Issues Related To Cord Blood Vitamin D Levels Were Measured And Children's Bone Health

Part 1. Cord blood vitamin D and relationship with the nutritional vitamin D status of pregnant woman[Objective] To understand the status of Vitamin D in cord blood and discuss the influence factor.[Method] We selected 102 newborns who were born in Jiangsu province hospital. Their base information and the supplement of vitamin D and calcium in the third trimester were noted. The 25-(OH)D in cord blood and mothers were measured partly by Euzymelinked immunosorbent assay.[Results] Cord blood 25-(OH)D was (44.34±17.10)nmol/L. We classified Vitamin D deficient as 25-(OH)D <30nmol/L. 16 newborns (15.7%) had their cord blood 25-(OH)D value under the limit. In the 30 mother-infant pairs, the mothers'serum 25-(OH)D was (39.25±15.14)nmol/L and the cord blood 25-(OH)D was(37.76±12.15)nmol/L, and they had significant positive correlation (r=0.842,P<0.001). Pregnant woman who had adequate intake of vitamin D and formula milk (>3 month) had newborns with higher cord blood 25-(OH) D (P>0.05).[Conclusion] The cord blood 25-(OH)D in this study was significant higher than black and Iranian newborns', but lower than Europe and the United States'. 25-(OH)D status of pregnant woman determined the cord blood 25-(OH)D. The supplement of vitamin D and formula milk for pregnant women can improve the level of cord blood 25-(OH) D. Part 2.Cord blood lipids and adiponection and relationship with vitamin D[Objective] To understand the status of lipids and adiponection in cord blood, and to determine the relationship among vitamin D and lipids, adiponection.[Method] We selected 102 newborns who were born in Jiangsu province hospital. The gender, gestational age and birth weight of the newborns were noted. The cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), adiponection and 25-hydroxyvitamin D (25-(OH) D) in cord blood were detected.[Results] TC,TG,HDL-C,LDL-C,adiponection and 25-(OH)D level were (1.84±0.66)mmol/L,(0.27±0.21)mmol/L,(0.71±0.21)mmol/L,(0.75±0.35)mmol/L,(30.27±7.32)mg/L and(44.34±17.10)nmol/L, respectively. There were no associations between 25-(OH)D and adiponection,25-(OH)D and lipids, adiponection and lipids(p>0.05). Boys'HDL-C was lower than girls'. Boys'adiponection was higher than girls'. The lipids and adiponection in cord blood were not significantly different between newborns with different gestational age and birth weight.[Conclusion] TC,TG,HDL-C,LDL-C,adiponection in cord blood were not relative to vitamin D,gestational age and birth weight. HDL-C and adiponection were different between boys and girls. Part 3. Cord blood vitamin D and bone mineral density at age 3 and 6 months[Objective] To explore the relationship between cord blood vitamin D and bone mineral density(BMD) when the infants were 3 and 6 month-old.[Method] We selected 102 newborns who were born in Jiangsu province hospital. The 25-(OH)D of cord blood was detected. When the infant was in 3 and 6 month-old, the BMD were determined and the information of feeding patterns, vitamin D supplementation, eczema, respiratory tract infection were noted.[Results] The BMD of infants with different feeding patterns were not significant different at age 3 and 6 months (P>0.05).All the infants followed up added vitamin D according to current recommendations (400IU/d).The cord blood 25-(OH) D was not related to the BMD of infants both at age 3 and 6 months (P>0.05), and eczema, respiratory tract infection before 6 months(P>0.05).[Conclusion] The cord blood vitamin D didn't appear to influence the BMD before 6 month-old. Part 4. Bone mineral density of infant under 2 in Nanjing[Objective] To understand the bone mineral density (BMD) of infants under 2 in Nanjing monitored by quantitative ultrasound and analyze the outcome evaluated by Asian and Chinese criterion.[Method] We selected 2024 healthy infants in Nanjing and used the quantitative ultrasound system to get their speed of sound (SOS) in bone. Then use Asian and Chinese criterion to evaluate the SOS which were noted as ZA and ZC.[Results] The SOS of infants was increased with chronological age (r=0.870,P<0.001).We classified Z≤-1 as BMD abnormal. ZA had 20.4% and ZC had 66.9% below the cutoff and they had significant difference (P<0.001),and ZA>-1(t=39.357,p<0.001),ZC<-1(t=-17.501,p<0.001).The SOS had positive correlation with weight and length (r=0.680 and r=0.810,p<0.001) and negative correlation with the BMI(r=-0.256,p<0.001) of the infants.[Conclusion] The BMD of infants under 2 was increased with chronological age. The obese infants were more vulnerable to be BMD deficiency. The Asian criterion was loose and Chinese criterion was strict to evaluate the infants in Nanjing. So the criterion for local children is needed to establish.