Maternal-neonatal vitamin D status and related factors / 中华儿科杂志

<p><b>OBJECTIVE</b>To determine the relationship between maternal and neonatal vitamin D status and related factors.</p><p><b>METHOD</b>Serum 25-(OH)D levels were measured by ELISA in 499 pregnant women at 30 - 37 weeks gestation and in cord blood of their infants born at term (37 - 42 wk gestation) in Southeastern China at 28.9°N latitude. One-way analysis of variance (ANOVA) was used to explore maternal and neonatal vitamin D levels by season. Pearson linear and linear regression of partial correlation was used to analyze the relationship between maternal and neonatal 25-(OH) D levels. The multiple factors related to maternal vitamin D status was assessed by binary logistic regression.</p><p><b>RESULT</b>The levels of serum 25-(OH)D were (33.0 ± 13.4) nmol/L in mothers and (31.0 ± 12.5) nmol/L in their newborns. Serum 25-(OH)D < 50 nmol/L was shown in 88.8% of mothers and 91.2% of their neonates. Both maternal and neonatal 25-(OH)D levels varied with season (Ps = 0.000). Vitamin D level was the lowest in spring, with the 25-(OH)D concentration < 50 nmol/L in 98.6% of mothers and 99.3% of their neonates. The highest vitamin D level was presented in fall, but there were still 64.0% of mothers and 75.0% of neonates with 25-(OH)D < 50 nmol/L. Except for season, calcium-vitamin D supplement and intake of egg ≥ 600 g per week during pregnancy benefited to improve maternal vitamin D level [25-(OH)D ≥ 50 nmol/L] [OR = 2.3 (95%CI:1.0, 5.3), 3.4 (95%CI:1.2, 9.9) respectively]. There was a positive correlation between maternal and neonatal 25-(OH)D measures in the sample as a whole (r = 0.45, P = 0.000, N = 499), the correlation was of no statistical significance when maternal serum 25-(OH)D was ≤ 25 nmol/L.</p><p><b>CONCLUSION</b>Hypovitaminosis D was common in late pregnant mothers and their newborns in southeastern China, especially in spring. Vitamin D supplement and intake of vitamin D-rich food were beneficial to improvement of maternal vitamin D level. There was a moderate and positive correlation between maternal and neonatal 25-(OH)D concentrations in this population. The correlation was lost when maternal serum 25-(OH)D ≤ 25 nmol/L.</p>

Value of soluble transferrin receptor in the diagnosis of iron deficiency in children / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the prevalence of iron deficiency in children between 6 months and 7 years and to study the diagnostic value of soluble transferrin receptor (sTfR) for iron deficiency in the children.</p><p><b>METHODS</b>A total of 502 healthy children between 6 months and 7 years from Hangzhou City of Zhejiang Province were enrolled. Serum sTfR, serum ferritin (SF), serum iron (SI), total iron blinding capacity (TIBC), zinc protoporphyrin (ZPP), Hb, MCV and CRP levels were measured.</p><p><b>RESULTS</b>The prevalence rate of iron deficiency was 19.5% in children at ages of 6 months to 7 years. The prevalence rate of iron deficiency was the highest in infants (≤1 year old; 34.7%), followed by in toddlers (1-3 years old; 19.4%) and preschoolers (3-7 years old; 14.0%). The mean serum sTfR level in infants (2.02±0.73 mg/L) was significantly higher than that in toddlers (1.68±0.40 mg/L) and preschoolers (1.67±0.29 mg/L) (P<0.05).The best cut-off value of serum sTfR for the diagnosis of iron deficiency was 2.02 mg/L in infants (sensitivity: 70.3%, specificity: 82.2%). The best cut-off value was 1.85 mg/L in toddlers (sensitivity: 71.7%; specificity: 86.4%), and that was 1.85 mg/L in preschoolers (sensitivity: 77.8%; specificity: 88.6%). Serum sTfR was correlated with SF (r=0.107, P<0.05), TIBC (r=0.276, P<0.01), TS (r=-0.139, P<0.05), ZPP (r=0.175, P<0.01) and MCV (r=-0.140, P<0.01).</p><p><b>CONCLUSIONS</b>Iron deficiency is more prevalent in infants ≤1 year old. The mean serum level and the cut-off value of sTfR in infants are higher than in toddlers and preschoolers. Serum sTfR is an effective index for the diagnosis of iron deficiency in children, especially in infants≤ 1 year old.</p>