Vitamin D effect on umbilical cord blood characteristics: a comparison between African Americans and Caucasians

BACKGROUND Umbilical cord blood (UCB) units collected from African Americans (AAs) have lower total nucleated cell (TNC) and CD34+ cell counts and are more likely to disqualify for banking compared to other ethnic groups. Furthermore, AAs have higher prevalence of 25-hydroxyvitamin D (25(OH)D) deficiency. Given the importance of 25(OH)D in hematopoiesis, we examined the racial differences in UCB unit 25(OH)D content and its correlation with UCB cellular characteristics. STUDY DESIGN AND METHODS A total of 119 UCB units that did not meet the TNC count banking criteria were analyzed. Fifty-one UCB units were collected from AA mothers and 68 from Caucasian mothers. We analyzed UCB volume, hematocrit (Hct), TNCs, mononuclear cells (MNCs), CD34+ cells, plasma 25(OH)D concentration, and progenitor clonogenic capacity measured by colony-forming cell (CFC) assay. RESULTS Compared to Caucasians, AAs had significantly lower UCB 25(OH)D levels (p