Citric acid is an organic acid found naturally in citrus fruits and is widely used in food, cosmetics, personal care, forestry, dairy, pharmaceutical, electroplating and cleaning products. The FDA says citric acid is "generally recognized as safe" in food and skin products and has many health benefits. It has antioxidant, antiseptic and antimicrobial properties that help protect the body from free radical damage, protect the heart, prevent cancer and kidney stones; keep foods fresh and enhance other flavours; and kill bacteria and mould.

However, citric acid may cause the following problems:

(1) Skin irritation. When it comes into contact with your skin for a long time, it can cause stinging, swelling or hives.

(2) Eye pain. If citric acid gets into your eyes, it can burn. If this happens, rinse with water for several minutes. If you wear contact lenses, remove them as soon as possible.

(3) Dental problems. Drinks and candies containing citric acid can wear away the enamel (outer layer) of your teeth. This can make your teeth more sensitive, cause them to turn yellow, and make you more likely to get cavities.

(4) Stomach upset. If you take medications containing citric acid by mouth, you may experience side effects such as nausea or vomiting.

Most importantly, medications containing citric acid may cause serious side effects such as:

• Confusion

• Lightheadedness

• Chest pain

• Rapid heartbeat

• Pain

• Tingling or numbness in the hands or feet

• Fatigue

One report found that four people experienced joint pain, swelling and stiffness, muscle and stomach pain, and shortness of breath after consuming foods containing artificial citric acid. Serious side effects of citric acid and sodium citrate include muscle twitches or cramps, swelling or weight gain, fatigue, mood changes, shortness of breath, increased heart rate, feelings of anxiety, black or bloody stools, extreme diarrhea, or seizures (convulsions).