Red and yellow grapefruit, often called white grapefruit, are closely related varieties of the same citrus fruit, Citrus paradisi. It's a hybrid cross between a variety of pomelo and a variety of sweet orange that was originally developed in Barbados. Most grapefruit sold in the U.S. is grown in Florida, although Texas and California are also major producers. Grapefruit produces a large fruit with a tangy and slightly bitter flavor.
The biggest difference between white and red grapefruits is in vitamin A content. Red grapefruit has significantly higher levels of this nutrient. One cup of red grapefruit provides about 2,645 international units or 50 percent of your daily recommended intake of vitamin A. In contrast, white grapefruit only offers 2 percent of your daily recommended amount.
Vitamin C and Potassium
Although red and white grapefruits differ markedly in the amounts of some nutrients, in other cases they are essentially equivalent. All grapefruit varieties are high in vitamin C, and there is very little difference between red and white grapefruit in regards to this nutrient. One cup of grapefruit provides about 70 mg or 120 percent of your daily vitamin C needs. Red and white grapefruits also contain about the same amount of potassium. One cup contains about 300 mg or 15 percent of your recommended daily intake.
Sugar, Fiber and Calories
The sugar, fiber and total calorie values of red and white grapefruits are roughly comparable One cup of red grapefruit contains about 97 calories, 16 g of sugar and 4 g or 15 percent of your daily recommended intake of fiber. One cup of white grapefruit has 76 calories, 17 g of sugar and 3 g or 10 percent of your daily recommended intake of fiber.
Red grapefruit is noticeably sweeter than white grapefruit, despite the fact that they have comparable sugar content. Red grapefruit is therefore preferred by many consumers and is now both more widely sold and easier to find than the older white grapefruit varieties.
Grapefruit and Medications
A certain enzyme found in grapefruit juice can interact with certain prescription medications, greatly and sometimes dangerously enhancing their effects. Drugs used to treat high blood pressure and thyroid conditions are among those affected. Check with your doctor if you're on any prescription medications before consuming grapefruit regularly.