Written by Patrick B. Massey, M.D., Ph.D. A recent study suggests that a chronic cough may be associated with a vitamin B12 deficiency.
Is it possible that a B vitamin can reduce or cure a chronic cough? According to one medical study, the answer is yes.
A chronic cough is very frustrating, both for the patient as well as the physician trying to treat it. There are many reasons for a chronic cough, but some people simply cough for seemingly no good reason.
Coughing is actually a good thing. It helps to expel particles and secretions from the lungs. This, in turn, prevents infection. However, too much of a good thing is a problem. A chronic cough is commonly defined as a cough that lasts for more than eight weeks. Most chronic coughs are not serious but are annoying. They affect sleep, can make you tired and sometimes lead to muscle strain.
The most common causes of chronic cough include smoking, undiagnosed asthma, acid reflux and post nasal drip. More serious conditions that can present as a chronic cough are undiagnosed infection, lung cancer, chronic bronchitis, eosinophilic bronchitis and medication use. Some people who have a chronic cough do not have any of the above medical conditions. They are often told that there is no obvious cause and the solution is to try several medications, like dextromethorphan or codeine, to reduce the cough reflex. Sometimes they suffer for years.
There is no real data revealing how many people have a chronic cough each year, but I suspect that the number, especially in the winter, is pretty high. For those who have a chronic cough and no serious medical conditions, a vitamin B12 deficiency may be the answer.
In a recent clinical trial done through the departments of Clinical Pathophysiology and Biomedical Science and Human Oncology at the University of Turin in Italy, supplementation with vitamin B12 reduced or eliminated chronic cough in some patients.
Vitamin B12 is the largest of the B vitamins and has crucial roles in the functioning of the brain and nerves and the production of red blood cells. Deficiency is usually associated with anemia, but a change in nerve function is also a symptom. Chronic cough may be related to a dysfunctioning of the sensory nerves.
In this study, 42 patients with chronic cough were tested for B12 deficiency. Fifteen patients were vitamin B12 deficient and 27 had normal levels of vitamin B12. The vitamin B12 deficient patients had more sensitive airways to irritation, thinner skin on the throat mouth and a higher number of unhealthy nerve fibers in the throat. This combination could promote a chronic cough.
Over two months, both groups received regular, intra-muscular injections of vitamin B12 and those who were vitamin B12 deficient had significant improvements in their measurable cough thresholds including frequency. Unfortunately, those not vitamin B12 deficient did not benefit from the additional vitamin B12.
Several questions remain about this study. Would an oral B vitamin have the same results? What was the underlying cause of the vitamin B12 deficiencies? Regardless, a chronic cough has a reason and, to paraphrase a popular TV show in the 1990s, the answers are out there.
Posted February 7, 2011.