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.
Richest among all the vitamin B complex foods are milk, yeast, liver, whole-grain cereals, nuts, eggs, yogurt, fruits, meats and leafy vegetables. Vitamin B1 is an essential vitamin that aids in conversion of carbohydrates into energy.