Plant foods are not enriched with Vitamin B12. Vitamin B12 is not developed from plant food sources. The main sources of Vitamin B12 are meat, fish, eggs and other poultry foods.
Milk and milk products are a good source of Vitamin B12.
Some Indian morning cereals are Vitamin B12 rich such as wheat, oats meal etc.
Margarine is a good source of Vitamin B12, but it is not recommended food as it is also a good provider of trans-fat which increases the bad cholesterol level.
Required daily amount will be vary in adults and different ages of children.
Adults: 2.5 micrograms, or mcg
9-13 years: 1.8 to 2mcg
4-8 years: 1.2 to 1.5 mcg
1-3 years: 1 to 1.2mcg
0-1 year: 0.5 mcg