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.
These vitamins help the process your body uses to get or make energy from the food you eat. They also help form red blood cells. You can get B vitamins from proteins such as fish, poultry, meat, eggs, and dairy products. Leafy green vegetables, beans, and peas also have B vitamins.