Peppers are a nutrient-rich spice like calcium, vitamins A and C, and there is some evidence that peppers can reduce the risk of cardiovascular disease, help prevent diabetes and boost metabolism. They may also have some ability to limit the progression of cancer cells.

Nutritional qualities of chilli:
Cayenne peppers have surprisingly high levels of vitamins and minerals and contain an impressive list of health-promoting chemicals. Just 100 g provides (as a% of the recommended daily allowance):
240% vitamin C (ascorbic acid),
39% of vitamin B-6 (Pyridoxine),
32% vitamin A,
13% iron,
14% copper,
7% potassium,
Especially no cholesterol.

Fresh red and green peppers are rich in vitamin C. 100 g provides about 143.7 μg or about 240% of RDA. Vitamin C is a powerful water-soluble antioxidant. It is necessary for the synthesis of collagen inside the human body. Collagen is one of the main structural proteins needed to maintain the integrity of blood vessels, skin, organs and bones.

Regular consumption of foods rich in vitamin C helps protect against scurvy, build resistance against infectious agents (boosts immunity), and removes harmful pro-inflammatory free radicals from the body.
They also have a high content of vitamin A, and flavonoids like ß-carotene, a-carotene, lutein, zea-xanthine and cryptoxanthin. These antioxidant substances and especially the capsicum which protects the body against the harmful effects of free radicals generated during stress and diseases.
Peppers carry a good amount of minerals like potassium, manganese, iron and magnesium. Potassium is an important component of cell and body fluids that helps control heart rate and blood pressure. Manganese is used by the body as a co-factor for the antioxidant enzyme, superoxide dismutase.