I want to share something I've been doing since I was eleven years old. It started with a tennis coach (a genuinely well-read man who seemed always to know things that other adults didn't). I came down with pfeiffer (glandular fever, mononucleosis) and missed weeks of training. When I finally saw him again, he said something I have never forgotten: 'Take vitamin C. High doses. Every day. It will help you work through this faster and prevent the next one.'

I was eleven. I had no framework for evaluating that advice scientifically. But I trusted him, I did what he said, and I recovered faster than anyone expected. That experience planted a seed of curiosity about immune support that has never stopped growing.

Why Vitamin C Is Central to Immune Function

Vitamin C (ascorbic acid in its synthetic form; a complex of compounds in its whole food form) is perhaps the single most important micronutrient for immune function. Here's the biology:

Vitamin C accumulates in immune cells to concentrations many times higher than in the blood plasma (neutrophils, for example, concentrate vitamin C up to 100-fold compared to plasma levels). When the immune system is actively responding to a threat, it burns through vitamin C at a remarkable rate (vitamin C is consumed in the production of reactive oxygen species used to kill pathogens, and in the regulation of the inflammatory response that follows).

This is why blood vitamin C levels plummet during acute infection even in people who are normally sufficient (the immune response depletes it rapidly). Maintaining high-quality, highly bioavailable vitamin C intake is one of the most direct and well-evidenced strategies for supporting immune resilience.

The Critical Distinction: Ascorbic Acid vs Whole Food Vitamin C

Most vitamin C supplements on the market contain ascorbic acid (a synthetic isolate manufactured industrially from glucose through a multi-step fermentation and chemical process). Ascorbic acid is chemically identical to the ascorbic acid portion of natural vitamin C, and it does provide some benefit.

But natural vitamin C is not a single compound. It is a complex system: ascorbic acid plus bioflavonoids (including rutin, hesperidin, and quercetin), tyrosinase (a copper enzyme), vitamin P, and other cofactors that exist naturally alongside ascorbic acid in whole food sources. These cofactors significantly enhance the absorption, tissue retention, and biological activity of vitamin C. Isolated ascorbic acid without its natural cofactors behaves differently in the body (it's absorbed faster but also eliminated faster, without the sustained tissue saturation that whole food vitamin C provides).

The Most Vitamin C-Dense Foods on Earth

Acerola Cherry

Acerola (Malpighia emarginata) is the richest known plant source of natural vitamin C, containing up to 65 times more vitamin C per gram than an orange. More importantly, acerola provides the full vitamin C complex (ascorbic acid, bioflavonoids, and cofactors) in natural proportions. It is the source we prioritise.

Camu Camu

Camu camu (Myrciaria dubia) grows wild in the Amazon floodplains of Peru and Brazil. It is one of the richest known sources of natural vitamin C on earth, with a particularly high bioflavonoid content alongside the ascorbic acid. Traditional Amazonian communities have used it for generations for immune support and general vitality.

Amla (Indian Gooseberry)

Amla (Phyllanthus emblica) has been a central herb in Ayurvedic medicine for thousands of years (used specifically for immune support, vitality, and longevity). It contains a remarkable vitamin C complex that is unusually stable during processing (most vitamin C degrades rapidly with heat and oxidation; amla's tannin-bound form is considerably more stable).

My Daily Foundation for Immune Resilience

Daily Greens shot every morning (spirulina, chlorella, barley grass, moringa, wheatgrass, and baobab). Rich in iron (essential for immune cell proliferation), zinc, beta-glucans (from barley grass), and chlorophyll. The blend I made for Michael during chemotherapy (the green foundation).

Healing Turmeric. Turmeric and ginger provide daily anti-inflammatory and immune support. Chronic inflammation impairs immune function; reducing it frees immune resources for actual threats.

MultiVitamin. Whole food vitamins from real plant sources, filling the gaps that diet alone doesn't always close. Zinc from natural plant sources, iron from moringa and spirulina, folate from whole plant sources. Daily nutritional insurance.

There's a practical protocol I return to whenever I feel the early signs of something coming (that familiar prickle at the back of the throat, the subtle fatigue that precedes genuine illness). I increase my Daily Greens to three times daily, add fresh lemon and ginger to everything, prioritise sleep above everything else, and take high doses of whole food vitamin C from acerola and camu camu every few hours. This protocol, maintained consistently for 48 hours at the first sign of symptoms, has reliably shortened or averted every illness I've attempted to use it on for over a decade. The research on early intervention with high-dose vitamin C and immune-supportive plants is consistent with this experience.

But the daily foundation matters more than the acute intervention. A well-nourished immune system is a more resilient one, less likely to be overwhelmed by the pathogen load it encounters every day, more capable of mounting a rapid and effective response when it needs to. Building that foundation, consistently, is the real work.

→ Related: Food Is Information: What Functional Medicine Gets Right About Eating

→ Related: Barley Grass Benefits: The OG Superfood That's Been Quietly Working for Decades

Eat Plants. Feel Alive.

Xo Kristel & Michael

*These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.