Half a cup of sliced parsnips contains 55 calories and zero grams of fat. The same serving has 3 grams of dietary fiber and 13 grams of carbohydrates.
Parsnips are generally considered a healthy food, as they are low in fat and calories, and high in fiber, vitamins and minerals. Parsnips are relatively high in carbohydrates compared to other vegetables. These vegetables are composed of 91 percent carbohydrates, 4 percent fats and 5 percent proteins. Parsnips have an estimated glycemic load of 4, meaning they do not have a significant effect on blood sugar.
Parsnips are a good source of vitamin C, folate and manganese. A 1/2 cup serving contains 17 percent of the average daily recommended intake of vitamin C, and 11 percent of folate and manganese. Parsnips also contain 6 percent of the recommended daily intake of magnesium, 5 percent of phosphorus and pantothenic acid, and 4 percent of thiamin, vitamin E and vitamin B6.
A 1/2 cup serving of parsnips contains about four grams of sugar, making parsnips higher in sugars than similar vegetables such as carrots, radishes and turnips. The amount of sugar in parsnips is almost comparable to that of bananas. This high sugar concentration lends the vegetable its mildly sweet flavor.