regulatory requirements for fortification and health claims. As these requirements vary across markets, understanding local regulations is essential for developing compliant products and communicating their nutritional benefits responsibly. This article explores vitamin C requirements across six countries: Indonesia, Malaysia, the Philippines, Thailand, China and Sri Lanka. Find out more below.
How Vitamin C Supports Normal Immune Function
Vitamin C supports normal immune function. Immune cells, particularly neutrophils and T-lymphocytes, accumulate vitamin C and depend on it for normal function.²
In phagocytes, vitamin C supports chemotaxis, phagocytosis and microbial killing. It also helps maintain epithelial barrier function and supports B-cell and T-cell differentiation.²
Inadequate vitamin C intake can compromise immune function, while infection can accelerate vitamin C depletion.¹
The European Food Safety Authority (EFSA) established a Population Reference Intake of 110 mg/day for men and 95 mg/day for women, corresponding to a plasma ascorbate concentration of approximately 50 μmol/L.³ These values provide nutritional context for vitamin C content in product formulation.
Vitamin C and the Common Cold: What Does the Evidence Show?
Scientific research on vitamin C has investigated its potential effects on the incidence, duration and severity of the common cold. However, the findings vary depending on the population studied and the outcome measured.
A Cochrane review involving 11,306 participants found that regular vitamin C supplementation at doses of 200 mg or more per day did not meaningfully reduce common-cold incidence in the general population (RR 0.97, 95% CI 0.94–1.00).⁴ However, among groups exposed to extreme physical stress, including marathon runners, skiers and soldiers in subarctic conditions, vitamin C supplementation reduced cold incidence by 52% (RR 0.48, 95% CI 0.35–0.64).⁴
The same review found that regular supplementation reduced the duration of common colds by approximately 8% in adults and 14% in children.⁴ In addition, a 2023 meta-analysis reported a 15% reduction in common-cold severity compared with placebo (95% CI 9–21%).⁵
From a regulatory perspective, this distinction matters when developing product claims. Evidence that vitamin C contributes to normal immune function does not automatically
