Vitamin D levels in relation to low back pain during adolescence.

This study aimed to investigate the association between 25-hydroxyvitamin D (25(OH)D) level and Low back pain (LBP) among adolescents while adjusting for potential confounders pertinent to this age group including the weight of school bags, body mass index and physical activity. A cross-sectional study was conducted on randomly selected 760 adolescents in middle schools. Data on LBP and the risk factors for LBP were collected from the parents by self-administered questionnaire and from adolescents by face-to-face interview. Blood samples were tested in an accredited laboratory; and 25(OH)D was measured using liquid chromatography-tandem mass spectrometry. The life-time prevalence and the 6-month prevalence of LBP were 32.28% (95%CI: 28.97-35.73 %) and 21.26% (95%CI:18.40-24.33%), respectively. There was no difference in the geometric mean of 25(OH)D between those with and without LBP in the past six months, 28.50 nmol/L and 30.82 nmol/L, respectively (p= 0.122). There was no association between 25(OH)D and LBP in the univariable or multivariable analysis whether 25(OH)D fitted as a continuous, or as a categorical variable. We found no association between vitamin D level and LBP in adolescents in an area with high prevalence of vitamin D deficiency. Although it is important to have sufficient vitamin D levels during adolescence for several other health benefits, we concluded that vitamin D is not a major determinant for LBP among adolescents in our setting.