There is a trend of taking supplements in Hong Kong in recent years. It is said that supplements have various functions. Therefore, people may often take different kinds of supplements at the same time without paying attention to the ingredients and intake limits. Overdose will be caused easily because different supplements may contain the same nutrients. There is a daily intake limit for different nutrients. Greater intakes may result in over-accumulation of such kind of nutrients in human body, which may lead to discomfort and even poisoning.

Vitamin C is one of the most popular supplements providing functions of strengthening immune system, whitening skin and reducing dark spots. The daily intake for an adult is 45mg according to the recommendation of the World Health Organization. In general, supplements available in the market contain 25mg to 1,500mg of vitamin C. If the daily intake amount of vitamin C exceeds 1,000mg, only 30% of it will be absorbed and the remaining will be excreted. Moreover, overdose of vitamin C may cause diarrhea and a higher chance of suffering from kidney stones.

Fish oil pills and cod liver oil are also popular supplements providing functions of protecting the heart and blood vessels, lowering cholesterol and relieving arthritis pain. Some people think that both supplements are nearly the same as both have omega-3 fatty acids. However, cod liver oil actually contains abundant vitamin A and D as well, which are oil soluble nutrients. Over-accumulation of vitamin A and D in body fat may cause symptoms liked stomachache, diarrhea, vomiting and blurred vision. Pregnant women with too much vitamin A will bring harmful effect to the fetus and can increase the risk of miscarriage.

Overdose of supplements may run counter to your desire. In fact, adequate vitamin C can be taken by frequent intake of natural food, such as kiwi, capsicum, strawberry, orange and papaya, while enough omega-3 fatty acids can be absorbed from salmon, mackerel, tuna and flaxseed. As long as we maintain a diverse and balanced diet, nutrients required daily can be obtained.

Harriet Chan
Registered Dietitian
MSL Nutritional Diet Centre