High prevalence of hypovitaminosis D has been reported to be common in different regions of the Middle East. The objective of the present study was to examine the predictors of vitamin D deficiency and insufficiency in Bahrainis.

A cross-sectional study.

Blood transfusion volunteers at a blood bank.

Serum levels of total 25-hydroxyvitamin D, bone markers and other parameters such age, sex, season and clothing style in the 500 healthy Bahrainis were investigated.

In the entire cohort the prevalence of vitamin D deficiency was 49·4 % and the relative risk of vitamin D deficiency increased significantly by 1·1, 1·2, 1·5, 1·7 and 1·2 fold with younger age group (P = 0·03), hyperparathyroidism (P = 0·01), low serum Ca (P < 0·001), warm and hot months of the year (P < 0·0001) and female sex (P = 0·002), respectively. In females the prevalence of vitamin D deficiency was 67·6 % and the relative risk of vitamin D deficiency increased significantly by 1·1, 1·2, 1·2, 1·2 and 1·4 fold with younger age group (P = 0·04), hyperparathyroidism (P = 0·03), low serum Ca (P = 0·001), warm and hot months of the year (P = 0·001) and conservative clothing style (P = 0·04), respectively. In contrast, in males the prevalence of vitamin D deficiency was 31·2 % and the relative risk of vitamin D deficiency was increased by 1·6 fold in warm and hot months of the year (P < 0·0001).

High prevalence of low circulating levels of vitamin D and the relative risk factors associated with vitamin D deficiency and insufficiency observed in the present study suggest an urgent need for public health interventions including vitamin D food fortification in Bahrain.