Vitamin overdose

Excessive use of nutritional supplements can have a damaging effect on health

Gu Ai is a 27-year-old woman who takes great care in her appearance. Unhappy with a slight suntan she got over the summer, Gu decided to make up for it with health supplements.

"I heard that taking vitamin C and vitamin E was a good way to make your skin turn white because they act as antioxidants and anti-aging products," said Gu, who bought several bottles of vitamin C and vitamin E pills and started taking two pills of both daily.

"I like to eat sour food, so I couldn't help but take several extra pills of vitamin C everyday which are sour and sweet, just like candy," said Gu. Then one day after Gu had consumed nearly 10 pills of the vitamin, she started having severe bouts of vomiting and diarrhea.

Gu went to the hospital with what she thought was enterogastritis, a medical condition that causes inflammation of the stomach and vomiting. After blood test, however, the doctor informed Gu that she had acute intoxication caused by an overdose of vitamin C pills.

Although vitamin supplements in the form of pills and health drinks are commonly recognized to be nourishing, many are unaware of the fact that it's risky to overuse. An online survey on common medicine knowledge conducted by the Chinese Pharmaceutical Association showed that 36 percent of those surveyed did not know the correct way to take vitamins.

Pharmacist Li Yili has to continually warn his patients of the risk of a vitamin overdose. "Many people have come to me for complex vitamin prescriptions. They want to improve their health, without knowing that it can be rather harmful to their health."

Li explains that an overdose at one time can trigger diarrhea and abdominal distension, while consuming continuous overdoses over a sustained period can lead to gout, kidney stones and other health defects. "Women of child-bearing age who take an overdose of vitamin C for a sustained period may suffer from a fertility decrease," added Li.

The continuous overtaking of vitamin E can also lead to problems such as the thickening of one's blood, warns Li. "If women take it together with drugs containing female hormone, the danger of thrombophlebitis [a blood clot] greatly increases," he said.

Li said vitamin C supplements usually contain 500 to 1,000 milligrams per pill, while the recommended daily intake for vitamin C is only 75 milligrams for adult women, and 90 milligrams for adult men, according to the American Department of Agriculture.

Nutritionist Yang Wenjiao regularly encounters clients consuming large amounts of vitamins. "Some people overtake vitamin C and E to improve their looks, while others take multivitamins even though they are only lacking in one kind of vitamin type."

Only people with irregular diet patterns, such as those who are on diets to lose weight, pregnant women or picky eaters, need to take vitamin supplements, and that should only be on the recommendation of a medical professional.

A balanced diet provides all the daily vitamins one needs without any risk of damaging their health, said Yang. "The consumption of natural vitamins through food seldom leads to a vitamin overdose because natural vitamins can be easily broken down through the body's metabolic pathways, while the pills cannot," she said.

The best way to take natural vitamins, according to Yang, is to keep a balanced and diverse diet, while eating more coarse grains and beans.

"A healthy person should eat about 500 grams of mixed vegetables, and 200 to 400 grams of fruits everyday," she explained. "It is best if one can eat about 20 to 30 kinds of different food each day to balance the vitamin content."