Background: Deficiency of vitamin D has been reported in patients with many types of musculoskeletal pain. The present study was designed to determine the association between serum 25-hydroxyvitamin D [25-(OH)D] deficiency and nonspecific skeletal pain.
Methods: A total of 276 patients with nonspecific skeletal pain at different regions of the skeletal system diagnosed as leg pain, widespread pain, arthralgia [joint pain], rib pain, back pain and fibromyalgia were compared with 202 matched controls with regard to mean serum 25-(OH)D level and 25-(OH)D deficiency.
Serum 25-(OH)D was measured by enzyme-linked immunosorbent assay method and levels < 20 ng/mL were considered as deficient. Nonparametric one-way analysis of variance, Kruskal Wallis and Wilcoxon tests were used for group comparisons. Multiple logistic regression analysis with calculation of adjusted odds ratio (OR) and 95% confidence interval (95% CI) were performed to determine associations.
Results: In patients with nonspecific skeletal pain the mean 25-(OH)D was significantly lower (P = 0.0001) [That is, the probability (P) that this association resulted by chance was less than 1 in 10,000] and the proportion of 25-(OH)D deficiency was significantly higher (63.4% vs. 36.1%, P = 0.0001) compared with controls.
There was a significantly positive association between 25-(OH)D deficiency and skeletal pain (OR = 2.94, 95% CI = 1.01–4.3, P = 0.0001). [Note: an odds ratio of 1.0 would have signified no greater odds of skeletal pain among those with a vitamin D deficiency. The OR of 2.94 indicates the deficient subjects were nearly 3 times more likely to have skeletal pain. And the probability (P) that this association resulted by chance is less than 1 in 10,000.]
The strength of association varied across the groups with:
• Strongest association observed with leg pain (OR = 7.4; 95% CI = 3.9–13.9, P = 0.0001) [Deficient subjects 7.4 times as likely to have leg pain.]
• Followed by arthralgia [joint pain] (OR = 3.9, 95% CI = 2.1–7.1, P = 0.0001)
• And widespread pain (OR = 2.8, 95% CI = 1.1–6.6, P = 0.020)
• But no association with back pain and fibromyalgia. [Presuming ‘widespread pain’ was considered mainly pain in bones/joints and FM pain typically muscle pain.]
There was a greater positive association in women compared with men (OR = 2.1, 95% CI = 1.1–4.3, P = 0.001).
The results of this study indicate a positive association of vitamin D deficiency with a variety of nonspecific bone pain, particularly in women.
More studies with larger samples are required to confirm these findings. Increasing serum vitamin D to sufficient levels and longitudinal follow-up of patients may provide further evidence in relation to vitamin D deficiency and skeletal pain.
Source: International Journal of Rheumatic Diseases, Oct 2010;13(4) pp 340-346. DOI: 10.1111/j.1756-185X.2010.01561.x, by Heidari B, Shirvani JS, Firouzjahi A, Heidari P, Hajian-tilake KO. Department of Medicine, Division of Rheumatology, Rouhani Hospital, Babol University of Medical Sciences, Babol, Iran. [Email: firstname.lastname@example.org]