Overdosing on Vitamin C Carries Hidden Risks, Doctors Warn

While many believe that consuming extra Vitamin C is harmless due to its water-soluble nature, a doctor warns of hidden dangers associated with high doses. Dr. Hsieh Ping-hsien, a neurosurgery attending physician at National Yang Ming Chiao Tung University Hospital, highlights that exceeding the recommended intake can lead to serious health consequences.

The daily recommended intake for adults is approximately 100mg, with a safe upper limit of 1000mg. Consuming over 2000mg daily can trigger various adverse effects. These include severe gastrointestinal distress, such as nausea, vomiting, abdominal pain, and frequent diarrhea, with some individuals experiencing over ten bowel movements a day.

Beyond digestive issues, excessive Vitamin C intake poses a significant risk of kidney stones. The body metabolizes Vitamin C into oxalate, which can bind with calcium to form calcium oxalate stones. This risk is often overlooked by those taking high-dose supplements long-term. Additionally, individuals may experience persistent headaches, dizziness, insomnia, and increased irritability due to the impact on iron absorption and abnormal blood oxalate levels.

Paradoxically, extremely high doses of Vitamin C can reverse its antioxidant effects, promoting oxidative stress and accelerating cell damage. A lesser-known danger is rebound scurvy, which can occur after abruptly stopping high-dose supplements. This condition temporarily impairs the body's ability to absorb Vitamin C from normal dietary sources, leading to symptoms like gum bleeding, joint pain, and delayed wound healing.