Vitamin D supplementation may improve back pain disability in vitamin D deficient and overweight or obese adults

• Published in: The Journal of steroid biochemistry and molecular biology Vol. 185; pp. 212 - 217
• Main Authors: Brady, Sharmayne R.E., Naderpoor, Negar, de Courten, Maximilian P.J., Scragg, Robert, Cicuttini, Flavia, Mousa, Aya, de Courten, Barbora
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-01-2019; Elsevier BV
• Subjects: 25-Hydroxyvitamin D; Adult; Back pain; Back Pain - diet therapy; Body Mass Index; Body weight; Calcium-Regulating Hormones and Agents - therapeutic use; Cholecalciferol - therapeutic use; Chronic pain; Clinical trials; Dietary supplements; Double-Blind Method; Female; Humans; Male; Nutrient deficiency; Obesity; Obesity - pathology; Overweight; Overweight and obesity; Physical activity; Randomised controlled trial; Risk factors; Surveys and Questionnaires; Vitamin D; Vitamin D - analogs & derivatives; Vitamin D - blood; Vitamin D Deficiency - diet therapy; Vitamin deficiency; Back pain; Vitamin D; Overweight and obesity; Randomised controlled trial
• ISSN: 0960-0760; 1879-1220
• DOI: 10.1016/j.jsbmb.2018.09.005

•This trial investigated the effects of vitamin D supplementation on back pain.•Vitamin D in severely deficient, overweight/obese adults reduced back pain disability.•Vitamin D testing may be warranted in this subgroup, but further studies are suggested.
Back pain is currently the greatest cause of disability worldwide, and there are very limited therapeutic options available. Vitamin D deficiency and obesity are both risk factors for back pain. The few randomised controlled trials examining the effects of vitamin D supplementation on back pain have methodological limitations and largely include non-vitamin D deficient participants. Thus, the aim of this study was to determine whether vitamin D supplementation improves back pain symptoms in vitamin D deficient and overweight or obese, otherwise healthy adults. Sixty-five overweight or obese adults (BMI ≥ 25 kg/m2) with vitamin D deficiency (25-hydroxyvitamin D [25(OH)D] concentrations ≤50 nmol/L) were randomised to a bolus oral dose of 100,000 IU followed by 4000 IU cholecalciferol/day or matching placebo for 16 weeks. We measured 25(OH)D concentrations (chemiluminescent immunoassays) and self-reported back pain (Chronic Pain Grade Questionnaire) before and after the intervention. Lifestyle habits including sun exposure, physical activity, and diet were collected using questionnaires. Fifty-four participants completed the study, of which 49 had complete data for back pain and were included in the present analyses (31 M/18 F; mean ± SD age: 31.8 ± 8.9 years; BMI: 31.1 ± 4.5 kg/m2). After the 16-week intervention, 25(OH)D levels increased significantly with vitamin D supplementation compared with placebo (55.7 ± 20.9 versus 3.9 ± 14.4 nmol/L, respectively, p < 0.001). There were no significant differences between vitamin D and placebo groups in change in back pain intensity or disability scores (all p > 0.05). However, in those with 25(OH)D concentrations <30 nmol/L at baseline (n = 20), there was a significantly greater reduction in back pain disability scores in the vitamin D group compared with placebo, after adjusting for important covariates known to affect vitamin D status and/or back pain (b [95%CI] = -11.6 [-22.4, -0.8], p = 0.04). Our findings suggest that vitamin D supplementation in overweight or obese and markedly vitamin D deficient adults (25(OH)D <30 nmol/L) may improve back pain disability. Although treating severe vitamin D deficiency is recommended for optimising bone health, this study suggests it may also improve back pain. Hence, testing for vitamin D deficiency in those with back pain who are overweight or obese may be warranted.