Here are the nutrition facts for celery, according to the U.S. Food and Drug Administration(opens in new tab) (FDA):

Serving size: 2 medium stalks (110 grams/3.9 oz) 

Calories: 15 (Calories from fat 0)

Amount per serving (and %DV*) *Percent Daily Values (%DV) are based on a 2,000 calorie diet.

Total fat: 0 grams (0%)

Total carbohydrate: 4 grams (1%) 

Dietary fiber: 2 grams (8%) 

Sugars: 2 grams

Sodium: 115 milligrams (5%) 

Potassium: 260 milligrams (7%)

Protein: 0 grams

Vitamin A: (10%) 

Vitamin C: (15%) 

Calcium: (4%) 

Iron: (2%) 

Unlike some vegetables, celery retains most of its nutrients even if it is steamed. A study published in 2011 in the journal LWT – Food and Science Technology(opens in new tab) compared celery that had been steamed, boiled and blanched and found that, after 10 minutes of steaming, the vegetable still maintained 83% to 99% of its antioxidants, compared with uncooked celery. On the other hand, boiling and blanching led to a 38% to 41% loss in antioxidants.