Salads can be an important component of a healthy diet. According to Everyday Health, leafy salad greens have been linked to a number of health benefits. Greens are one of the top sources of dietary nitrates, which are compounds that promote heart health. Carefully prepared salads that focus on nutrition and don’t contain creamy dressings also can be low-calorie options that help individuals maintain a healthy weight.

When it comes to selecting salad greens, many people have their go-to items. But being mindful of the nutritional value of various types of greens can compel more people to add salad to their diets. Here’s a look at how many greens stack up.

Kale: The United States Department of Agriculture says just one cup of cooked kale meets 19 percent of a person’s daily requirement for vitamin A and 23 percent of the requirement for vitamin C. Kale also contains more than four times the daily requirement of vitamin K. Even though kale contains 31 calories per cup, the high calorie count compared to other greens is offset by its nutritional benefits.

Spinach: A serving of spinach contains twice the amount of the daily recommendation of vitamin A as well as half of the daily recommended amount of vitamin K. Spinach also contains folate, vitamin C and iron, all of which promote health in various ways and make it one of the more popular salad greens.

Swiss chard: Although less common than other salad greens, Swiss chard is another healthy green that should be included in salads. While Swiss chard has a higher sodium count than other greens, it’s only three percent of the maximum recommended daily amount. Swiss chard contains a high amount of vitamin K and potassium.

Romaine: For those looking to maximize vitamin A intake, look no further than romaine. This leafy green contains 4,904 IU of vitamin A, according to Harvard Health. Romaine has a great crunch and is good on sandwiches and in salads. It also can be lightly grilled for a unique flavor.

Beet greens: Most people purchase beets without the greens, but they are missing out on a nutritious element that can be added to salads. The beet greens contain almost 100 percent of the daily requirement of vitamin A and all one’s daily vitamin K needs. Beet greens can be enjoyed raw in salads or sauteed as a tasty side dish.

Collards: The USDA says collard greens are a good source of vitamin C that also include vitamin K and a small amount of vitamin E. Collards are a staple of southern cooking. Although they take a little longer to cook, they’re often worth the wait. They also taste great raw in salads.

When choosing traditional lettuces for salads, iceberg tends to have the least nutritional value. Iceberg lettuce is mostly water and has a low fiber content. Butter lettuces have vitamin A, some calcium and iron.