no multi
vitamin is better over and above mother's milk, multi vitamin are just supplements to it.
however vitd3 is less in mother's milk so it is wise to give it for abt a year.additional dha are not mandatory for brain development as mothers milk contain adequate dha and ada required for development of nervous system which not only brain but all of nervous system development occurs. stimulate baby to surrounding and also bondage between mother and baby, and other family members will make him more interactive and thus give task to his brain and will inturn make him active to the surrounding which will help him develop.
Next Steps
just play and interact a lot with the baby tat is the most important stimulus for overall development
Health Tips
do visit a pediatrician for knowing abt various interaction technique