Severe myopathy associated with vitamin D deficiency in western New York

Five cases of severe myopathy associated with vitamin D deficiency are desc ribed. Each patient was confined to a wheelchair because of weakness and im mobility. Two were: elderly, 1 was a 37-year-old African American with type 1 diabetes mellitus, 1 was being treated for carcinoid syndrome, and 1 was severely malnourished due to poor oral intake. In each, weakness had previ ously been attributed to other causes, including old age, concomitant diabe tic neuropathy, or general debility. Correct diagnosis was made initially b y a high index of suspicion, following the demonstration of clinical proxim al myopathy; confirmation was made by the demonstration of low 25-hydroxyvi tamin D and elevated parathyroid hormone concentrations. Treatment with vit amin D caused a resolution of body aches and pains and a restoration of nor mal muscle strength in 4 to 6 weeks. Four patients became fully mobile and had normal 25-hydroxyvitamin D concentrations, and the fifth also became mo bile. In the 4 fully recovered cases, parathyroid hormone levels on follow- up were lower but still elevated. This finding suggests a degree of autonom y of parathyroid secretion known to occur in cases of long-standing vitamin D deficiency. Myopathy, due to chronic vitamin D deficiency, probably cont ributes to immobility and ill health in a significant number of patients in the northern United States. An awareness of this condition may significant ly improve mobility and quality of life in patient populations vulnerable t o vitamin D deficiency.