Dietary supplements are regulated in New Zealand by the 1985 Dietary Supplements Regulations, which fall under the 1981 Food Act.
But back in 1985, supplements most commonly came in tablet, capsule or powder form.
Over the last two decades a new category of products described by the New Zealand Food Safety Authority as "food-type dietary supplements" or " complementary foods", which fall outside of the scope of the regulations.
According to the agency, the outdated regulation means that such products fall into a black hole between supplements and regular foods, and could have safety implications for consumers.
Such products (bars, beverages or a host of other formats) are known in other markets as functional or fortified foods.
The NZFSA has published a discussion paper setting out proposed changes, and is accepting comments until the end of this month.
"Unlike ordinary foods regulated under the [Australia New Zealand Food Standards] Code, complementary foods involve little or no safety assessments," said Carole Inkster, director of food standards at NZFSA.
"This can lead to problems such as the lack of warning labels or appropriate advice on the safe use of products, where there may be reasons against certain populations using them (those on some medications, for example)", she added.
NZFSA is proposing that food-type supplements be regulated under a new set of regulations.
As for therapeutic-type supplements - defined as those that offer medicinal or healing benefits, including vitamins, minerals, herbal and traditional remedies - Inkster said "It's proposed that [they will] continue to be regulated under amended Dietary Supplements Regulations administered by MedSafe, pending a move to regulation as complementary medicines under proposed new therapeutic product legislation."
The agency also stressed that foods containing intoxicating substances (in such quantities as to intoxicate) would not be eligible for regulation as dietary supplements.
At present, such products may be sold as supplements with little or no safety assessment, if they are naturally derived from foods.
"Society has a general expectation that risks associated with the use of intoxicating substances require regulation, for example the control of alcohol under the Sale of Liquor Act and the standards under the Code relating to alcoholic drinks," said the agency in its discussion paper.
This is not the first time in recent years that the issue of supplement regulation has raised its head in New Zealand.
An earlier discussion document was released by the NZFSA in 2004 proposing changes.
However one year earlier New Zealand and Australia had signed an agreement to establish a joint scheme for regulating therapeutic products.
Although NZFSA says that there was general support for the changes, they were delayed pending the establishment of the Australia New Zealand Therapeutic Products Authority (ANZTPA).
ANZTPA's joint regulatory scheme for complementary medicines is currently also at the proposal stage.
Based on categories or scales of risk, it is intended to regulate the safety, quality and effectiveness of therapeutic products including their manufacture, supply, import, export and promotion in both Australia and New Zealand.
New Zealand is not the only country to be taking a look at food-type supplement products.
In December, the United States' FDA heard views on whether it should tailor regulations for the functional food and drink category, which has grown in importance and is regarded by some as occupying a grey area between conventional foods and dietary supplements.