Eggs, fish, seafood, grass fed beef and liver and the absolute best foods to eat for a smart baby.u003cbr/u003eA few nutrients directly affect baby's brain development - (in no particular order) Vitamin B12, omega 3, idoine, iron, folate, DHA and choline. Of these nutrients, DHA, omega 3, iodine and choline stand out. Adequate DHA intake is associated with higher IQ levels among children. Great sources of DHA are fatty fishes and seafood, eggs and grass fed beef. But DHA needs omega 3 to maximize its function and cross the placenta. To get good doses of omega 3, eat grass fed beef, eggs, fish and seafood, or a quality fish oil supplement. Iodine supports brain development, and inadequate intake of iodine is the leading cause of preventable intellectual disability worldwide. Fish, seafood and dairy products are the best sources of iodine. Lastly, choline is linked to normal brain development and enhanced memory. By far, the best sources of choline are eggs and liver.