A chronic cough can be a symptom of allergies, asthma, reflux or a side effect of certain kinds of blood pressure medication. Italian scientists now suggest that an unexplained cough may also be a result of a vitamin B12 deficiency. The researchers studied 42 people with unexplained chronic cough. They were tested for vitamin B12 deficiency and for reaction to inhaled histamine. This compound triggered coughing, especially among those patients with vitamin B12 deficiency.
Treatment with vitamin B12 injections over two months resulted in a significant improvement. The authors hypothesize that vitamin B12 deficiency affects nerve growth factors and makes upper airways super sensitive. Because vitamin B12 deficiency can occur as a result of long-term use of popular acid-suppressing drugs, people with chronic cough should request a workup for this nutrient.
