Body & Brain
400
IU daily
New vitamin
D target for
infants
600
IU daily
New vitamin D
target for ages
1 to 70
800
IU daily
New vitamin D
target for people
over 70
Panel increases
vitamin D targets
But some scientists say new
numbers are still way too low
By Nathan Seppa
A scientific panel has called for tripling
the recommended dietary allowance of
vitamin D for most children and adults
and raising the amount slightly for older
people. The panel also doubled the upper
level of vitamin D that older children
and adults can safely take in any given
day from 2,000 international units to
4,000. The panel’s report, commissioned
by the National Academies’ Institute of
Medicine at the request of the U.S. and
Canadian governments, was released
November 30.
Vitamin D recommendations hadn’t
been changed since 1997. Despite a wave
of studies suggesting that the nutrient has
benefits far beyond bone health, the panel
restricted its rationale to just that. Apart
from aiding bone fitness, the panel said,
the benefits of vitamin D “are currently
not supported by evidence that could be
judged either convincing or adequate.”
“We had to look at the totality of the
evidence,” says Patsy Brannon, a molec-
ular nutritionist at Cornell University
who served on the panel. The
panel scoured studies show-
ing vitamin D’s effects on
other health problems but
found “very limited random-
ized control trials,” she says.
The panel
says fears
of vitamin D
deficiency
might be
overblown.
H1N1 exploited antibody mismatch
Middle-aged flu victims may have succumbed to friendly fire
By Tina Hesman Saey
Faulty immunological memories could
have made middle-aged people more
susceptible to the 2009 H1N1 pandemic
flu, a new study shows.
Middle-aged people’s bodies tried to
defend against H1N1 by hurling antibodies for similar viruses at the new flu.
But the old antibodies’ aim wasn’t true
and may have ended up backfiring, a
study published online December 5 in
Nature Medicine suggests.
In most flu seasons, the most vulnera-
ble people are infants and the elderly. But
during the 2009 H1N1 pandemic, young
adults and middle-aged people were hit
unusually hard, says viral immunologist
Fernando Polack of Vanderbilt University
in Nashville, a coauthor of the study.
