We thank Dr Daniel Ng Peng Keat for his feedback ("HSA should review stance on health supplements"; Aug 24).
Health supplements generally contain low-risk ingredients, such as vitamins, minerals and substances derived from natural sources, and are not intended to diagnose, treat, cure or prevent any diseases.
In Singapore, health supplements are, therefore, not subjected to pre-market approvals and licensing for their manufacture, importation and sales, unlike medicine which contains potent medicinal ingredients.
Nonetheless, the Health Sciences Authority (HSA) requires dealers to ensure the safety and quality of their health supplements before they are marketed.
This includes ensuring that they do not contain any other active substances except those stated on the label or any prohibited ingredients, such as steroids and other potent ingredients used in prescription-only medicine.
The levels of toxic heavy metals and microbials found in these products should also be within safety limits set by HSA.
For products in the market, HSA has a risk-based post-market surveillance programme to sample and test these products for any harmful contaminants and adulterants.
HSA also relies on its adverse reaction monitoring programme to pick up early signals of any products that may be causing harm to patients, as well as alerts issued by overseas regulatory agencies.
Targeted surveillance and investigations will be conducted, and products found to be unsafe will be withdrawn from the market.
Manuka honey, an example raised by Dr Ng, is regulated by the Agri-Food and Veterinary Authority (AVA) as a food product.
Methylglyoxal is a chemical naturally formed in manuka honey during storage over time. A healthy person has natural defence mechanisms to remove methylglyoxal from the body.
There have been various studies with contradictory results on the link of methylglyoxal and several age-related problems such as diabetes.
The scientific community is of the view that more research is needed before findings on the health effects of methylglyoxal is conclusive.
Like any food product, manuka honey products are required to meet Singapore's food safety standards and labelling requirements.
In addition, all food products must not carry claims of medicinal and therapeutic properties.
Individuals with medical conditions should consult their medical professionals on appropriate dietary choices.
Raymond Chua (Assistant Professor)
Health Products Regulation Group
Health Sciences Authority
Astrid Yeo (Dr)
Regulatory Administration Group
Agri-Food and Veterinary Authority