Risk factors of low vitamin D status in adolescent females in Kuwait: implications for high peak bone mass attainment

A Summary Risks of low vitamin D status in Kuwaiti adolescent girls are high parathyroid hormone (PTH), high waist/hip ratio, veiling and not having a private room. Low vitamin D status is likely to have a negative impact on their bone mass and accrual. Introduction Low serum 25-hydroxyvitamin D (25OHD) levels are repeatedly found in females in the Middle East, which is a cause for concern particularly for adolescent females. This is because vitamin D has been shown to promote bone mineral accrual in adolescence. Purpose The aim of this study was to assess the risk factors of low vitamin D status in adolescent females and to assess its impact on their bone mass. Methods Serum 25OHD and PTH were measured in 232 females. Anthropometric measurements and skin colour were obtained. Bone measurements at the lumbar spine were performed using dual-energy x-ray absorptiometry (DXA). Data on food intake, physical activity (PA) and sun exposure were taken. Binary logistic regression was used to assess the risk factors of serum 25OHD levels <25 nmol/L and multiple linear regression was used to assess the predictors of bone mineral variables. Results Median 25OHD was 19.4 nmol/L (IQR 16.4-23.68), among which 98.7 % obtained <50 nmol/L. PTH >7 pmol/L (odds ratio (OR) 4.3; 95 % CI 1.8, 10.2), not having a private room (OR 3.7; 95 % CI 1.4, 9.8), veiling (OR 2.4; 95 % CI 1.1, 5.5) and waist/hip ratio >0.75 (OR 2.1; 95 % CI 1.0, 4.3) were risk factors of low vitamin D status, whereas, height, weight, month since menarche, PTH, animal protein intake and PA were independent predictors of bone mineral content (p<0.05). Conclusion Low vitamin D status is prevalent in Kuwaiti adolescent females, which may have a negative impact on their bone mineralization and accrual. Further investigation is needed to reveal the underlying causes.