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 scurvy.
"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 deficiency.
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.