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--> June 19, 2000 -- Reaching the new RDA (recommended dietary allowance) for vitamin C is easy if you incorporate a variety of fruits and vegetables into your diet, says Felicia Busch, MPH, a registered dietitian in St. Paul, Minn. A diet that contains five servings of fruits and vegetables should put you at about 200 milligrams a day.
According to the new Institute of Medicine recommendations, men need 90 milligrams of vitamin C a day, while women need 75 milligrams. If you're pregnant, try for 80 to 85 milligrams, and if you're nursing, you'll need 115 to 120 milligrams. Smokers also need about 35 milligrams more because they deplete their stores of vitamin C faster.
Citrus fruits, berries, and peppers are particularly rich sources of vitamin C, Busch says. Some specific food values are listed below. Busch doesn't recommend vitamin C supplements as an alternative or complement to fruits and vegetables. "A bad diet with supplements is still a bad diet, and you should really focus on eating a diet of nutritious foods first," she says.
Another thing to remember is that vitamin levels begin to diminish after food is harvested. The longer produce has been in storage or in transit, the less vitamin C it will contain. So choose fresh fruits and vegetables whenever possible. And if it comes down to a choice between out-of-season fresh produce and frozen, take frozen. Out-of-season produce often travels long distances to reach market and therefore loses more of its nutritional value.
How you prepare food is also important. To preserve as much of the vitamin content as possible, either steam the food or microwave it with as little water as possible, Bush says. Boiling is the worst thing you can do. It causes the greatest loss of vitamin content because the food remains at high temperatures for a long period of time, which either destroys the vitamins or allows them to escape into the water.
Here's the vitamin C content of some common foods, provided by Mark Levine, MD, an endocrinologist at the National Institutes of Health:
Source (in milligrams) Amount of Vitamin C 1/2 cup orange juice 50 1/2 cup fortified grape juice 120 medium orange 70 medium kiwi fruit 75 1 cup sliced strawberries 95 1/4 medium cantaloupe 60 1/2 cup cooked broccoli 60 1/2 cup cooked Brussels sprouts 50 50 medium baked potato 25 1/2 cup raw tomato 15 baked sweet potato 30 1/2 cup fresh, cooked snow peas 40 40 1/2 cup raw green pepper 65
Mitchell Leslie is a freelance science writer who lives in Belmont, Calif.