If you're sick of eating spinach, other leafy greens are just as rich in vitamins and minerals. Kale and collard greens contain nutrients that benefit your immune system, muscles, bones, nerve function and overall well-being. Both are highly nutritious, but kale, which is grown in cooler climates, provides more vitamins and fewer calories than collard greens. Collards, grown primarily in the South, are higher in essential minerals.
If you are trying to lose weight or maintain your current weight, both of these vegetables are low in calories and virtually fat-free, but kale may be a little more beneficial than collard greens. A cup of cooked collard greens has 63 calories, 5 grams of protein and 7.5 grams of fiber. A cup of cooked kale has 36 calories, 2.5 grams of protein and 2.5 grams of fiber. Each has less than 2 grams of natural sugar.
Vitamins C and K
A cup of cooked kale or collard greens is a rich source of vitamins C and K, but kale is higher in both. Kale has 70 percent of your recommended daily intake for vitamin C, while collard greens provide 50 percent. Getting an adequate amount of vitamin C supports your immune system and prevents premature aging. Kale gives you 12 times the amount of vitamin K you need daily, and collard greens have 8 times your daily requirement of vitamin K. This nutrient is instrumental in blood clotting and helps prevent bleeding disorders.
Vitamins A and B-6
Leafy greens are reliable sources of vitamin A, an antioxidant nutrient that helps you see in the dark. Kale provides 885 micrograms of vitamin A per cup, while collard greens have 722 micrograms. Either gives you more than 100 percent of the 700 micrograms the Institute of Medicine recommends you get daily. Collard greens provide 17 percent of your daily requirement for vitamin B-6, making them a richer source of this nutrient than kale, which contains 13 percent of your recommended daily intake. Vitamin B-6 helps your body convert food into energy.
Although kale wins the vitamin contest, collard greens have more minerals than kale. A cup of cooked collards contains 27 percent of your recommended daily intake for calcium, while kale provides 10 percent. Collard greens also give you one-eighth of the iron and magnesium you need daily. Kale provides about 7 percent of your daily requirement for each of those minerals. If you are trying to increase your iron intake, the vitamin C in collard greens will help you absorb iron, so collard greens may be more beneficial.
Maia Appleby is a NASM-certified personal trainer with more than 15 years of experience in the fitness industry. Her articles have been published in a wide variety of print magazines and online publications, including the Gale Encyclopedia of Nursing and Allied Health, New Moon Network and Bodybuilding.com.