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.
The best sources of Vitamin B 12 include: eggs, milk, cheese, milk products, meat, fish, shellfish and poultry. Some soy and rice beverages as well as soy based meat substitutes are fortified with vitamin B12. To see if a product contains vitamin B 12 check the Nutrition Facts on the food label. You need vitamin B 12 to form DNA, make healthy blood cells and keep nerves working properly. 2  Low levels of vitamin B 12 can cause pernicious anemia. 3  Vegetarians who eat no animal products and the elderly who absorb less vitamin B 12 are most at risk. 4  Vitamin B12 is found only in animal foods and fortified foods.