Man-made health Excessive vitamin intake brings adverse effects By Angela Yau Desiring a better health, peo- ple get extra nutrients from various vitamin supplements in addition to normal diet. “You can’t imagine the power of vitamins,” exclaimed Mr. George Chan, 19, of Lok Fu. Every morning, he takes a tablet of multi-vitamins and minerals. Mr. Hau Lun Bun, owner of Wui Cheong Dispensary in Mong Kok, said, “We may not obtain sufficient vitamins in our diet as we eat so many fast food. People can have a balanced diet if they use vitamin supplements. “The price of a bottle of vitamin tablets is about $100 to $200. People are willing to buy one as it is not expensive.” Many people believe that vitamins have magical effects on their health. However, they may have neglected the potential risks associated with excessive vitamin intake. While vitamin A is essential for having good eyesight, research has shown that large doses of vitamin A can do harm to pregnant women. Ms Susan Ho Suk San, a lecturer in the Department of Pharmacy at The Chinese University of Hong Kong, said, “Pregnant women should be very careful with their vitamin A intake. “Excessive intake of vitamin A, such as taking 3,000 micrograms, or insufficient dosage per day may lead to fetal malformation in which the foetus is badly-formed at an early stage.” Dr. Georgia S. Guldan, a lecturer in the Department of Biochemistry at The Chinese University of Hong Kong, said, “In general, prolonged overdoses of vitamin A may cause some adverse effects such as headache, lack of appetite, cracking of skin and enlargement of liver and spleen. “However, a deficiency of vitamin A may lead to night-blindness,” she said. According to Mr. Hau, vitamin C and E are very popular among consumers. Miss Ruby Wong, 23, of Kwun Tong, has taken vitamin C tablets regularly for two years. “I find myself healthier and more resistant to common colds,” said she. According to Ms Mimy Woo, a dietitian at the Prince of Wales Hospital, vitamin C is the most common vitamin taken by the public as it is believed that vitamin C can reduce the severity of common cold. “However,” said Ms Woo, “the actual degree of its ability to cure influenza has yet been proved. “Overdose of vitamin C is very common. The recommended daily intake of vitamin C for an adult is 30 to 40 milligrams. However, people are always taking too much of it. For example, an orange contains 60 milligrams of vitamin C while a tablet of Redoxon, a brand of vitamin C tablets, contains 1,000 milligrams.” According to Ms Woo, one’s body usually manages to get rid of excessive vitamin C through urination, except for those people who have kidney problems. She said, “Consumption of 1,000 or more milligrams of vitamin C a day may lead to vomiting, abdominal cramps, kidney stone formation and diarrhoea, depending on the allergic responses of an individual.” Miss Ho Wing Yan, 19, a year 1 student at The Chinese University of Hong Kong, started to take vitamin E tablets a year ago. She said, “People say that taking vitamin E makes our skin look healthier and more beautiful. “I’m not sure of its effects but I think it’s worth trying,” said she. According to Ms Ho of the Department of Pharmacy, large doses of vitamin E have been claimed to be useful in treating disorders such as coronary heart disease, muscular weakness and skin disorders. “However,” said Ms Ho, “current evidence is insufficient to support the above mentioned claims. “The effects of large doses of vitamin E vary from individual to individual. For some people, excessive dosage may cause fatigue, headache and blurred vision. “Reports also show that excessive vitamin E may cause prolonged blood clotting time, thus increasing chances for blood loss,” she said. In Hong Kong, most people buy vitamin supplements in drug stores. Some of them may consult doctors while others may get the information from books. Dr. Guldan said, “Actually, it is dangerous to over-reliance on vitamin tablets. “Chemical components of various fruits and vegetables are complex. Many of them are not yet identified. If we depend too much on vitamin pills, some unknown but valuable nutrients will be missed. “I strongly feel that a balanced diet should be achieved through natural food for normal and healthy people,” Dr. Guldan suggested. Ms Ho said, “Getting vitamin supplements from vitamin pills can be essential for vegetarians, patients and old people. “As we have limited knowledge about vitamins, I suggest that one should consult medical professionals such as doctors and pharmacists.”