Vitamin D Deficiency in the Middle East and its Health Consequences for Children and Adults

Despite its abundant sunshine the Middle East, a region spanning latitudes from 12 degrees N to 42 degrees N allowing vitamin D synthesis year round, registers some of the lowest levels of vitamin D and the highest rates of hypovitaminosis D worldwide. This major public health problem affects individuals across all life stages including pregnant women, neonates, infants, children and adolescents, adults, and the elderly. Furthermore, while rickets is almost eradicated from developed countries, it is still reported in several countries in the Middle East. These observations can be explained by limited sun exposure due to cultural practices, dark skin color, and very hot climate in several countries in the gulf area, along with prolonged breast feeding without vitamin D supplementation, decreased calcium content of diets and outdoor activity, obesity, and lack of government regulation for vitamin D fortification of food, in several if not in all countries. The lack of population based studies renders estimates for the prevalence and incidence of rickets in the Middle East difficult, but several series from the region illustrate its dire consequences on growth and development. Furthermore, it is reported that 20-80% of apparently healthy individuals from several countries in this region have suboptimal vitamin D levels, depending on the cut-off used for defining hypovitaminosis D, the country, season, age group, and gender studied. Suboptimal levels have been associated with compromised skeletal health across age groups, and with poor muscular function and increased fall risk and osteoporotic fractures in the elderly. Studies detailing associations between low vitamin D levels and musculoskeletal health in the Middle East, and the impact of various treatment regimens are reviewed. Current recommendations for vitamin D derived from data in western subjects may not be sufficient for subjects from the Middle East, therefore suggestions for vitamin D replacement doses based on evidence available to-date are provided. Hypovitaminosis D is a major public health problem across all life stages in the Middle East with deleterious immediate and latent manifestations. Long term strategies to address this often silent disease should include public education, national health policies for screening and prevention through food fortification, and treatment through vitamin D supplementation.