Does this sound familiar: a client sneezes on his hand, wipes it on his pants then sticks it out to be shaken. Meanwhile, he’s already touched three doors on the way to your office, sneezed over your desk, made a call on your phone and handed you a business card, coated with germs.It’s flu season, how are you going to arm yourself flu shot or one of those over the counter remedies claiming to be a preventive?In addition to getting a flu shot, you can also strengthen your immune system by building up your vitamin D levels. People with higher amounts of vitamin D in their system are less likely to catch colds and viruses, and are even less likely to have a heart attack than people with very low levels of vitamin D.In the old days mothers would get vitamin D into their children by sitting on them and forcing foul tasting cod liver oil down their throats. Cod liver oil has one of the highest levels of vitamin D compared to any other food, but it doesn’t taste very good.A yummier alternative might be the food with the second highest level of vitamin D, salmon. Salmon is a superfood that is also thought to contain chemicals that provide special support for joint cartilage, insulin effectiveness, and control of inflammation in the digestive tract.Wild salmon reportedly has more vitamin D than farmed salmon. However, there have been some concerns about high levels of mercury in salmon. The Monterey Bay Seafood Watch guide recommends as a best choice: sockeye, king, pink, and chum salmon from Alaska, among others types of salmon. A good alternative might be similar species from California, Oregon or Washington. It recommends avoiding farmed salmon from anywhere. (See the full list at www.montereybayaquarium.org) .Many other types of seafood also have large amounts of vitamin D including mackerel, tuna and sardines, and oysters. Mushrooms, particularly dried shiitake mushrooms, are also a good source of the vitamin.So here is a delicious flu fighting recipe. May the vitamin D force be with you.Flu fighting salmon recipe.Ingredients3tbs olive oil3 shallots, finely chopped½lb fresh sliced shiitake mushrooms or portobellos2oz of dried shiitake mushrooms (for an extra vitamin D kick).¼ cup of half and half1tsp chopped fresh thymesalt and pepper.10oz box of frozen spinach or 1 ½ cups of fresh spinach leaves, lightly packed4 6oz salmon fillets. (Some experts believe wild salmon pack more vitamin D punch).2tbs fresh lemon juiceMethodFollow the directions on the dried mushroom package to reconstitute. Heat two tablespoons of oil in a pan over medium-high heat. Add the shallots and cook for two minutes, stirring often, until golden brown. Add reconstituted dried and fresh mushrooms and cook, stirring occasionally, until softened, three to four minutes. Stir in the cream, thyme, salt, and a dash of pepper. Reduce the heat to medium and cook, stirring often, until thickened, about two minutes. Remove the pan from the heat and stir in the spinach until wilted. Transfer to a bowl and cover with foil to keep warm. Clean the pan and return it to the stove.Heat the remaining oil in the pan over medium heat. Sprinkle one teaspoon of salt and pepper to taste over salmon. Arrange the salmon in the pan skin side up in a single layer and cook, turning once, until golden brown and just cooked through, around eight minutes. Plate the salmon.Mix the lemon juice with one tablespoon of water, add to the pan, and cook, scraping up any browned bits, until just thickened, about half a minute. Drizzle the pan juices over the salmon and serve with the warm shiitake mixture.