Optimal Health Daily - Fitness and Nutrition 3267: Does Too Much Vitamin C Cause Side Effects? by Brianna Elliott with Healthline on Nutrient Overuse
15 snips
Jan 22, 2026 High doses of vitamin C can lead to surprising side effects like nausea and kidney stones. While it supports immunity, most people can meet their needs through a balanced diet. Excessive supplementation can increase the risk of iron overload in certain individuals. The tolerable upper limit is 2,000 mg, but it's rarely necessary to take megadoses. Instead, a daily intake of 90 mg for men and 75 mg for women is recommended, with adjustments for smokers. Natural food sources rarely cause excess, making them the better option.
AI Snips
Chapters
Transcript
Episode notes
Water-Soluble Vitamin Means Limited Storage
- Vitamin C is water-soluble so your body doesn't store it and excess is excreted in urine.
- This explains why dietary overdoses are rare and supplements pose the main risk.
Limit High-Dose Supplements To Prevent GI Upset
- Avoid taking more than 2,000 mg of vitamin C at once to prevent digestive upset.
- If you have gastrointestinal symptoms, reduce or stop supplements immediately.
Vitamin C Strongly Boosts Iron Absorption
- Vitamin C enhances non-heme iron absorption by binding to it and increasing uptake.
- This is helpful for plant-based eaters but risky for people with iron-overload conditions.