Nutrition watchdogs are warning expensive vitamin supplements
are unlikely to boost vitality or immunity - despite
widespread belief they are the key to good health.
Nutrition Foundation spokeswoman Sarah Hanrahan says it is
"silly" for people to continue to believe the hype on vitamin
supplements, particularly vitamin C.
Hanrahan, a registered dietician, says she is puzzled such
products continue to be marketed as the answer to health and
well-being, despite scientific evidence that disproves its
"It's not like an energy drink. You don't need a vitamin C
hit," she says. "For all the talk around it, you'd be better
off having a piece of fruit."
Hanrahan points out the doses found in vitamin C products are
sometimes more than 20 times the recommended daily intake set
by the Ministry of Health. The recommended doses are 40mg for
children, 45mg for adults and 60mg for pregnant women.
Vitamin C products are often sold as 250mg tablets (100 for
around $10), 500mg tablets (100 for around $25) and 1000mg
tablets (100 for around $25).
An orange has about 30mg and half a cup of broccoli has 110mg
of vitamin C, and the latest government research indicates
most New Zealanders are getting more than double the
recommended daily intake through their diets, she says.
Although the supplements industry argues high doses of
vitamin C are beneficial, Hanrahan says the science-based
nutrition community is unconvinced.
"It's going to flush straight through your body. It's not
stored, so you can't stock up on vitamin C now so that you
have enough for next week."
Professor Shaun Holt, a medical researcher who focuses on
natural health, says there are proven beneficial products on
the market, such as fish oil and echinacea, but many are
marketed with "shonky research and old wives' tales".
Vitamin C falls into the latter category, he says.
"The evidence is weak. You'd be better off spending your
money on echinacea and zinc, which have been shown to reduce
the duration of a cold by around half a day."
However, Natural Products NZ executive director Michelle
Palmer, who represents most of the supplements industry,
points to research showing a daily supplement with 1000mg to
3000mg of vitamin C helps maintain good health and that
6000mg daily can cut down the duration of a cold.
Holt says it is important to look at the entire body of
research on a subject, rather than isolated studies. The
Cochrane Collaboration, an independent, worldwide network of
researchers, had reviewed all published literature on the
subject and concluded it was proven to help only
"You can get a study to show just about anything, which is
why studies need to be repeated and tested. You have to look
at the totality of what research is showing," Holt says.
- Celeste Gorrell Anstiss of the Herald on Sunday