Vitamin D deficiency as the primary cause of musculoskeletal complaints in patients referred to rheumatology clinic: A clinical study

Abstract

ObjectiveTo study vitamin D deficiency as the primary cause of musculoskeletal complaints in rheumatology clinic. MethodsAdult patients presenting with ‘non-inflammatory’ musculoskeletal pain to our rheumatology clinic between May 2009 and April 2011 underwent estimation of serum 25-hydroxyvitamin D [25(OH)D] and those with level < 20 ng/ml were recruited. Hypothyroidism, painful neuropathies, chronic kidney disease, malignancies, chikungunya, HIV, HCV and HBV were excluded. All study patients underwent complete physical examination and baseline estimation of serum calcium, phosphorus, alkaline phosphatase and PTH besides routine tests. Study patients received treatment with oral cholecalciferol and calcium and were re-assessed clinically and biochemically after 8 weeks. Serum 25(OH)D levels were also estimated in 92 asymptomatic controls. ResultsThirty patients were found eligible for the study after screening a total of 95 (Male/Female: 12/18; mean age: 42.3 ± 13.2 years). Polyarthralgia was the commonest presenting complaint (46.6%). Other symptoms included myalgia, bone pains and chronic widespread pain. Physical examination showed joint and muscle tenderness in 10 patients each and joint swelling in one. Paired biochemical results at baseline and 8 weeks were: 25(OH)D (ng/ml) = 5.84 ± 2.71 and 34.45 ± 12.98, calcium (mg/dL) = 9.06 ± 0.58 and 9.16 ± 0.63, phosphorus (mg/dL) = 3.65 ± 0.95 and 3.84 ± 0.70. Paired median [IQR] values for alkaline phosphatase and PTH were 89 [66–181] and 68 [55–138] units/L, and 69.2 [47.6–106] and 38.8 [25–60] pg/ml respectively. Treatment was successful in all except 4. Improvement was found to be sustained in all cases at 6 months follow up. Although 75% of controls also had biochemical evidence of vitamin D deficiency, their vitamin D levels were significantly higher. ConclusionsVitamin D deficiency is frequently the sole cause of polyarthralgia, myalgia, bone pain and chronic widespread pain in patients referred to rheumatology clinic. Referring physicians ought to have a lower threshold for this eminently curable condition.