DEAR DOCTOR K: I was recently diagnosed with a vitamin B12 deficiency. Can I take B12 supplements by mouth? Or do I need the shots?
DEAR READER: Tissues throughout the body need vitamin B12, especially in the brain, spinal cord and bone marrow, where blood cells are made. Vitamin B12 in the diet gets absorbed in the part of the small intestine called the ileum. There, it enters the blood. Vitamin B12 deficiency can cause anemia, and problems with the bones, brain and spinal cord. Low vitamin B12 levels in the blood basically have two causes: Either there is not enough B12 in the diet, or the B12 in the diet has trouble getting absorbed by the ileum. B12 is found naturally only in animal products like meat, fish, poultry, eggs and milk. Many cereals are fortified with it.