With its broad, dark green, flat leaves, collard greens might be an unusual juicing ingredient, but they are chock-full of nutritional value. The U.S. Department of Agriculture suggests that women consume at least 1.5 cups of dark green leafy vegetables per week, with the amount rising to 2 cups for adult men. A 2-ounce serving of collard green juice contains a little more than 1.75 cups of fresh collards, helping you meet -- or nearly meet -- that weekly amount.

You might not think it at first, but collard greens are a rich source of calcium. As the mineral found in greatest quantity throughout your body, calcium helps build strong bones and teeth. It is also needed for cellular communication and regulating your body’s hormone levels, as well as helping with blood clotting. A 2-ounce serving of fresh collard juice contains 147 milligrams of calcium per serving. This is almost 15 percent of the recommended dietary allowance for adults.

Vitamin K is also known as the clotting vitamin, as it is essential for your body to produce blood clots. Insufficient amounts of vitamin K can lead to abnormal bruising or bleeding and difficulty recovering from wounds. It also helps your body with calcium absorption and use, so it helps your body maintain strong bones and teeth. A 2-ounce serving of collard greens juice contains almost 277 micrograms of vitamin K. This is over 100 percent of the recommended adequate intake for men and women.

Folate is a water-soluble vitamin, meaning excess amounts will be expelled by your body, so regular intake of this essential B vitamin is necessary. Folate helps with cell and tissue growth and function. It can also help prevent anemia, as well as certain birth defects. A 2-ounce serving of fresh collard juice contains 82 micrograms of folate. This is a little over 20 percent of the acceptable intake for men and women and 16.4 percent of what's acceptable for pregnant and breast-feeding women.

Collard greens are a low-calorie, low-fat source of nutrition, with a 2-ounce serving of the green containing only 20 calories. The same size serving also has less than 0.5 gram of total fat -- the majority of which is polyunsaturated fat -- and almost 2 grams of protein. The sugar content of collard green juice is also minimal, with approximately 0.3 grams of sugar per 2-ounce serving.