Predictors of vitamin D deficiency and insufficiency in adult Bahrainis: a cross-sectional study.

OBJECTIVE: 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. DESIGN: A cross-sectional study. SETTING: Blood transfusion volunteers at a blood bank. SUBJECTS: 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. RESULTS: 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). CONCLUSIONS: 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.

Association of vitamin D deficiency and hyperparathyroidism with anemia: a cross-sectional study.

Vitamin D deficiency and anemia are common in the Middle East, and vitamin D deficiency and hyperparathyroidism have been reported to be associated with an increased prevalence of anemia. In this study, the hypothesis that vitamin D deficiency and hyperparathyroidism may be associated with anemia in a Bahraini population was tested. Association of hyperparathyroidism and vitamin D levels (deficiency and insufficiency) with anemia was investigated in 421 Bahrainis (213 males and 208 females). In females, the prevalence of anemia was significantly associated with vitamin D deficiency independent of parathyroid hormone levels (odds ratio: 2.9; 95% confidence interval: 2.3-10.5; P = 0.001). In females, the prevalence of anemia appeared to be significantly associated with hyperparathyroidism (odds ratio: 2.1; 95% confidence interval: 1.2-3.7; P = 0.01); however, this significant association disappeared when adjusted for vitamin D deficiency (odds ratio: 1.6; 95% confidence interval: 0.75-6.5; P = 0.154). Results from this study suggest that vitamin D deficiency is independently associated with anemia in females but not males. Further studies to determine whether vitamin D supplementation could be used to treat anemia are warranted.