Is Low-Carb Eating Increasing Scurvy?
Eating Low-Carb? Don't Forget Potatoes, Other Foods Rich in Vitamin C
June 10, 2004 -- The ancient mariners had scurvy. And
apparently, plenty of Americans today have it, too. We're not getting enough
vitamin C, the main preventative for scurvy or vitamin C deficiency,
researchers say. Could low-carb eating be to blame?
The report appears in the current issue of the American
Journal of Public Health.
It provides results from a large nationwide survey, showing
that seniors and children get the most vitamin C in their diet. However, men
and women aged 25 to 44 get the least -- and are most at risk for developing
"A considerable number of U.S. residents are vitamin C
deficient," writes researcher Carol Johnston, a professor of nutrition at
Arizona State University.
Other studies have shown similar results, she writes. One U.S.
study shows that 18% of adults get fewer than 30 milligrams daily of vitamin C.
Another study shows that up to 20% of the 13- to 18-year-old group gets fewer
than 30 milligrams daily.
Because scurvy is rarely suspected, people with the symptoms --
fatigue, limping, bleeding gums, or swollen extremities -- may not be tested
for vitamin C deficiency, she explains. Very often, these patients are
misdiagnosed and medicated for other disorders -- not for their vitamin
The recommended daily allowance for vitamin C is 75 milligrams
for women and 90 milligrams for men. While some people get too much vitamin C
in their diets, many others get too little, she says. The body excretes excess
vitamin C in the urine.
With the low-carb craze, the vitamin C-rich potato -- once the
centerpiece of a healthy diet -- has been pushed aside, notes Althea Zanecosky,
MS, RD, a spokeswoman for the American Dietetic Association and professor of
sports and nutrition at Drexel University in Philadelphia. She agreed to
comment on Johnston's study.
"Potatoes are a great source of vitamin C and other
nutrients," Zanecosky tells WebMD. Other vitamin C-rich fruits are also
taboo for some people adopting a low-carb diet.
The Study Details
In her study, Johnston used data from health and diet surveys
completed by 15,769 Americans aged 12 to 74. Each person surveyed also had his
or her blood tested for vitamin C levels.
Among her findings:
- 14% of males and 10% of females were vitamin C deficient.
- Only 6% of 12- to 17-year-olds were deficient.
- The adults aged 25 to 44 had the worst vitamin C levels.
Nearly one-quarter -- 23% -- of males aged 25 to 44 were
vitamin C deficient, compared with 15% of 65- to 74-year-olds.
Among females, 20% of those aged 25 to 44 were deficient,
whereas 13% of 65- to 74-year-olds were also vitamin C deficient.
- Smokers were nearly four times as likely to be vitamin C deficient as
- Those who didn't take a vitamin supplement were three times as likely to be
deficient in vitamin C.