Parameters of vitamin A (VA) status in children with sickle cell disease (SCD)

Abstract

VA status is compromised and there is chronic inflammation in SCD. We examined effects of VA (300‐600 µg/day; n=22) or VA + zinc (AZ; 300‐600 µg VA + 10 mg Zn/d; n=16) vs placebo (PL; n=21) on serum VA and its transporters in SCD children (7.7 ± 2.8 y). Serum samples were analyzed for retinol concentrations (ROH) at baseline and after 3, 6 or 12 mo of supplementation and for retinol‐binding protein (RBP) and transthyretin (TTR) at baseline and 3 or 12 mo. ROH was low at baseline (0.64 ± 0.14 µmol/L, n=59) compared to the cut‐off for VA deficiency (< 0.70 µmol/L). In children with low baseline ROH (< 0.70 µmol/L), ROH was significantly higher in AZ than in PL but VA alone did not significantly increase ROH (0.626 ± 0.117 [AZ], 0.606 ± 0.125 [VA], 0.574 ± 0.143 µmol/L [PL]). Serum ROH was significantly higher at 3 (5 % increase) and 12 mo (6.5 %) vs baseline in children with low baseline ROH. There InInThwere no differences among groups in the molar ratio of ROH:RBP, which was low in all subjects (0.422 ± 0.102). Higher molar ratios of ROH:RBP were associated with lower molar ratios of RBP:TTR (p=0.000). Our findings indicate that, in spite of VA or VA + zinc supplementation, ROH and ROH:RBP were not normalized in SCD children. Funding provided by: Comprehensive Sickle Cell Center (NIH: 5 U54 HL070596), CTRC (UL1‐RR‐024134), and the Nutrition Center of the Children's Hospital of Philadelphia.