Archive · 12 Jan 2026
Vitamin C Supplements May Increase Kidney Stone Risk
Vitamin C is important for our body, but taking too many supplements can be risky.
A woman named Saku Shukla shared her story of how taking too much vitamin C led to kidney stones.
Doctors say that high doses of vitamin C can turn into something called oxalate, which can combine with calcium and form stones in the kidneys.
This risk is higher for men and people who already have a history of kidney stones or certain health conditions.
To stay safe, it's better to get vitamin C from foods like fruits and vegetables instead of supplements.
Drinking lots of water and eating a balanced diet can also help prevent kidney stones.
Excess vitamin C from supplements can increase the risk of kidney stones by converting to oxalate.
High doses of vitamin C (over 700-1,000 mg/day) significantly raise urinary oxalate levels.
Men are at a higher risk due to more efficient conversion of vitamin C to oxalate.
Natural food sources of vitamin C are safer as they provide fiber that moderates absorption.
Increasing hydration and maintaining a balanced diet can help prevent kidney stone formation.
- Who
- Individuals taking high-dose vitamin C supplements, especially men
- What
- Increased risk of kidney stones due to excess vitamin C intake
- When
- When consuming more than 700-1,000 mg of vitamin C daily
- Where
- Global concern, applicable to anyone taking vitamin C supplements
- Why
- Excess vitamin C is metabolized into oxalate, which combines with calcium to form kidney stones
- Vitamin C Function
- Tissue repair, collagen formation, wound healing, immune function, antioxidant
- Vitamin C Sources
- Citrus fruits, berries, peppers, broccoli, supplements
- Risk Threshold
- More than 700-1,000 mg/day
- Safe Dosage
- Below 500-1,000 mg/day
- High-Risk Groups
- Men, individuals with history of stones, dehydration, high-protein diets, or obesity
- Prevention Tips
- Increase hydration, balanced diet, monitor risk factors