According to the Royal Osteoporosis Society, just one 4oz (113g) serving of grilled herring will provide more than 100% of your daily recommended dose of vitamin D. That's good news for fans of Scandinavian, Nordic, Dutch, Baltic and Eastern European cuisines – these regions have elevated the pickling of herrings to a fine art, and often team the vinegary fish with rich, buttery condiments and rustic bread. While fresh herrings also deserve a try (they're delicious pan-fried or grilled), it's worth keeping an eye out for another tasty take on the fish: kippers, which, even though they're smoked, manage to hold onto most of their vitamin D.