Background: Identified aetiological factors for chronic widespread pain (CWP) are largely related to emotional and behavioral factors, but current management leads to modest improvement in symptoms. Vitamin D deficiency has been suggested as a new modifiable risk factor for CWP.
Objective: To examine the association between vitamin D status (measured by 25-hydroxyvitamin D (25(OH)D)) and CWP in a nationwide population sample of white British adults, accounting for potential mediating and confounding lifestyle factors.
Methods: 9,377 participants born 1 week in March 1958, in England, Scotland or Wales and completing a biomedical assessment at age 45; 6,824 eligible participants had data on 25(OH)D and completed pain manikins.
Results: Prevalence of CWP varied by 25(OH)D concentration in women but not in men, with the lowest prevalence observed for women with 75-99 nmol/l:
- 14.4% for less than 25 nmol/l, - 14.8% for 25-49 nmol/l, - 11.6% for 50-74 nmo/l, - 8.2% for 75-99 nmol/l - and 9.8% for participants with 100 nmol/l or more.
There was an interaction between 25(OH)D concentration and gender in relation to CWP (interaction, p = 0.006), which was not fully explained by differences in lifestyle or social factors (adjusted interaction, p = 0.03).
For women, the association between 25(OH)D concentration and chronic widespread pain persisted after full adjustment (odds ratio (OR) for less than 75 nmol/l vs 75-99 nmol/l 1.57, 95% CI 1.09 to 2.26), while no evidence for an association was apparent in men (OR = 1.03, 95% CI 0.75 to 1.43). [Note: an odds ratio of 1.0 would mean no difference in odds. The OR of 1.57 for women means a 57% greater odds of having chronic widespread pain for those with 25(OH)D concentration of less than 75 nmol/l.]
Conclusions: Current vitamin D status was associated with chronic widespread pain in women but not in men. Follow-up studies are needed to evaluate whether higher vitamin D intake might have beneficial effects on the risk of CWP.
Source: Annals of the Rheumatic Diseases, Jun 2009;68(6):817-22. PMID: 18697776, by Atherton K, Berry DJ, Parsons T, Macfarlane GJ, Power C, Hypponen E. MRC Centre of Epidemiology for Child Health, UCL Institute of Child Health, London, UK.