Vitamin D Deficiency and Clinically Detected Scoliosis among Male Adolescents at High-Altitude Area in Southwestern Saudi Arabia

BACKGROUND AND OBJECTIVES: Reports suggest that Vitamin D deficiency (VDD) is common and is a general health challenge worldwide and at high altitude in particular. AIM: The objectives were to explore Vitamin D status, to examine the association of VDD and clinically detected scoliosis, and to find a cutoff point of Vitamin D level predicting clinical scoliosis in Abha City (high-altitude area). METHODS: A nested case–control design was conducted among a screened population of 417 male adolescents from intermediate and secondary schools in Abha City, Southwest Saudi Arabia. From the surveyed adolescents, 62 cases with clinically detected scoliosis and 205 age-matched controls without scoliosis were selected. For both groups, serum level of 25-hydroxyvitamin D was assessed by standardized technique. RESULTS: More than two-thirds (68.5%) of male adolescents suffered from VDD (<25 nmol/L). The risk of clinical scoliosis was significantly higher among adolescents with VDD compared to those without deficiency (grade adjusted odds ratio = 6.88, 95% CI: 2.63–17.99). Receiver operating characteristic curve analysis showed acceptable discriminative ability of serum Vitamin D (area under the curve = 0.702) to predict scoliosis at a threshold value of ≤20.2 nmol/L. CONCLUSIONS: Overall levels of Vitamin D in the study adolescents suggest a high prevalence of VDD at high-altitude area in Southwest Saudi Arabia. There is evidence for a positive association between VDD and clinically detected scoliosis. A threshold cutoff value of 20.2 nmol/L has been identified to predict clinically detected scoliosis. The role of possible preventive effect of Vitamin D supplementation should be considered by school health authorities.