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