Asparagus is an excellent source of vitamin K; B vitamins, including folate, thiamine, riboflavin, niacin, and B6; and vitamins A and C. It is a good source of the minerals iron, potassium, manganese, copper, and phosphorus. Asparagus provides plenty of fiber and, for a vegetable, a substantial amount of protein.
Asparagus contains asparagine, a non-essential amino acid that contributes to its protein content. It also contains asparagusic acid, which is unique to asparagus.
One effect of asparagusic acid is that it causes an unusual smell in the urine of people who have eaten the vegetable. It is known in some folk medicine traditions for its diuretic properties, when this effect may be even more apparent! It has also been used for rheumatism and arthritis, and its effectiveness there suggests anti-inflammatory properties.Nutritional Facts
Six spears of cooked asparagus provide 22 calories, 3.8 g carbohydrate, 2.3 g protein, 0.3 g fat, 1.4 g dietary fiber, 485 IU vitamin A, 10 mg vitamin C, 1 mg niacin, 131 mcg folic acid, 144 mg potassium, 10 mg sodium, 49 mg phosphorus, 18 mg calcium, and 9 mg magnesium.