Sunshine Vitamin Cuts Cancer Risk
Having a higher level of vitamin D in your blood means you are less
like to develop bowel cancer than those with low levels, according
A study published in the British Medical Journal has concluded
that those with the highest levels of the vitamin were at 40 per
cent lower risk of developing the disease compared with those
with the lowest levels.
Scientists looked at vitamin D quantities in 1,248 people with
bowel cancer and 1,248 controls in the largest ever study of the
The research was carried out by scientists at the International
Agency for Research on Cancer (IARC) in Lyon, France, and Imperial
College London, and was funded by World Cancer Research Fund (WCRF).
It comes after medical experts expressed concern yesterday about
the rising number of cases of rickets - caused by vitamin D deficiency
- and called for it to be added to milk and other food products.
The main source of vitamin D is sunlight, through skin exposure,
but it is also present in a small number of foods, such as oily
fish or cod liver oil.
According to the research team, although the latest study provides
evidence of a link between vitamin D and bowel cancer it does
not prove that taking vitamin D supplements prevents the disease.
More studies are needed to find out the potential impact on other
cancers and the effects of taking extra vitamin D doses, scientists
Dr Panagiota Mitrou, science programme manager for WCRF, said:
'This is the biggest ever study on this subject and there is now
quite a lot of evidence from studying populations that people
who have low levels of vitamin D are more likely to develop bowel
'The next step is to carry out new clinical trials to try to
confirm whether vitamin D supplementation can reduce the risk
of bowel cancer and whether there are any harmful effects of higher
levels of vitamin D.
'Looking at the figures in this latest study, it suggests that
increasing the UK's vitamin D intake by ten per cent could prevent
seven per cent of cases.
'And when you think that there are about 37,500 cases diagnosed
in the UK every year, that could have a big impact.
'But we need to emphasise that, for the moment, the findings
need to be treated with caution and they are certainly not enough
evidence to suggest that we should be taking supplements to increase
levels of vitamin D.
'The best advice for reducing risk of bowel cancer remains to
stop smoking, maintain a healthy weight, be regularly physically
active, to eat more fibre and less red and processed meats and
to cut down on alcohol.'
Dr Mazda Jenab, the lead author of the study from the International
Agency for Research on Cancer, said: 'Our results support a role
for vitamin D in the etiology of colorectal cancer, but this has
to be balanced with caution regarding the potential toxic effects
of too much vitamin D and the fact that very little is known about
the association of vitamin D with either increased or reduced
risk of other cancers.'
January 26, 2010