From foodconsumer.org
When It Comes to Vitamins, More Is Not Always Better
By Rosalie Marion Bliss
Nov 16, 2007 - 6:00:06 PM
Researchers
funded by the Agricultural Research Service (ARS) looked into links
between dietary intakes of two B vitamins--folate and vitamin B12--and
mental agility among seniors. Folate and B12 are important nutrients
for the development of healthy nerves and blood cells. ARS is the U.S.
Department of Agriculture's chief scientific research agency.
The
study, published in 2007, was led by epidemiologist Martha Morris and
colleagues at the ARS Jean Mayer USDA Human Nutrition Research Center
on Aging (HNRCA) in Boston, Mass. It was based on an analysis of data
collected from the U.S. population for the National Health and
Nutrition Examination Survey between 1999 and 2002. Blood tests were
used to determine the volunteers' folate and vitamin B12 levels.
U.S.-enriched
cereal grain products have been fortified with the synthetic form of
folate (folic acid) since 1998. The HNRCA's Paul Jacques and Jacob
Selhub, coauthors on the 2007 study, had previously published papers
with Silvina Choumenkovitch, reporting that folate levels have become
extremely high in the U.S. population since fortification began.
The
researchers found an interesting association among seniors aged 60 and
older whose vitamin B12 blood levels were low. Aging and taking
stomach-acid blockers can contribute to a gradual lessening of B12
absorption in the body.
People with high folate and low B12
status were found to be at a disadvantage when compared to those with
normal folate and low B12 status; the former group was more likely to
exhibit both anemia and cognitive impairment, according to Jacques. A
single cognitive function test was used to assess aptitudes such as
response speed, sustained attention, visual-spatial skills, associative
learning and memory.
Scientists have long known that being
seriously deficient in vitamin B12 leads to impaired cognitive function
caused by neurological complications. The researchers recommend future
studies that look into the implications of having too much folic acid,
due to fortification, and too little vitamin B12, due to poor
absorption.
Read more about this research in the November/December 2007 issue of Agricultural Research magazine, available online at:
http://www.ars.usda.gov/is/AR
/archive/nov07/brain1107.htm
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ARS News Service
Agricultural Research Service, USDA
Rosalie Marion Bliss, (301) 504-4318, rosalie.bliss@ars.usda.gov
November 16, 2007
--View this report online, plus photos and related stories, at www.ars.usda.gov/is/pr
Originally published on ARS.USDA