Just 3 oz. of sardines are enough for your daily dose of vitamin D. They are the best substitute for the much more expensive superfood – salmon, Maria Bohland, a registered dietician and founder of DietAustin.com, says. Add tomato sauce for some fiber and vitamins. This easy meal contains 427 IU or 107 percent of your DV (daily value) of vitamin D. Sardines are rich on omega-3 fatty acids, which reduce the risk of stroke. If you’re worried about mercury in your fish, sardines are known to have low levels of it.