B group of vitamins, mainly B6, B9 and B12 are the most important for brain functions. These vitamins allow for the conversion of food to energy, build neurotransmitters and maintain covering nerves, or myelin. B Vitamins are found in rich foods: leafy greens, whole grain cereals, eggs, milk, and fortified cereals. The absence of these vitamins leads to fatigue, mood swings, and a deterioration in intellectual function. It is especially essential to take supplements for B12 in vegetarians and the elderly due to difficulty in absorption or dietary limitation.
