Résumé
Objective To determine the amount of serum Vitamin D in premature infants,and to investigate its correlation with bone quantitative ultrasound measurement.Methods The serum of premature infants born between 2013 March and 2014 March in the Maternal and Children Health Hospital of Huadu District in Guangzhou were collected,and serum 25-hydroxyvitamin D [25-(OH) D] level was measured by using chemiluminescence immunoassay,while Omnisense quantitative ultrasound was used to measure bone speed of sound(SOS) in the middle area of the left tibia.According to gestational age,the participants were divided into A,B and C groups(28-32 weeks,32 +1-34 weeks,34 + 1-36 +6 weeks,respectively).The levels of 25-(OH)D and SOS were compared and the correlation between them was analyzed.Results The amount of 25-(OH) D of the 3 groups was (41.65 ± 21.15) nmoL/L,(47.15 ± 19.78) nmol/L,and (49.35 ± 19.93) nmol/L,respectively,and the differences among the 3 groups were statistically significant (F =4.441,P =0.012).The ratio of vitamin D abundant or not (insufficiency including deficiency and lack) in preterm among the 3 groups were compared,and the differences among the 3 groups were statistically significant(x2 =11.38,P =0.023).SOS of the 3 groups were (2 787.85 ± 123.01) m/s,(2 865.12 ± 129.44) m/s and (2 908.59 ± 124.01) m/s,respectively,and the differences among the 3 groups were statistically significant (F =28.716,P =0.000).There was a positive correlation between 25-(OH) D and SOS (r =0.084,P =0.024).Conclusions Level of Vitamin D in premature infants is generally inadequate.The smaller the gestational age,the higher the occurrence rate.Vitamin D levels and SOS are significantly positively correlated,and both of them increase with gestational age.