Key Functions
Vitamin C (ascorbic acid) performs numerous critical roles:
- Collagen synthesis: Cofactor for prolyl hydroxylase and lysyl hydroxylase—mandatory for stable collagen triple helix formation
- Antioxidant: Scavenges free radicals; regenerates oxidised vitamin E and glutathione
- Immune function: Accumulates in neutrophils and lymphocytes at 80× plasma concentration; essential for immune cell killing ability
- Iron absorption: Converts ferric (Fe³⁺) to ferrous (Fe²⁺) iron for absorption—critical for Indian vegetarians
- Carnitine synthesis: Required cofactor for ALCAR production
- Neurotransmitter synthesis: Cofactor for dopamine-β-hydroxylase (norepinephrine from dopamine)
Absorption: Why Dose Matters
Vitamin C absorption is dose-dependent and saturates rapidly. At 200mg: ~70–80% absorbed. At 1000mg: ~50% absorbed; remainder causes diarrhoea (bowel tolerance). This is why split dosing is critical at higher intake:
| Daily Dose | Strategy | Best For |
|---|---|---|
| 200–500mg | Once daily with meal | Maintenance, daily immune support |
| 500–1000mg | Split: 250–500mg twice daily | Collagen synthesis, antioxidant support |
| 1000–2000mg | Split 3–4 times/day | Acute illness, high oxidative stress periods |
| Liposomal 500–1000mg | Once or twice daily | Equivalent to 2–4g standard C in plasma effect |
Iron deficiency anaemia affects approximately 50% of Indian women and 25% of men. Indian diets provide predominantly non-heme iron (from lentils, spinach, fortified foods) which has only 2–10% absorption. Vitamin C converts non-heme iron to the more absorbable ferrous form and prevents its inhibition by phytates (abundant in Indian wheat and lentil-based diets). Taking 100–200mg vitamin C with iron-rich meals (dal, green leafy vegetables) increases iron absorption by 3–4×. This is the simplest, cheapest nutrition intervention for iron deficiency in India.
Frequently Asked Questions
What are the benefits of high-dose vitamin C in India?
High-dose vitamin C (500–2000mg/day) significantly enhances immune cell function, supports collagen production for skin/joints/gut, increases iron absorption from plant foods (critical for vegetarians), and provides potent antioxidant protection against India's high pollution burden. The combination of mandatory collagen synthesis cofactor role and immune support makes vitamin C one of the highest-value, lowest-cost supplements available.
Liposomal vitamin C vs regular ascorbic acid?
Liposomal C achieves 3–5× higher plasma concentrations than equivalent standard C by bypassing intestinal absorption limits. For daily maintenance: standard ascorbic acid 500mg twice daily is cost-effective. For therapeutic applications (immune, anti-aging, post-illness recovery): liposomal C at 500–1000mg justifies its higher cost (₹1500–3000/month in India vs ₹200–400/month for standard C).
Why does collagen need vitamin C?
Prolyl and lysyl hydroxylase enzymes require vitamin C as a cofactor to hydroxylate proline and lysine in procollagen. Without this hydroxylation, collagen triple helices are unstable and fall apart. Take 50–100mg vitamin C simultaneously with collagen supplements. Amla (Indian gooseberry) powder is an excellent natural vitamin C source—1g amla powder contains approximately 500mg vitamin C.
How much vitamin C is too much?
UL is 2000mg/day. GI side effects (diarrhoea) occur above bowel tolerance—typically 1–3g/day for most people. Those with kidney stones (oxalate type) should limit to 500mg/day. During acute illness, 2–4g/day in divided doses is safe. Above 2g/day: consult a doctor if you have kidney disease, haemochromatosis, or G6PD deficiency.