Table 3.

Examples of antioxidant concentration in fruits, vegetables and in supplement preparations available on the market

Dietary antioxidants	Rich dietary sources	Concentration in foods (mg/100 g)	Concentration in supplements*** (mg/capsule)
Vitamin C	bell pepper, citrus fruits140,141	10–170	100–1000
Quercetin	apples, onions140	4–46	100–800
Carotenoids	leafy vegetables, plums, tomatoes, watermelon, carrots140,141	0.2–10	5–15
EGCG	green tea142	5–450#	25–360
Selenium*	fish (dairy producs, potato, rice)140,141	1–150*	0.07–0.20
Vitamin E	fish, meat, leafy vegetables140,141	0.2–10	400 IU**
Isoflavonoids	soy, beans, peanuts140,143	0.1–155	50–150

*µg/100 g

^#mg/cup (ca. 225 mL of tea beverage)

^**1 IU alpha tocopherol = 0.667 mg

^***internet data.