The number on the vitamin C label was set to stop scurvy, not to make you thrive

A quiet study out of Canterbury found that 62% of midlife New Zealand adults are walking around with inadequate vitamin C levels. Inadequate, not deficient. They had enough to keep their teeth in, not enough to optimise their immune system, collagen production, or cognitive markers.

The CHALICE cohort, run by the University of Otago Christchurch, screened 404 adults from the local population. The result is one of the most uncomfortable numbers in NZ nutrition research, and almost nobody outside the field has heard it.

So if most New Zealanders are not even hitting the basic adequate threshold, the next question is the obvious one. What is the right amount?

This is where the conversation usually breaks.

One camp says the RDI of 45 to 90mg is plenty, and anything above it is “expensive urine.” The other camp pushes 1000mg pills and claims any number you can swallow is fine. Both groups are arguing about a number that was never designed for what most people want vitamin C to do.

The Recommended Dietary Intake exists to prevent scurvy. Not to optimise immune function. Not to maximise collagen cross-linking. Not to support the antioxidant load of a 21st-century life.

So what is the right amount?

This is not a fringe view. Dr Anitra Carr, who leads the Nutrition in Medicine Research Group at the University of Otago Christchurch and is one of the most cited vitamin C researchers in the world, has spent over a decade publishing on this exact gap. Her group’s published work recommends 120 to 200mg per day as the intake range needed to reach plasma saturation — the level at which tissue uptake is maximised and the body actually has what it needs for the non-scurvy jobs.

200mg per day is more than double the Australian and NZ RDI for adult men.

What actually happens when you mega-dose

The other thing the research is clear about, and that the supplement industry tends to be quiet on, is what happens with mega-dosing. Once plasma reaches saturation, additional ascorbic acid is excreted in urine. This is not a problem with synthetic vitamin C specifically — it is a feature of how the body handles ascorbate full stop. Whether you take 1000mg of synthetic powder or 1000mg of mango-based extract, the kidneys will clear the surplus. So the “expensive urine” critique is partly fair: a single 1000mg hit is far more than your body can use in one sitting.

What matters more is sustained intake. Vitamin C is water-soluble and has a relatively short half-life in the blood, which is why splitting a daily dose — or taking it through food matrices that release more slowly — produces better tissue concentrations than a single megadose. Carr’s group has demonstrated this directly in NZ trials using kiwifruit, where divided daily doses produced sustained increases in plasma, leukocyte, and skeletal muscle vitamin C.

The case for wholefood-sourced vitamin C

This is the case for wholefood-sourced vitamin C, properly framed. It is not that synthetic ascorbic acid is broken. It is that food matrices contain bioflavonoids, fibre, and other co-factors that slow absorption and extend the window during which vitamin C is bioavailable.

One Otago-linked animal study using a vitamin C-deficient mouse model found significantly higher tissue ascorbate levels from kiwifruit than from synthetic ascorbate at equivalent doses, suggesting synergistic activity of the whole fruit. Human studies show more modest differences, but the direction is consistent: whole-food sources behave more like a steady drip than a flash flood.

Where Vitus Wholefood Vitamin C fits

Vitus Vitamin C is sourced from Acerola Berry, Camu Camu, and Kakadu Plum, three of the most vitamin C-dense fruits in the world. There is no synthetic ascorbic acid in the jar. The label notes it provides over ten times the RDI per 4g serve, which is one teaspoon.

Importantly, it is delivered alongside the bioflavonoids and plant co-factors that exist in those fruits naturally, plus elderberry juice powder for additional polyphenol load and flaxseed flour for fibre. None of that is decoration — those are the co-factors that slow absorption and extend the bioavailable window. It’s taken stirred into liquid or food, never heated, which preserves the ascorbate.

Vitus · Vegan Wholefood

Vitus Vitamin C Powder

• Acerola Berry, Camu Camu & Kakadu Plum — no synthetic ascorbic acid
• Over 10× the RDI per 4g (one teaspoon) serve
• With natural bioflavonoids, elderberry polyphenols & flaxseed fibre
• 100% recyclable jar & lid

Shop Vitus Vitamin C

The honest version of the conversation

If you are the kind of person who has been taking 1000mg ascorbic acid tablets at the first sign of a sniffle and wondering why it doesn’t feel like it’s doing anything, the answer is probably the dosing rhythm. A single large hit clears fast. A teaspoon of wholefood vitamin C taken daily, especially across winter, lands closer to what the research actually supports as effective.

If you have never bothered with vitamin C supplementation because you assumed your diet was covering it, the CHALICE numbers are worth sitting with. 62% of NZ midlife adults are not hitting adequate levels, even on a diet that includes fruit. Fresh produce loses vitamin C in transit, storage, and cooking. A concentrated wholefood source closes that gap without the megadose-and-flush cycle of synthetic pills.

The honest version is this: the RDI is the floor, not the ceiling. The ceiling, as defined by saturation studies, sits somewhere around 200mg per day, taken consistently. Wholefood sources hold that concentration in the body longer than synthetic isolates do, especially when paired with bioflavonoids. And most New Zealanders, by Otago’s own count, are below the floor.