Differences in vitamin D status and calcium metabolism in Saudi Arabian boys and girls aged 6 to 18 years: effects of age, gender, extent of veiling and physical activity with concomitant implications for bone health

Abstract

Objective: Few data exist looking at vitamin D status and bone health in schoolaged boys and girls from Saudi Arabia. The present study aimed to determine the extent of poor vitamin D status in school boys and girls aged 6-18 years and to examine if there was any difference in status with age, physical activity and veiling and concomitant effects on bone. Design: Cross-sectional study. Setting: Jeddah, Kingdom of Saudi Arabia. Subjects: A total of 150 boys (7-16 years) and 150 girls (6-18 years) from local schools were divided into age categories: 6-9 years (elementary school); 10-12 years (secondary school); 13-14 years (middle years); 15-18 years (high school). Results: Vitamin D status was significantly lower in girls than boys in all age groups (P , 0?01), with the 15-18-year-old girls having the lowest level (22?0 (SD 9?4) nmol/l) in comparison to the 15-18-year-old boys (39?3 (SD 14?0) nmol/l) and the 6-9-year-old girls (41?2 (SD 9?3) nmol/l). Parathyroid hormone status was highest in the 15-18-year-old girls in comparison to boys of the same age. A total of 64 % of 15-18-year-old girls had 25-hydroxyvitamin D (25OHD) status ,25 nmol/l in comparison to 31 % in the 13-14 years age category, 26 % in the 10-12 years category and 2?5 % in the 6-9 years category. No boys had 25OHD status ,25 nmol/l. Fully veiled girls had lower 25OHD status than partly veiled or unveiled girls (P , 0?05). Low 25OHD and high parathyroid hormone was associated with lower bone mass in the 6-9 years and 13-14 years age groups (P , 0?05). Conclusions: These data suggest significant hypovitaminosis D in older adolescent females, which is a cause for concern given that there is currently no public health policy for vitamin D in the Kingdom of Saudi Arabia.

Growth Profile and Its Association with Nutrient Intake and Dietary Patterns among Children and Adolescents in Hail Region of Saudi Arabia

“…Limited studies available on prevalence of child malnutrition from KSA suggest national data may alone be misleading in understanding the determinants and consequences and stoutly emphasize that it is crucial to focus on regional inequality which can be a result of ethnic as well as environmental conditions [10, 12, 19]. Few available studies documented the existence of prevalence of deficiencies of micronutrients like vitamin A, vitamin D, calcium, iron, iodine, and zinc among children of KSA (all mentioned nutrients known to influence growth and development of children) and also emphasized the need for higher number of studies to understand the wider impact of these deficiencies [22–25]. …”

Vitamin D Status in Secondary Care Patients

“…Evidence suggests that 25(OH) D blood levels should be maintained above 20 ng/ml to prevent rickets and osteomalacia 16 . However, levels should be above 30 ng/ml to maximize vitamin D's effect on calcium, bone and muscle metabolism 1 .…”

Vitamin D deficiency prevalence and risk factors among pregnant Chinese women

“…Additionally, clothing style may not be a major predictor of vitamin D deficiency levels under low ambient UVB level conditions. Saudi Arabian researchers have also found that vitamin D levels can be affected by clothing styles (24) . Pregnant women in their third trimester exhibited lower vitamin D levels than women in their first trimester of gestation (16·2 v. 17·0 ng/ml, P = 0·0243) in our study.…”