Conclusion: The failure of vitamin C supplementation to reduce the incidence of colds in the general population indicates that routine vitamin C supplementation is not justified, yet vitamin C may be useful for people exposed to brief periods of severe physical exercise. Regular supplementation trials have shown that vitamin C reduces the duration of colds, but this was not replicated in the few therapeutic trials that have been carried out. Nevertheless, given the consistent effect of vitamin C on the duration and severity of colds in the regular supplementation studies, and the low cost and safety, it m
Vitamin C side effects
Across 928 first-hand reports, people mentioned a side effect 21 times (about 2 per 100 reports). The most common: kidney stones, stomach issues, insomnia. User reports show what people notice — they can't tell you whether Vitamin C is safe for you.
Reported side effects
kidney stones6
stomach issues5
insomnia2
bone pain2
kidney stone2
diarrhea2
copper depletion1
brain zaps1
What got worse for some people
In their own words
“I've been trying to calm it down with Phopshatidylserine, Vit C, and Magnesium, assuming it's something to do with Cortisol or Adrenaline. But I can't seem to get it to go away.”
“I took 2500mg of Vitamin C a day for a few days, and had the worst heart palpitations, sleep apneas, bone pains and bleeding gums I've ever experienced.”
Is Vitamin C safe? What the research covers
AResearch: Strong738 meta-analyses · 2,072 randomized trials on PubMed
Cochrane Database Syst Rev · 2013
Vitamin C for preventing and treating the common coldMol Nutr Food Res · 2024
Micronutrients and Androgenetic Alopecia: A Systematic ReviewConclusion: Deficiencies or imbalances in specific vitamins and minerals, especially vitamin B, vitamin D, Fe, Se, and Zn are involved in the pathogenesis of AGA and may represent modifiable risk factors for the treatment and prevention of this condition.
Clin Nutr · 2022
ESPEN micronutrient guidelineConclusion: This guideline should enable addressing suboptimal and deficient status of a bundle of MNs in at-risk diseases. In particular, it offers practical advice on MN provision and monitoring during nutritional support.