What are the side effects of vitamin C?
Mar 09, 2025
Source: Cainiu Health
Dr. Bai Hongmei
Introduction
Under normal circumstances, vitamin C is commonly available in dosage forms such as tablets, capsules, and effervescent tablets. Possible side effects may include diarrhea, nausea and vomiting, stomach cramps, urate stones, hemolysis, etc. To avoid side effects of vitamin C tablets, it is recommended to take them according to the recommended usage and dosage, and avoid excessive intake. Additionally, be mindful of drug interactions and medication use in special populations.
Generally, vitamin C is available in various dosage forms such as tablets, capsules, and effervescent tablets. Its potential side effects may include diarrhea, urinary system problems, allergic reactions, changes in urine, and excessive iron absorption. A detailed explanation is as follows:
1. Diarrhea
Vitamin C digestion and absorption in the gastrointestinal tract may increase the digestive burden and cause diarrhea. Long-term excessive intake may also induce gastrointestinal diseases such as gastritis and gastric ulcers.
2. Urinary System Problems
After metabolism in the body, vitamin C produces oxalic acid. Excessive intake of vitamin C increases oxalic acid production. When oxalic acid combines with calcium in the kidneys, calcium oxalate stones may form, increasing the risk of kidney stones. Additionally, large amounts of vitamin C may affect the pH of urine, making it more acidic and creating conditions favorable for bacterial growth, which may lead to urinary tract infections.
3. Allergic Reactions
Some individuals with particular constitutions may experience allergic reactions after taking vitamin C, manifesting as red, shiny skin accompanied by itching, stinging sensations, rashes, or skin irritation.
4. Changes in Urine
Excessive intake of vitamin C elevates its concentration in the body. The excess vitamin C is filtered by the kidneys and excreted in the urine, potentially making the urine more acidic and possibly causing cloudy urine.
5. Excessive Iron Absorption
Vitamin C promotes iron absorption. Under normal circumstances, this helps prevent iron-deficiency anemia. However, if large amounts of vitamin C are consumed together with iron-rich foods or iron supplements, it may lead to excessive iron absorption. Accumulated iron can damage organs such as the liver and heart, impairing their normal functions.
To avoid side effects from vitamin C tablets, it is recommended to follow the prescribed dosage and administration instructions and avoid excessive intake. Additionally, be mindful of drug interactions and special populations such as pregnant women, lactating women, and children, who should use vitamin C cautiously under a doctor's guidance. If side effects from excessive intake occur, seek timely medical diagnosis and treatment.
