New RDA For Vitamin C Suggested For Healthy Young Women


August 14, 2001WESTPORT (Reuters Health) - The recommended daily allowance
(RDA) of vitamin C for young healthy women should be increased from 75 mg per
day to 90 mg per day, the same as the RDA for men, according to a report in
the Proceedings of the National Academy of Sciences for August 14.
"In April of 2000 new dietary allowances for vitamin C were released by the
Food and Nutrition Board of the National Academy of Sciences," Dr. Mark
Levine from the National Institutes of Health, Bethesda, Maryland, noted in
an interview with Reuters Health. "The data available were only for men, and
the Food and Nutrition Board estimated women's RDA by using differences
between men and women's body weight," he added.
The RDAs for vitamin C from the Food and Nutrition Board were 90 mg daily for
men and 75 mg daily for women.
"The Food and Nutrition Board set very clear criteria as to how they
calculated an RDA for men and we used the same criteria to calculate an RDA
for women, and it came out to 90 mg of vitamin C per day, the same as for
men," Dr. Levine said. In an inpatient depletion-repletion study, he and
colleagues gave a wide range of vitamin C doses (30 mg to 2500 mg daily) to
15 healthy women 19 to 27 years of age.
Dr. Levine does not believe that the RDA of vitamin C should be derived from
vitamin supplements. "Ninety milligrams of vitamin C can be easily achieved
by eating five servings a day of a variety of fresh fruits and vegetables,"
he stressed. "We do not know if the benefits of vitamin C are from vitamin C
alone, or in combination with other things in fruits and vegetables," he
added.
There are no data on the RDA of vitamin C for older women, diabetics and
smokers, Dr. Levine said. "Recommendations need to be made for public health
even if we do not have complete data," he said. "While this study adds more
information about vitamin C, it is not the complete story--more work needs to
be done."
Proc Natl Acad Sci 2001;98:9842-9846.