Your baby resembles a tadpole more than a human, but is growing fast. The circulatory system is beginning to form, and the tiny heart will start to beat this week. Your baby is the size of a sesame seed. Read about your pregnancy at 5 weeks.
Stores of B12 can last for up to a year. Foods high in Vitamin B12 include shellfish, liver, fish, crab, fortified soy products (tofu, soymilk), fortified cereals, red meat, low fat dairy, cheese, and eggs.
Though vitamin B12 can be taken as a dietary supplement, the best source of the vitamin is found in many common foods. Here are a few of the foods you should try to eat if you are deficient in vitamin B12: 1. Eggs. The raw yellow portion of a chicken egg contains large amounts of vitamin B12.