From: tgray@igc.apc.org (Tom Gray)
Newsgroups: sci.med
Subject: Folic Acid & Birth Defects
Date: 4 Oct 92 21:05:00 GMT
Nf-ID: #N:cdp:1467700007:000:5553
Nf-From: cdp.UUCP!tgray    Oct  4 14:05:00 1992


From: Tom Gray <tgray>
Subject: Folic Acid & Birth Defects

/* Written 12:03 am  Sep 24, 1992 by newsdesk in cdp:ips.englibrary */
/* ---------- "WOMEN: Vitamins prevent birth defec" ---------- */
Copyright Inter Press Service 1992, all rights reserved.  Permission to re-
print within 7 days of original date only with permission from 'newsdesk'.

Area: Trade & Finance
Title: WOMEN: Vitamins prevent birth defects


an inter press service feature

by judith perera

london, sep 21 (ips) -- vitamins taken by pregnant women can help
to prevent certain serious birth defects, according to the results
of a recently released international study.

neural tube defects (ntd) like hydrocephalus and spina bifida --
birth defects in which the spinal column does not form properly --
can cause severe physical and mental disability in those children
who survive. but the simple precaution of taking folic acid -- one
of the b victims -- during pregnancy can cut down the incidence by
two-thirds.

''the results of our study offer a chance to prevent one of the
most serious causes of physical handicaps in children,'' says
study coordinator nicholas wald, professor of preventative
environmental medicine at st. bartholomew's hospital in london.

the study also looked at the effects of other vitamins but folic
acid was clearly the most effective. it is a water-based soluble b
vitamin which occurs naturally in green vegetables, meat and fish.

although ntds like spina bifida are more common in europe than
asia or africa, there are regions in the third world where rates
are high. one region just north of beijing in china, for instance,
has a very high incidence and sikh communities are also at risk
even after emigration from india.

in europe, the united kingdom has one of the highest rates at an
average of 1.1 per 1,000 births and northern ireland has one of
the highest rates in the world at 3.4 per 1,000. among third world
countries, mexico has a high rate at 1.4 while in africa and
especially the west indies, the rate is very low.

north india shows a high incidence at 2.3, according to a study
done in the late 1970s by dr. ishwar verma at the paediatrics
department of the jawaharlal institute of postgraduate medical
education and research in pondicherry.

and in north india he found a large variation between regions
with the highest rates in sikh areas. the rate for chandigarh, for
instance, was 3.9. studies of immigrant communities in britain and
canada confirm a continuing high rate of ntds among sikhs.

british studies have also shown a high incidence of various birth
defects including ndts among pakistani immigrants.

the causes of ntd are still not understood and most experts
believe there are many different factors involved, including
genetic and environmental elements.(more/ips)

women: vitamins prevent birth defects(2-e)

women: vitamins (2)

but there is now a growing body of evidence to suggest that,
whatever the causes, folic acid supplements taken during the first
six weeks of pregnancy can dramatically reduce the incidence.

the link between spina bifida and vitamins was first investigated
in the late 1970s by professor richard smithells at leeds
university. he looked at the levels of different vitamins in the
blood of almost 1,000 pregnant women and found that in six who
subsequently had babies with spina bifida levels of folic acid and
vitamin c were significantly lower.

smithells, now retired, says he began the investigation because
there was already some evidence suggesting folic acid deficiency
could be a contributory factor in ntds like spina bifida.

''the condition was much more common among the lower social
classes, suggesting a possible role for nutrition,'' he said. in
addition, an anti-cancer drug being used at the time called
aminopterin, which was a folic acid antagonist, was also known to
cause birth defects in man and had been shown experimentally to
cause ntds in animals.

the next step was to see whether giving vitamin supplements to
pregnant women would reduce the incidence of ntds and smithells,
in the early 1980s, organised a large trial to test this.

this involved giving vitamin supplements including folic acid to
around 500 women at special risk -- women who had already produced
one child with ntd were known to have a five percent chance of
producing another compared with 1.1 per 1,000 live births for the
population in general.

when these were compared with a control group of women at risk
smithells found that ntd recurrence rates among those given
vitamins were only 0.7 percent compared with 4.6 percent for those
in the control group at risk.

several other smaller studies in britain and a major study in the
united states produced similar results and these have now been
confirmed by the international investigation.

the precise way folic acid works is not known, but according to
dr. israel chanarin, an expert on folic acid metabolism, it is
necessary for the formation of three out of four acids which are
the building blocks of dna -- the genetic material of all cells.

without it, cells cannot multiply or grow. it remains a puzzle,
however, why it should affect the formation of neural tube in the
embryo rather than any other organ.

but whatever the mechanism, there is enough evidence to suggest
that the incidence of this deformity may be dramatically reduced
by simply giving folic acid supplements to pregnant women and
especially those known to be at special risk because of their
history, community or region.(end/ips/cw/jp/cdm/92)
Newsgroups: sci.med