5 Must-Haves You Are Missing from Your Diet
You need: 2.4 mcg (2.6 mcg if you're pregnant, 2.8 mcg if you're nursing).
You get: If you're a vegan or vegetarian, or you go for days without meat, fish or eggs, it's likely you're not getting enough vitamin B12. Adults over 50 also tend to have a harder time absorbing this vitamin, says Willett (a problem, especially since a deficiency accelerates cognitive decline, as do those with some intestinal and gastric conditions.
Good sources: Pescatarians, you're in luck: Clams are off the charts in B12, and rainbow trout and salmon are pretty high, too. If you don't eat any animal products at all, look for fortified cereals, nutritional yeast and supplements with 100 percent of the recommended daily value.