25 Aug 2011
By: GRACE MA
SALES engineer Scott Chong takes one effervescent tablet containing 1,000mg of vitamin C daily.
“I feel that I am not able to get the vitamins I need from my daily meals. When I take it every day, I feel more refreshed and less tired,” says Mr Chong, 28.
What Mr Chong may not know is that his daily intake of vitamin C of 1,000mg far exceeds the recommended dietary allowance (RDA) of 30mg for a Singaporean adult.
What is RDA?
The RDA of any vitamin or mineral refers to the recommended daily levels of nutrients required to meet the needs of nearly all healthy individuals in a particular age and gender group. The amount will vary depending on one’s age and gender, and if the person is pregnant or breastfeeding.
According to Ms Nehal Kamdar, senior dietitian at Raffles Internal Medicine Centre, a healthy individual consuming a well-balanced diet that follows good cooking practices does not require additional multivitamins.
“However, poor food choices coupled with a stressful lifestyle means that a general multivitamin may be recommended,” she says.
Special conditions such as pregnancy, iron deficiency, anemia or osteoporosis may also warrant a need for a specific vitamin or a general multivitamin.
Ms Pindar Yu, principal dietitian of Singapore General Hospital’s Dietetics & Nutrition Services department, explains that there is no single food that provides all the vitamins and minerals needed for good health.
For example, the 30mg RDA of vitamin C can be achieved simply by having two servings of vegetables and fruits, which translate to any of the following: a 250ml glass of pure fruit juice; one small fruit like apple, orange or pear; or a wedge of pineapple or watermelon.
General multivitamins may provide some nutritional coverage against missing specific nutrients due to special dietary restrictions or increased requirement from the body, says Ms Yu.
More is not better
Most multivitamin supplements contain the daily RDA for vitamins and minerals. There are also RDAs for children and adolescents, but children should meet theirs by having a variety of food, most of which, like milk and breakfast cereals, are already fortified with vitamins and minerals.
Parents wanting to boost their children’s immunity need to be aware that more is not always better and can even be dangerous.
They should consult qualified health-care professionals first and avoid giving big doses to their children as some vitamins can become toxic if taken in large quantities, warns Ms Yu.
According to a Health Sciences Authority (HSA) spokesman, health supplements are currently not subjected to approval, licensing or registration before being sold in the local market, neither are they assessed by HSA for their effectiveness, unlike medicines.
What HSA does is to conduct risk-based market surveillance by sampling and testing products found in the market as well as obtain feedback from consumers, the media and the industry.
It also has an adverse reaction monitoring programme where it draws on its local and international networks of health-care professionals and national regulatory partners to pick up signs of any products that may be causing reactions.
Health supplement dealers, who include manufacturers, importers, wholesalers, retailers, are responsible for ensuring that their health products do not contain prohibited ingredients and that the level of toxic heavy metals found in these products are within the safety limits set by HSA.
Make an informed choice
The onus therefore is on the consumer to make an informed decision.
Ms Yu recommends that consumers check product labels and consume only the dosage recommended on the product.
It is also safer to purchase them from a licensed pharmacy or through a doctor’s prescription as the quality and safety of products sold over the Internet could be unknown.
Buyers should consult a doctor if they are taking any medications to ensure that the vitamins do not have any potentially dangerous reaction with the medicines, even if the label says that they contain natural or organic ingredients.
Advertisement claims that sound too good to be true, usually are.
Under HSA regulations, health supplement dealers generally do not need to apply for a permit before they advertise their products. However, they must ensure that their products do not make claims to treat illnesses or diseases.
Information on the product packaging must also be printed clearly and contain sufficient details to enable consumers to make an informed purchase decision.
Ms Yu says: “There is not enough evidence to support that supplements can prevent or treat any diseases. Unlike medicinal drugs which are tested under a strict criterion of clinical trials, multi-vitamins are not tested with the same process.”
In Mr Chong’s case, although his daily intake of vitamin C is way above the RDA of 30mg, it is still within the tolerable upper intake level (UL), which refers to the highest amount of daily nutrient intake that does not show adverse health effects to most individuals in the general population, says Ms Yu.
For vitamin C, its UL for adults is 2,000mg per day, according to the United States Department of Agriculture, Food and Nutrition Information Centre.
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