Also known as wolfberry, goji is a red-orange berry most commonly found in China.
Miracle Nutrient: Carotenoids. Some makers of goji products claim this berry can work miracles like extending one's life. There's no proof of that, but goji is particularly rich in the carotenoid beta-carotene, which the body turns into retinol, a form of vitamin A that may boost the immune system.
Mega Price: An 18-ounce bag of dried goji berries can cost $20; a liter bottle of goji juice typically costs $35.
Common Sources: Plain old leafy greens are an excellent source of beta-carotene. A half-cup serving of boiled spinach provides 230 percent of your daily value (DV); the same amount of kale offers 190 percent DV. Carrots are another source (one raw carrot provides 175 percent DV), as are apricots, peas, and red peppers.