DEAR DOCTOR K: I had some blood work done recently and was surprised to learn that I am deficient in vitamin D. How is this possible? What can I do about it?
DEAR READER: Vitamin D is an unusual vitamin. We get most vitamins from the foods we eat; our body can't make them. Unfortunately, vitamin D isn't found naturally in many foods. Fatty fish and milk (which is fortified with vitamin D) are the main food sources.