High prevalence of vitamin D deficiency in young children in a highly sunny humid country: a global health problem.

AIM: Several studies indicate a high prevalence of vitamin D deficiency among young populations. Information about the vitamin D status in young adult populations from the Middle East is scarce. The vitamin D status can be expected to be influenced by highly different factors between various countries in Europe, the Middle East and Asia. The aim of this study was to determine the prevalence of vitamin D deficiency in young Qatari children below 16 years of age.
METHODS: A cross-sectional study carried out among children below 16 years of age who visited the Primary Health Care Centers (PHCs). The survey was conducted over a period from August 2007 to March 2008. Qatari nationals, male and female, aged below 16 years. A random sample of 650 children who visited the PHC Centers was approached and parents of 458 children expressed their consent to participate in this study, corresponding to a response rate of 70.5%. Face-to-face interviews were based on a questionnaire that included variables such as socio-demographic information, life style, family history and feeding patterns during infancy, and clinical information as well as laboratory investigations for biochemical assessment of vitamin D status.
RESULTS: Of the total number of 458 children surveyed, 228 (49.8%) were males and 230 (50.2%) females. The prevalence of vitamin D deficiency among the studied Qatari children was (68.8%), mostly in the age group (11-16) years (61.6%). There was a significant difference between vitamin D deficient and normal children as compared to their age (P=0.013). Vitamin D deficiency was more common among girls (51.4%) than boys (48.6%). Exposure to sunlight was limited in both groups; but even lower in vitamin D deficient children (57.5%) than in normal children (70.6%). The duration of time spent outside was again low in both groups but significantly lower in vitamin D deficient children (23.5 minutes) compared to normal children (28.4 minutes). Low duration of time spent outdoors, breast feeding less than 6 months, a family history of diabetes mellitus and physical activity were significant predictors for vitamin D deficiency in Qatari children. Rickets, fractures, gastroenteritis and delayed milestones were all significantly higher in vitamin D deficient children.
CONCLUSIONS: The present study revealed that the prevalence of vitamin D deficiency is high in Qatari children and more common in Qatari girls. In the young population in Qatar, vitamin D deficiency appears to result from a combination of limitations in sunlight exposure and a low oral intake of vitamin D.