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Excessive and Prolonged Intake of Vitamins Could Bring Harm to Health – 80% of Samples beyond Regulatory Oversight of Pharmacy Ordinance

  • 2018.09.18

The lack of regular meals and exercise has driven many city inhabitants to health products especially vitamin supplements in the belief that besides convenience, a vitamin or two a day will effectively meet their body needs and keep them healthy.  A thriving market in response to such health demand has boomed with products for different age and gender groups targeting children, pregnant women and the elderly.  But a Consumer Council survey on 76 samples of multi or single vitamin supplements has shown the suggested dose of 9 samples to be in excess or equivalent to the daily tolerable upper intake level of the Chinese Nutrition Society, and vastly above the recommended intake level. Excessive intake of vitamins over a prolonged period has no health benefits but that it may lead to adverse side-effects preventing normal function of the body.  A more severe risk is fat soluble vitamins A, D, E and K which can accumulate in thebody over the long term.   The fact is a balanced diet is the proper way of acquiring sufficient nutrients for the body.  Should one have any special need for vitamin intake, they should first consult medical practitioner to avoid adverse impact on health.

The Council is also highly concerned over the grey areas in the regulatory oversight of health foods in Hong Kong.  Among the samples surveyed only 16 were Hong Kong registered pharmaceutical products under the Pharmacy and Poisons Ordinance.  The remainders nearly 80% (60 samples) which are likely being classified as general food products and thus regulated under the Public Health and Municipal Services Ordinance.  Consumers are reminded that health food products differ from other foodstuffs, prolonged intake of excessive amount could cause potentially serious harm to body.  The authorities are urged to look into the problem and strengthen regulatory oversight of the ingredients and dosage, adopt such other measures like regular random sample inspection, and ensuring matching claims and labels on nutrition, to safeguard consumer health.

Included in the 76 vitamin supplement samples were: 27 multivitamins, 11 vitamin B, 16 vitamin C, 17 vitamin D and 5 vitamin E.  19 of the vitamins were specified for use of children, 4 multivitamins for women in pregnancy or intending to conceive.  Prices varied widely; a vitamin for adults could cost from $1 to $7.3. Based on the highest suggested daily use of the samples, the costs varied from $1 to $18.3, the annual total costs would run up to as much as $6,600.  Should one be taking several vitamin supplements a day, the annual total costs would mount even higher. 

With reference to the daily tolerable upper intake level (UL) laid down by the Chinese Nutrition Society’s Chinese dietary reference intakes, consumption exceeding that upper limit will increase the chances of serious side-effect.  Based on the labelled nutrition ingredient level and recommended intake, 9 samples’ recommended intake was found to be in excess or equivalent to the tolerable UL. Among them, 5 samples and 4 samples were in excess or equivalent to the tolerable UL for adults and children respectively.

Among those samples’ recommended intake equivalent to the tolerable UL was 1 sample, specified for pregnant women, of a multi vitamin with folic acid content reaching 1,000mcg per day, which is the tolerable UL for adults.  The suggested B6 dosage for adult of 2 Vitamin B samples also exceeded the tolerable UL; one of them had folic acid level up to 1,000mcg.  Pregnant women with sufficient folic acid intake could lower the risk of the fetus developing neural tube defect but the intake should not exceed 1,000mcg per day as research showed that pregnant women with insufficient or excessive intake of folic acid both could increase the chances of neural tube defect or autism disorder to the fetus.  Long term excessive intake of vitamin B6 can cause nerve diseases and skin problem such as extreme sensitivity to sunlight. 

Further, the suggested dosage of 2 vitamin C samples was up to 2,000mg, equivalent to the tolerable UL for adults.  Another 1 sample’s suggested dose for children of 8 years or above was 1,000mg per day, equivalent to the tolerable UL (1,000mg) under the standard.  Though water soluble vitamin C would not accumulate in the body, excessive of them could still cause osmotic effect in intestines inducing diarrhea, nausea, abdominal cramps, and possibly kidney stones.

1 vitamin E suggested dosage for aged 4 and above was 1 tablet per day but content of each tablet was in excess of the tolerable UL for a 4 year child.  Excessive intake of vitamin E could reduce blood coagulation ability and in rare cases, it could increasing the risk of abnormal bleeding or even haemorrhagic stroke in some serious cases.  People suffering blood clotting problems or taking anticoagulant drugs should be wary.  Clinical research has pointed to the risk of prostate cancer by middle aged men taking excessive vitamin E, though the finding is inconclusive and subject to further research.

In fact, the body need for vitamins is much less and far below the tolerable UL.  The daily tolerable UL set out under the Chinese dietary reference for vitamin C is 2,000mg, whereas the recommended intake is only 100mg per day, an immense difference of 20 time.  A medium-size kiwi fruit or orange contains about 63mg of vitamin C.  If one follows the principle of 2 servings of fruit every day, one could actually intake more than 100mg of vitamin C a day by eating one kiwi fruit and an orange.

For folic acid, the recommended intake is 400mcg per day, but daily tolerable UL is 1,000mcg.  Besides, the daily tolerable UL for vitamin D is 50mcg but in fact it recommends only 10mcg will suffice.  Among the 12 vitamin D samples that stated dose for adults, 8 contained more than 10mcg vitamin D, 3 with just 10mcg, and 1 lower than 10mcg (8.25mcg).  Vitamins consumed in excess of the normal body needs may not confer additional health benefit.  On the contrary, excessive intake of vitamin as fat soluble vitamin D will accumulate in the body and that may lead to health problem in the long term.

Some of the vitamin samples look very much alike candies though they should not exceed the tolerable upper intake level if taken in accordance with the product suggested dose.  Nevertheless parents should be cautious not to allow children to have free access to vitamin supplements that are candies look-alike to avoid excessive consumption harmful to health.

The Council stressed the importance of consumers developing healthy life style – maintaining balanced diet, regular work and rest –  is far superior and effective than relying on vitamin supplements to keep precious health.

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