Weak evidence · Vitamins & minerals
High-dose vitamin C
Sold against colds and for recovery
Weak evidence
Mostly small studies, animal trials or conflicting results. Not worth your money as a foundation.
A Cochrane review (2013) found that daily vitamin C does not lower the number of colds in the general population, but does modestly shorten their duration. In people under short bouts of extreme physical stress, such as marathon runners and skiers, it halved the risk of a cold. High doses started after the first symptoms had no consistent effect.
- Dosage
- No benefit of gram doses shown; the studies used at least 200 mg per day
- Timing
- —
- Approx. price
- €3–8 per month
Watch out
In one trial with 1000 mg of vitamin C and 235 mg of vitamin E per day, markers of mitochondrial biogenesis rose less after endurance training, with no difference in the performance tests. Caution with high doses of antioxidants around endurance training is therefore sensible.
Frequently asked questions about supplements
How much High-dose vitamin C per day?
No benefit of gram doses shown; the studies used at least 200 mg per day
Does High-dose vitamin C really work?
Weak evidence. Mostly small studies, animal trials or conflicting results. Not worth your money as a foundation.
What does High-dose vitamin C cost?
€3–8 per month
Basics first, then the tub
Supplements are called supplements because they add to something. Sleep, a protein intake that hits your protein calculator , a programme where you lift progressively heavier and enough food together do a hundred times more than the best-researched item on this list. Once those are in place, creatine, caffeine and vitamin D in winter are the three you can spend money on with a clear conscience — for less than ten euros a month combined.
Sources
- Hemilä H, Chalker E (2013). Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev CD000980. (Cochrane review)
- Paulsen G et al. (2014). Vitamin C and E supplementation hampers cellular adaptation to endurance training in humans: a double-blind, randomised, controlled trial. J Physiol 592(8):1887-1901. (randomized trial)
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Last updated: October 2026
This page summarises scientific research and is not medical advice. If you take medication, are pregnant or have a liver, kidney or thyroid condition, discuss supplements with your doctor or pharmacist — even the innocent-looking ones.
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