Myopathy refers to a muscular disease in which muscle fibers do not function, resulting in muscular weakness and wasting. Vitamin D deficiency is a well-recognized cause of myopathy, and excessive drinking is often associated with low or subnormal levels of vitamin D. A review of studies of the relationship between alcohol-related myopathy and vitamin D deficiency indicates that vitamin D deficiency might partly explain the occurrence of the frequently observed myopathy in chronic alcoholism.
Results will be published in a special online issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.
â€œMyopathy simply means â€˜muscle disease,â€™â€ said Jan W. Wijnia, a researcher at Slingedael Korsakoff Center as well as corresponding author for the study. â€œMuscle weakness is by far the most frequent symptom of alcoholic myopathy, causing difficulties in rising from a chair or in climbing a staircase. In alcoholic myopathy, improvement of muscle weakness usually occurs six to nine months following alcohol abstinence.â€
â€œIt seems that 40 to 60 percent of alcoholics suffer from alcohol-related myopathy,â€ said Frits A. J. Muskiet, a professor of pathophysiology and clinical chemical analysis at the University Medical Center Groningen. â€œMany subjects with chronic alcoholism have low vitamin D, which prompted the authors to raise the question whether the well-known muscle weakness might be caused by vitamin D deficiency. The answer is that indeed the symptoms of myopathy in alcoholism and vitamin D deficiency are very similar, but since these symptoms are rather aspecific, this is no more than an association, which is obviously not the same as a proven cause-and-effect relation. There are similarities, but also differences.â€
Study authors reviewed articles on alcoholic myopathy and hypovitaminosis D myopathy (n=93) that were listed on PubMed from January 1985 through to September 2011. They analyzed and compared the pathophysiological findings in order to designate or â€œchartâ€ possible pathways of vitamin D action in the development of alcohol-related myopathy.
â€œOur review links possible interdependent deficiencies of vitamin D, phosphate, and magnesium with muscle weakness in chronic alcoholism,â€ said Wijnia. â€œPrevious studies had suggested that changes in alcoholic muscle disease were not due to dietary deficiencies, but our review is one of the few to examine the effects of severe vitamin D deficiency in alcoholic myopathy.â€
Muskiet agreed. â€œThey have reviewed the literature to show to us that vitamin D deficiency might â€“ at least in part â€“ explain the occurrence of the frequently observed myopathy in chronic alcoholism,â€ he said. â€œThe paper is important because of this connection, but the real proof of the pudding should now be provided by doing research trials.â€
â€œThe causes of vitamin D deficiencies in alcoholics may include liver dysfunction, lack of sun exposure, malabsorption, and inadequate dietary intake,â€ added Wijnia.