Serving size of 1cup (28g) Cereals, fortified (ready to eat) has 1.500mcg-6.220mcg vitamin B12, which is 53-222% of the daily vitamin RDA for lactating women.
Cereals, fortified (ready to eat) can also be a good source for other priority 1 nutrients for lactating women such as Vitamin B6, “true” vitamin A (retinol), Vitamin B1, Vitamin B2, and vitamin E.
The vitamin content in each specific cereal can vary largely, so pay attention to the manufacture food label for details.
Find a recipe with cereals here