New Zealanders are swallowing up to $145 million in nutritional supplements every year for little or no benefit, says the author of a new report. The study in the New Zealand Medical Journal calls for regulations on the sale and manufacture of supplements. One of the authors, Murray Thomson, a senior lecturer at the Otago School of Dentistry, said yesterday that the study confirmed that "as a nation we are knocking back, swallowing, millions of dollars worth of these things." But research was needed into how well supplements, including multivitamins, minerals, herbal remedies, garlic preparations and sports formulations, worked. "A lot of stuff being sold and marketed out there is basically, as far as we can tell, probably giving people very expensive urine but maybe not much else."

The researchers studied the habits of 978 26-year-olds who are part of a group of people born in Dunedin taking part in a long-term behaviour study. They found that the use of supplements was reasonably common but also said a "surprisingly high" number had used them in the previous two weeks.

Twenty per cent of women and 13 per cent of men used nutritional supplements. One in six had taken them in the previous two weeks. Most research around the world has concentrated on the habits of older people, although a 1997 New Zealand nutritional survey reported that over 60 per cent of 19 to 24-year-olds had taken vitamin or mineral supplements. In the latest research, women consumed more iron, calcium and folate supplements. Of the small number of pregnant females in the group, 35 per cent were taking folate, important to foetal development and women's health and known to prevent spina bifida in newborn babies. Of all the supplements, men exceeded women in the use of only one category - sports formulations.

The study says herbal remedies and other plant extracts were relatively widely used, probably due to "popular perceptions" that they worked as alternatives to conventional medical therapy, including for depression. Mr Thomson said there was a potential for supplements to be used misguidedly, although no one in the study group was "overdoing" things. Using Australian figures on the use of supplements, the study estimated that New Zealanders could be spending $145 million a year on all alternative medicines or $84 million on pharmaceutical preparations. "In spite of the large scale of the industry in this country, there is a paucity of information about the use of nutrient supplements." It says more research needs to be done on how well supplements work.

Most supplements are not covered by the Medicines Act, which sets out regulations for labelling and testing. The executive director of the National Nutritional Food Association, Ron Law, said the study offered no basis for introducing regulations. "There is no evidence at all in the study to validate any discussion on regulation ... There is no evidence there that products are not what they say they are. There is no evidence there that the products are toxic. "There are about 1500 deaths in New Zealand every year from properly used medical drugs, compared to zero deaths from dietary supplements. I would ask the question: Why the excitement?"