Vitamin K deficiency is associated with malnutrition in some complications, such as hyperemesis gravidarum, active gastrointestinal diseases, and psychological disorders. Maternal vitamin K deficiency can cause fetal bleeding, in particular, fetal intracranial hemorrhage. Although fetal hemorrhage is uncommon, severe damage to the fetus may be inevitable. We describe a pregnant woman with vitamin K deficiency possibly due to hyperemesis gravidarum. The patient was treated for the deficiency, and no fetal or neonatal hemorrhagic diseases were manifested.