Turnips are a cruciferous vegetable, known for their high concentrations of vitamins, minerals and health-promoting carotenoids. They're also great sources of fiber, folate and vitamins C, E and K.
Fennel, which resembles a cross between a white onion and celery, is a good source of vitamin C, potassium, fiber and folate.
You can find Brussels sprouts year-round, but their peak season is fall to mid-winter, which means they'll cost less in these colder months. They're an especially good source of vitamin C, fiber and antioxidants.
Kale and other leafy greens, like Swiss chard and collard greens, are packed with antioxidants. They're also a nice alternative to dairy for calcium and are a good source of iron and folate.
Some varieties of citrus are actually better in the winter, because they're at peak ripeness. Navel oranges, mandarin oranges and grapefruit are some of the most flavorful options.
Pomegranate is in season from late fall to early winter and is a great source of antioxidants and phytonutrients like beta-carotene, plus potassium and vitamin C.