relationship between unexplained arthralgia and vitamin d deficiency: a case control study.

arthralgia is a common presenting symptom of many rheumatic diseases. vitamin d deficiency may lead to progression of skeletal symptoms to definite disease in susceptible subjects. this study was conducted to determine the relationship between vitamin d deficiency and unexplained arthralgia. patients with arthralgia not related to a definite clinical condition were selected prospectively among subjects presented to a rheumatology clinic. serum 25-hydroxyvitamin d (25-ohd) was measured by elisa method and levels less than 20 ng/ml were considered as deficient levels. serum 25-ohd levels and proportion of 25-ohd deficiency was compared in patients versus control. the association of serum 25-ohd and arthralgia was assessed by calculation of odds ratio (or) using regression analysis. 167 patients with mean age of 38 ± 13.3 and 283 controls with mean age of 42.6±14.37 years (p=0.001) were studied. in patients mean serum 25-ohd was lower and proportion of deficiency was higher (p=0.001 for both).serum 25-ohd deficiency was associated with 3.01 times increased risk of arthralgia (or=3.01, 95% ci, 2.0- 4.25, p=0.001). after adjusment for age and sex, the risk of arthralgia remained significan at or= 2.71(95%ci, 1.79-4.11,p=0.001).the odds of arthralgia decreased with increasing serum 25-ohd from or=3.48 (95% ci,197-6,p=0.001) at serum <10 ng/ml to 3.39 (95%ci,1.93-5.98, p=0.001) at 10-19.9; and 1.31 (95%ci, 0.69-2.5, p=0.42) at 20-29.9 ng/ml. these findings indicate significant association of vitamin d deficiency and arthralgia. regarding vitamin d deficiency as an environmental factor for development or progression of rheumatic diseases, this study justifies identification and correction of vitamin d deficiency in patients with arthralgia.