Healthy Skepticism Library item: 19448

Warning: This library includes all items relevant to health product marketing that we are aware of regardless of quality. Often we do not agree with all or part of the contents.

Publication type: Journal Article

Saunders C
More proof vitamin pills do little
MJA InSight 2011 Mar 28;
http://www.mjainsight.com.au/

Abstract:

MOST people do not need multivitamins and should be warned they are
flushing away their money, say Australian experts commenting on the
latest study showing little evidence vitamin products do any good.

“Australians are probably second only to Americans in having expensive
urine,” said Professor Colin Binns, professor of public health at Curtin
University in Perth.

“I guess people want to take a pill to solve all of their ills rather
than looking after their lifestyle ― diet, exercise, etcetera.”

Professor Ric Day, professor of clinical pharmacology at the University
of New South Wales and St Vincent’s Hospital, Sydney, said toxicity had
been described with excessive dosages of registered vitamin products and
it was always important that patients not exceed recommended doses found
on the labels.

“If individuals are well, eating a balanced diet, getting adequate sun
exposure and not abusing alcohol, tobacco or other recreational drugs
then they usually do not need vitamins,” he said.

An annual check with the GP was a good screen for an individual’s health
and diagnosis of any vitamin deficiencies. Patients with chronic illness
might need vitamin supplementation.

“Being on the look out for vitamin C, B group and D deficiency in the
elderly is important,” Professor Day said. “(They are) much more prone
to deficiency.”

The latest study on multivitamin use, reported in the American Journal
of Epidemiology, found no clear decrease or increase in mortality from
all causes, cardiovascular disease, or cancer and in morbidity from
overall or major cancers among multivitamin supplement users. (1)

The findings did not vary across subgroups by ethnicity, age, body mass
index, pre-existing illness, single vitamin/mineral supplement use,
hormone replacement therapy use, and smoking status.

There was also no evidence indicating that multivitamin use was
associated with risk of cancer, overall or at major sites, such as lung,
colorectum, prostate and breast.

Professor Ian Caterson, professor of human nutrition at the University
of Sydney, said, in general, healthy adults and children in Australia
did not need vitamins and, in some cases, vitamins could do harm.

There were some situations when supplements could be given, such as
folate for pregnant women, and in cases of specific deficiency
situations, but these were rare in Australia, he said.

Professor Binns said the problem with most nutrition effects was that
there was a U-shaped curve. “If we are deficient in vitamin A then it
has severe effects (but) too much vitamin A is dangerous too,” he said.

National Health and Medical Research Council guidelines recommended
calcium for women, vitamin D for people aged over 65, folate, iodine and
usually iron for pregnancy, and iodine for breastfeeding, he said.

Professor Alastair MacLennan, of the University of Adelaide and head of
a research group in South Australia that has monitored the use of
complementary and alternative medicines (CAMs) for almost two decades,
said their surveys showed that 60% of women and 44% of men used CAMs,
with women using significantly more vitamins and other products that
were not prescribed than men.

Professor MacLennan said vitamins should be prescribed only to the very
few Australians who were shown to be vitamin deficient by validated
tests.

“The reasons for their use are mostly due to the marketing of these
products and a wish to self-medicate,” he said.

“In Australia, the public spends four times as much on CAMs as their
contribution to all registered pharmaceuticals, some of which are
subsidised,” Professor MacLennan said. (2)

The experts agreed that clever and forceful marketing was largely
responsible for the exponential increase in the use of vitamins that
were not prescribed.

In a recent article in the Brisbane Times, the founder of an American
charity that provides vitamins for children in the developing world said
they were an “essential” part of every modern diet. (3)

Vitamin Angels founder Howard Schiffer said people critical of using
vitamin supplements were “naive”.

Professor Binns said several studies supported the findings of the
latest study, including a Cochrane review in 2008 of 67 randomised
controlled trials that found no evidence to support antioxidant
supplements — beta-carotene, vitamin A, vitamin C, vitamin E, and
selenium ― to prevent mortality in healthy people or patients with
various diseases. (4)

“Antioxidant supplements need to be considered medicinal products and
should undergo sufficient evaluation before marketing,” the authors
said.

1. American Journal of Epidemiology 2011; DOI: 10.1093/aje/kwq447

2. Prev Med, 2002; 35 (2):166-173

3. Brisbane Times, 22 March 2011
4. Cochrane Database of Systematic Reviews 2008