The National Health Service and leading health experts are issuing a crucial warning to the millions of Britons who regularly take vitamin C supplements. While the vitamin is celebrated for its role in protecting cells and bolstering the immune system, particularly during the peak cold and flu season of January, excessive intake can lead to serious adverse effects. Individuals are being urged to cease supplementation immediately if they notice any of eleven specific symptoms, which range from gastrointestinal distress to indicators of kidney stones.
The Essential Role and Recommended Intake of Vitamin C
Vitamin C, a potent antioxidant, is vital for maintaining overall health. It safeguards cells from damage caused by free radicals, supports immune function, and is crucial for collagen production, which keeps skin, blood vessels, bones, and cartilage in good condition. Additionally, it enhances iron absorption and aids in wound healing. A deficiency can lead to scurvy, though this is rare in modern diets.
The NHS clearly states that adults aged 19 to 64 require 40mg of vitamin C daily. "You should be able to get all the vitamin C you need from your daily diet," the health body advises, noting that the vitamin cannot be stored in the body, necessitating daily intake through food. Good dietary sources include citrus fruits, peppers, strawberries, blackcurrants, broccoli, Brussels sprouts, and potatoes.
Recognising the Symptoms of Vitamin C Overdose
Taking large amounts of vitamin C, typically defined as more than 1,000mg per day from supplements, can trigger unpleasant and potentially harmful side effects. The NHS emphasises that while some symptoms may resolve once supplementation stops, others might require medical intervention.
Gastrointestinal Disturbances: Four Key Symptoms
High doses of vitamin C can overwhelm the body's absorption capacity, leading to an osmotic effect in the digestive system. This commonly results in four primary gastrointestinal symptoms:
- Diarrhoea
- Nausea
- Flatulence
- Stomach cramps
These issues typically subside if the dosage is reduced or supplementation is discontinued entirely.
Kidney Stone Risk: Seven Warning Signs
A more severe risk associated with excessive vitamin C intake is the development of kidney stones. The body converts surplus vitamin C into oxalate, which can form calcium oxalate stones in the kidneys. The NHS cautions, "Your body will absorb any Vitamin C in your diet and convert it to oxalate, which then goes on to form stones in your kidneys." Individuals with a history of kidney stones are often advised to avoid high-dose supplements.
While very small kidney stones may pass unnoticed, larger stones can cause significant discomfort. Be alert for these seven warning signs:
- Pain in the side of your abdomen or groin (men may experience pain in their testicles)
- A high temperature, or feeling hot, cold, or shivery
- Excessive sweating
- Severe pain that comes and goes
- Feeling sick or vomiting
- Blood in your urine
- Signs of a urine infection
Official Guidance and When to Seek Help
The Department of Health and Social Care reinforces that a varied and balanced diet should provide sufficient vitamin C for most people. If you choose to take supplements, it is crucial not to exceed safe limits. Taking less than 1,000mg daily is generally considered unlikely to cause harm.
If you are taking vitamin C supplements and experience any of the eleven symptoms listed above, you should stop taking them immediately and consult your GP. Avoid making any drastic changes to your diet or lifestyle without professional medical advice. Speak to your doctor if you have any health concerns or questions regarding supplementation.
This warning underscores the importance of using supplements judiciously and prioritising nutrient intake through whole foods, especially as the nation navigates the winter illness season.
