Nutritional Facts For One Serving Of Lettuce

Lettuce has been cultivated for its nutritional value for millennia, and today remains a staple of just about any serious diet menu. Not all lettuce is equally nutritious, and the iceberg lettuce that makes up the bulk of this vegetable eaten by Americans is one of the least nutritious choices available. All species of lettuce are ideally consumed raw, not only to ensure you get the most nutrients, but also because cooked lettuce is rarely satisfying. Exceptions can include utilizing braised or steamed lettuce leaves in soup.

Serving Size

A serving size is about 3.5 ounces, but can depend on lettuce variety. A serving size based on a cup of shredded lettuce can vary from 2.5 grams for iceberg lettuce down to a gram for red leaf lettuce. Focusing on weight provides a more efficient manner for comparing the nutrients found in the various species of the vegetable.

Red Leaf Lettuce

Red leaf lettuce is more appropriate for boiling than some of the green leaf varieties, according to the University of Illinois. A 3.5-ounce serving of red leaf lettuce contains just 16 calories that are composed of a number of important vitamins and minerals. The 7,493 IU of vitamin A in this serving provides 150 percent of the recommended daily value. Also abundant in red leaf lettuce is vitamin K, where the 140 mcg amounts to 175 percent of the daily value. Daily values in excess of 2 percent of many minerals can be enjoyed in red leaf lettuce. Adding this vegetable to your diet will bring 33 mg of calcium, 187 mg of potassium, 25 mg of sodium, and the 0.2 mg of manganese provides a tenth of your daily requirement.

Butterhead Lettuce

Butterhead lettuce is a collective name given to the Boston and Bibb varieties. Adding butterhead lettuce to your diet several times a week can boost the efficiency of your immune system, courtesy of the 3.7 mg of vitamin C and 73 mcg of folate. The 13 calories supplied by 3.5 ounces of butterhead lettuce include 102 mcg of vitamin K, which more than meets your recommended daily value. The 1.2 mg of iron and 238 mg of potassium put 7 percent of your daily value of these minerals into your bloodstream.

Romaine Lettuce

“Prevention" magazine’s "Nutrition Adviser” feature refers to romaine as the king of the lettuces due to its high concentration of nutrients. Within the 17 calories packed into 3.5 ounces of romaine lettuce are 174 percent of the recommended daily value of Vitamin A and 128 percent of the recommended daily amount of vitamin K. Vitamin C and folate are also heavily represented in romaine, with 24 mg and 136 mcg respectively. A steady diet of romaine lettuce can help keep your blood pressure down due to the 14 mg of magnesium and 247 mg of potassium working together to regulate heart rhythm.

Iceberg Lettuce

The iceberg variety of lettuce might offer a low 14 calories per 3.5-ounce serving, but that’s where a single serving stops being competitive with other types. Iceberg lettuce does not feature a single vitamin that provides even close to the recommended daily values. The 24.1 mcg of vitamin E gives you just 30 percent of the daily value, or DV, and the 502 IU of vitamin A only gets you a tenth of your DV. Iceberg lettuce also falls well behind the other varieties in its 18 mg of calcium, 7 mg of magnesium and 141 mg of potassium.