G.P.26: Vitamin D deficiency myopathy in Egypt: A treatable myopathy

Abstract

Vitamin D deficiency could be due to decreased bioavailability (decreased intake or exposure to sunlight, urinary loss or malabsorption), abnormal metabolism (liver disease, renal disease) or abnormal target tissue response (vitamin D resistant or gastrointestinal disorders). Vitamin D deficiency is one of the causes of osteomalacic myopathy. To highlight the clinical and laboratory characteristics of vitamin D deficiency myopathy in Egypt and to discuss its therapeutic implications. All patients presented with gradual progressive limb-girdle weakness with or without bony pains, pains of limb muscles, low backache or joint pains. All patients had detailed clinical assessment, laboratory study (including serum calcium, phosphorus, alkaline phosphatase, total creatine kinase, parathyroid hormone and 25 (OH) vitamin D levels together with neurophysiological study and muscle biopsy in some cases. 30 patients were found to have vitamin D deficiency myopathy. Most of them were females, adolescents or early adults. Decreased dairy intake and decreased exposure to sunlight were the main causes for their illness. Most of them had stereotyped clinical presentation with marked deficiency of serum calcium, increased serum phosphorus and increased alkaline phosphatase levels. Parathyroid hormone serum level was high and vitamin D serum level was low. Muscle biopsy showed non-specific myopathic changes in studied specimens. Therapy with a combination of daily calcium and vitamin D intake greatly improve both pains and weakness within few months of all patients. Vitamin D deficiency myopathy is a common condition among females in Egypt due to decreased dairy intake and exposure to sunlight. Clinicians must take attention to this type of myopathy as it is a treatable myopathy.