Prevalence of 25-hydroxyvitamin D deficiency in Korean patients with anemia

We investigated the prevalence and risk factors for vitamin D deficiency in Korean patients with anemia.

We included 200 anemic patients and 300 controls. Anemia was defined according to the WHO criteria. Serum 25-hydroxyvitamin D [25(OH)D] was measured using an electrochemiluminescence immunoassay. We compared serum 25(OH)D levels based on the presence and subtypes of anemia.

We found that 91% (182/200) and 87.3% (262/300) of patients exhibited 25(OH)D inadequacies (<20 ng/ml) in the anemic (median hemoglobin (Hb), 9.6 g/dl) and control groups (median Hb 13.8 g/dl), respectively. The prevalence of 25(OH)D deficiency (<12 ng/ml) was significantly higher in the anemic group than in the control group (52.5% (105/200) vs. 25% (75/300), P < 0.0001), with an odds ratio of 3.316 (95% CI, 2.265-4.854; P < 0.0001). The prevalence of 25(OH)D deficiency was not different among anemia subtypes. Female gender and high C-reactive protein (CRP) were associated with vitamin D deficiency in anemic group.

This study demonstrates that vitamin D deficiency is associated with anemia. Therefore, the measurement of serum 25(OH)D levels and appropriate vitamin D supplementation should be considered in anemic patients, particularly in females and patients with high CRP level.