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Strict vegetarians should consider increasing the amount of dark-colored
vegetables in their diets in order to avoid deficiencies
in vitamin A and iron,
according to an Institute of Medicine report that adjusts recommended
levels of vitamin A and several other nutrients.
The Institute of Medicine (IOM) panel issuing the report announced
that vegetables such as carrots, broccoli and sweet
potatoes, usually relied upon to provide vitamin A, only deliver
to the body half the amount of usable nutrient as previously
thought. Vitamin A deficiency is not usually a concern in developed
countries because the vitamin is abundant in dairy products, fish
and liver.
But people who avoid animal products altogether should be careful
to get enough dark fruits and vegetables high in carotenoids,
the metabolic precursors to vitamin A, to guarantee optimal
vision and lower the risk of birth defects, according
to Dr. Robert Russell, who chaired the IOM panel on micronutrients.
"This doesn't mean fruit and vegetable consumption must double,"
said Russell, a professor of medicine and nutrition at Tufts University
in Boston, Massachusetts.
The panel adjusted slightly the overall recommended dietary allowance
(RDA) of vitamin A set in 1989. New recommended levels are
900 micrograms per day for men
and 700 micrograms per day for women.
Twelve micrograms of beta-carotene equals 1 microgram of vitamin
A in the body.
"The RDA for this nutrient can be met by choosing foods rich
in provitamin A and vitamin A without taking supplements,"
Russell said. "A half-cup of cooked carrots will give
the full RDA."
The panel also changed slightly its recommendations for daily
iron intake to 8 milligrams (mg) per day for
men and postmenopausal women
and 18 mg per day for premenopausal
women. Many pregnant women do not get all of the 27 mg
of iron per day recommended to prevent iron deficiency anemia, and
some of these women may need iron supplements, the report indicates.
Vegetarians may have to double their daily intake
of iron over the recommended numbers since the body absorbs iron
found in cereals, bread, and vegetables less efficiently than it
does iron found in meats.
The panel did not have enough scientific data to set RDAs for vitamin
K, though it did report that daily consumption of spinach, cabbage
or broccoli would provide men
the 120 micrograms per day and women
the 90 micrograms per day deemed adequate.
Institute of Medicine (IOM),
Washington Jan 09 2001
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