Vitamin D deficiency has become a very popular topic in lay and professional literature, and deservedly so.  Vitamin D is important not only for bone health, but for normal functioning of many organs.  Its deficiency appears to be much more common than it was previously suspected.  Dr. Steve Wheeler has found vitamin D deficiency in 42% of 55 patients with chronic migraine headaches.  He presented these findings at the recent meeting of the American Headache Society.  We do not have evidence that taking vitamin D will help relieve headaches, however if a deficiency is present correcting it can certainly improve overall health of the patient.  One possible cause of what appears to be increasing incidence of vitamin D deficiency is widespread use of prescription and over-the-counter antacids.  Reducing stomach acidity helps relieve heartburn and other symptoms of reflux, but it may also interfere with absorption of vitamins and minerals.