what vitamins if blood loss
Test Overview. A vitamin B12 test measures the amount of vitamin B12 in the blood. The body needs this B vitamin to make blood cells and to maintain a healthy nervous system. Vitamin B12 is found in animal products such as meat, shellfish, milk, cheese, and eggs.Most people who eat animal products are not likely to develop vitamin B12 deficiency anemia unless their bodies can't absorb it from food. vitamin B12 test measures the amount of vitamin B12 in the blood.