Red onion is mostly popular because of phytochemicals, which are important because they boost our immune system. Red onion is also a rich source of vitamin K, B6, and C, but at the same time, the phytochemicals act as a stimulant to vitamin C within the body. Fiber from red onion helps in functioning of the digestive tract, and it helps prevent constipation. Red onion is rich in minerals, too: it has folate, thiamine, calcium, magnesium, potassium, and manganese.
Red onion also called Spanish onion or purple onion, is a vegetable, one sort of the onion. It has red, almost purple skin and white meat with red strings. It is considered that it is the most widely cultivated species of the genus Allium. Red onion is very mild and has a sweet taste.