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Genetic Link To Vitamin A Deficiency
Reported November 17, 2009
Almost half of UK women may be lacking an important source of vitamin A due
to a previously undiscovered genetic variation, scientists at Newcastle
University have found.
The team, led by Dr Georg Lietz, has shown that almost 50 per cent of women
have a genetic variation which reduces their ability to produce sufficient
amounts of vitamin A from beta-carotene.
Vitamin A – also known as retinol – plays a vital role in strengthening our
immune system, protecting us against common infections such as flu and
winter vomiting. Vitamin A also helps to maintain healthy skin and mucus
linings such as inside the nose and the lungs.
In 1987, an American study found that excessive use of vitamin A during
pregnancy was associated with certain birth defects. Beta-carotene, however,
was deemed to be safe and this led to the general advice that we should eat
more of this nutrient, allowing the body to convert what it needs into
vitamin A.
However, Dr Lietz’ latest research – published in the FASEB Journal and
presented this month at the 2nd Hohenheim Nutrition Conference in Stuttgart
– shows that for many women, beta-carotene is not an effective substitute
for vitamin A.
Dr Lietz explained: "Vitamin A is incredibly important – particularly at
this time of year when we are all trying to fight off the winter colds and
flu.
"It boosts our immune system and reduces the risk of inflammation such as
that associated with chest infections.
"What our research shows is that many women are simply not getting enough of
this vital nutrient because their bodies are not able to convert the
beta-carotene."
From a volunteer group of 62 women, the team found that 29 of them – 47 per
cent – carried the genetic variation which prevented them from being able to
effectively convert beta-carotene into vitamin A.
The study also showed that all volunteers consumed only about a third of
their recommended intake from 'preformed’ vitamin A – the form found in
products such as eggs and milk – indicating that those volunteers carrying
the genetic variation were not eating enough vitamin A-rich foods to reach
the optimum level their body required to function.
"Worryingly, younger women are at particular risk," explained Dr Lietz, who
is based in the School of Agriculture, Food and Rural Development at
Newcastle University.
"The older generations tend to eat more eggs, milk and liver which are
naturally rich in vitamin A whereas the health-conscious youngsters on
low-fat diets are relying heavily on the beta-carotene form of the
nutrient."
The next step in the study is to assess whether the effect of the genetic
variation can also be observed in men and whether our body composition will
influence our ability to absorb and convert beta-carotene into vitamin A.
The team is now looking to recruit volunteers to take part in the next stage
of the study. They are looking for healthy, non-smoking men and women aged
between 18 and 45 to take part in the study which lasts two weeks.
Source: Newcastle University |
