Not medical advice. I am a software engineer, not a physician. This page documents my own protocol and the research I read while building it. Talk to a qualified clinician before changing your supplementation, diet or any treatment. Lab reference ranges quoted here vary by laboratory and by individual.
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Vitamin C (ascorbic acid) is a water-soluble essential nutrient that humans cannot synthesize due to a mutation in the GULO gene that occurred roughly 60 million years ago. Unlike most mammals that produce their own vitamin C, we depend entirely on dietary intake or supplementation. This makes it one of the most critical supplements in any evidence-based protocol. The liposomal delivery form dramatically improves bioavailability by encapsulating ascorbic acid in phospholipid vesicles, bypassing the intestinal transporter bottleneck that limits standard vitamin C absorption to roughly 200 mg per dose.
Vitamin C is the essential cofactor for prolyl hydroxylase and lysyl hydroxylase — the enzymes that hydroxylate proline and lysine residues in procollagen. Without this hydroxylation, collagen molecules cannot form stable triple-helix structures, leading to weakened connective tissue, poor wound healing, and the classic signs of scurvy. This mechanism is why vitamin C is indispensable for skin integrity, joint health, and vascular wall strength.
As a potent electron donor, ascorbic acid neutralizes reactive oxygen species (ROS) including superoxide, hydroxyl radicals, and singlet oxygen. It regenerates vitamin E (alpha-tocopherol) from its oxidized form, maintaining the lipid-soluble antioxidant defense in cell membranes. This makes vitamin C a central node in the body's antioxidant network, protecting DNA, proteins, and lipids from oxidative damage.
Vitamin C reduces ferric iron (Fe3+) to ferrous iron (Fe2+) in the gut, which is the form absorbed by the divalent metal transporter 1 (DMT1). Taking vitamin C with iron-rich meals or iron supplements can increase non-heme iron absorption by 2-3 fold. This is particularly important for those with iron deficiency or plant-based diets.
Vitamin C accumulates in immune cells (neutrophils, monocytes, lymphocytes) at concentrations 10-100x higher than plasma levels. It supports the oxidative burst — the mechanism by which phagocytes kill pathogens. It also enhances neutrophil chemotaxis, lymphocyte proliferation, and natural killer cell activity. During infection, vitamin C stores are rapidly depleted, which is why supplementation during illness has measurable benefits.
Why liposomal? Standard oral vitamin C relies on the sodium-dependent vitamin C transporter (SVCT1) in the intestine, which saturates at roughly 200 mg per dose. Liposomal encapsulation allows the vitamin C to be absorbed via lipid-mediated pathways, achieving plasma levels comparable to IV administration without gastrointestinal distress.
| Parameter | Detail |
|---|---|
| Product | Dr. Mercola Liposomal Vitamin C |
| Dose | 1,000 mg (2 capsules of 500 mg each) |
| Timing | With breakfast |
| Form | Liposomal ascorbic acid in phospholipid vesicles |
| Duration | Daily, ongoing |
See the full supplement stack for timing relative to other supplements and meals.
The following studies form the evidence base for vitamin C supplementation in this protocol:
Carr, A. C., & Maggini, S. (2017). Vitamin C and immune function. Nutrients, 9(11), 1211. — Comprehensive review showing vitamin C accumulates in phagocytic cells at 10-100x plasma levels, enhances chemotaxis, phagocytosis, and microbial killing. Supplementation reduces cold duration by 8-14%. PubMed 29099763
Gopi, S., & Balakrishnan, P. (2021). Evaluation of the bioavailability of liposomal vitamin C. J Liposome Res, 31(1), 43-49. — Demonstrated that liposomal vitamin C achieves 1.5-1.77x higher plasma concentrations than non-liposomal forms, with significantly greater AUC (area under the curve). PubMed 28353648
Padayatty, S. J., et al. (2003). Vitamin C as an antioxidant. J Am Coll Nutr, 22(1), 18-35. — Established vitamin C as the most effective aqueous-phase antioxidant in human plasma, capable of scavenging superoxide, hydroxyl, and peroxyl radicals, and regenerating alpha-tocopherol. PubMed 11375434
These tests track inflammation and iron status — the two areas most directly influenced by vitamin C supplementation.
| Test | Why It Matters | Link |
|---|---|---|
| CRP (C-Reactive Protein) | Vitamin C reduces systemic inflammation; CRP tracks this effect objectively. Optimal: below 1.0 mg/L | Lab Tests |
| Iron Panel (Ferritin, Serum Iron, TIBC) | Vitamin C enhances non-heme iron absorption 2-3x; monitor to ensure iron does not rise excessively if supplementing both | Lab Tests |
A 2025 review in the International Journal of Molecular Sciences examined vitamin C's role in autoimmune and immune-mediated diseases including multiple sclerosis, rheumatoid arthritis, Sjögren's disease, type 1 diabetes, Hashimoto's thyroiditis, and Crohn's disease. The review concluded that vitamin C deficiency is common in many of these conditions and may contribute to increased oxidative stress and immune disequilibrium. A January 2025 systematic review evaluating alternative vitamin C formulations found that calcium ascorbate EC showed favorable impacts on immune parameters and was associated with fewer colds and shorter duration of severe symptoms vs. placebo. High-dose vitamin C has re-emerged as a promising anti-cancer therapy: multiple 2025–2026 preclinical studies demonstrated selective anti-tumor effects through pro-oxidative cytotoxicity, anti-cancer epigenetic regulation, and immune modulation. A June 2025 comprehensive review detailed vitamin C's roles in infectious diseases and the immune system's response mechanisms.
Dr. Mercola Liposomal Vitamin C — 1,000 mg, 180 capsules (500 mg per capsule). Price: $22.26. Buy on iHerb