Objective To systematically evaluate the correlation between vitamin D deficiency in early pregnancy and the outcome of preterm birth.Method PubMed,Embase,the Cochrane Library,Web of Science,Ebsco,CBM,CNKI and Wanfang Data databases were searched to collect cohort studies and case-control studies on the correlation between vitamin D deficiency in early pregnancy and preterm birth outcomes,and the retrieval time was from the establishment of the database to June 2019.Two researchers independently reviewed the literature,extracted the data and evaluated the risk of bias in the included studies.RevMan 5.3 software was used for Meta analysis.Result A total of 6 cohort studies and 3 nested case-control studies were included.A total of 30 891 newborns were included,including 1 912 premature infants.3 Chinese articles and 6 English articles were reviewed including three studies from China,three from North America,two from Europe and one from Australia.The diagnostic criteria for vitamin D deficiency and preterm birth were similar in these studies.After adjusting for age,race and other confounding factors,Meta-analysis results showed that vitamin D deficiency in early pregnancy did not increase the risk of preterm birth (OR =1.04,95％ CI 0.90 ～ 1.20,P =0.63).Subgroup analysis were conducted according to the study type,measurement method and regional population,and the results were consistent with the overall results.No significant publication bias was found in the meta-analysis results.Conclusion Current evidence suggests that vitamin D deficiency in early pregnancy has no significant influence on preterm birth.

Objective:To investigate the application value of individualized full-course nutritional intervention in neoadjuvant concurrent chemoradiotherapy (nCRT) for locally advanced Siewert type Ⅱ and Ⅲ adenocarcinoma of esophagogastric junction (AEG).Methods:The perspec-tive randomized control study was conducted. The clinicopathological data of 90 patients with locally advanced Siewert type Ⅱ and Ⅲ AEG who underwent nCRT in the Fourth Hospital of Hebei Medical University from February 2012 to December 2018 were selected. Patient were divided into two groups with 1:1 according to random number table. Patients undergoing nCRT combined with individualized full-course nutritional intervention were allocated into experimental group, and patients undergoing nCRT combined with common nutritional intervention were allocated into control group. Observation indicators: (1) grouping situations of the enrolled patients; (2) changing situations of nutritional status and quality of life of patients in nCRT and preoperative waiting period; (3) efficacy evaluation and adverse effects of nCRT; (4) surgical and recovery situations. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the t test. Measurement date with skewed distribution were represented as M ( P25, P75) or M (range), and comparison between groups was conducted using the Mann-Whitney U test. Count data were represented as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test or Fisher exact probability. Comparison of ordinal data was conducted using the non-parameter rank sum test. Repeated measurement data were analyzed using the repeated ANOVA. Results:(1) Grouping situations of the enrolled patients: a total of 90 patients were selected for eligibility. There were 77 males and 13 females, aged from 26 to 74 years, with a median age of 62 years. Of 90 patients, there were 45 cases in the experimental group and 45 cases in the control group. (2) Changing situations of nutritional status and quality of life of patients in nCRT and preoperative waiting period: ① during the nCRT treatment (week 3, week 6) and the preoperative waiting period (week 9, week 12, week 15), the body mass was (67±10)kg, (66±9)kg, (67±10)kg, (68±10)kg, (70±10)kg for the experi-mental group, respectively, and (65±9)kg, (59±8)kg, (62±8)kg, (64±8)kg, (66±9)kg for the control group. The multivariate test was conducted based on the mauchly's test of sphericity for the body mass ( χ2=195.010, P<0.05). There were significant differences in the time effect, interaction effect, intervention effect of body mass changing between the two groups ( F=93.974, 60.638, 4.144, P<0.05). ② During the nCRT treatment (week 3, week 6) and the preoperative waiting period (week 9, week 12, week 15), the total protein was (66±4)g/L, (65±4)g/L, (65±4)g/L, (68±4)g/L, (71±5)g/L for the experimental group, respectively, and (65±4)g/L, (62±5)g/L, (63±5)g/L, (65±5)g/L, (67±6)g/L for the control group. The multivariate test was conducted based on the mauchly's test of sphericity for the total protein ( χ2=652.524, P<0.05). There were significant differences in the time effect, interaction effect, interven-tion effect of total protein changing between the two groups ( F=672.507, 6.424, 5.057, P<0.05). ③ During the nCRT treatment (week 3, week 6) and the preoperative waiting period (week 9, week 12, week 15), the albumin was (40±3)g/L, (38±4)g/L, (38±4)g/L, (39±4)g/L, (40±4)g/L for the experimental group, respectively, and (39±4)g/L, (35±5)g/L, (36±4)g/L, (36±4)g/L, (37±5)g/L for the control group. The multivariate test was conducted based on the mauchly's test of sphericity for the albumin ( χ2=289.324, P<0.05). There were significant differences in the time effect, interaction effect, intervention effect of albumin changing between the two groups ( F=4 210.683, 5.013, 7.330, P<0.05). ④ During the nCRT treatment (week 3, week 6) and the preoperative waiting period (week 9, week 12, week 15), the prealbumin was (228±41)mg/L, (222±56)mg/L, (223±47)mg/L, (227±46)mg/L, (233±53)mg/L for the experimental group, respectively, and (202±49)mg/L, (174±68)mg/L, (179±54)mg/L, (185±51)mg/L, (193±57)mg/L for the control group. The multi-variate test was conducted based on the mauchly's test of sphericity for the prealbumin ( χ2=297.324, P<0.05). There were significant differences in the time effect, interaction effect, intervention effect of prealbumin changing between the two groups ( F=871.545, 6.111, 14.426, P<0.05). ⑤ During the nCRT treatment (week 3, week 6) and the preoperative waiting period (week 9, week 12, week 15), the hemoglobin was (124±14)g/L, (121±14)g/L, (125±13)g/L, (127±13)g/L, (128±13)g/L for the experimental group, respectively, and (121±18)g/L, (114±14)g/L, (116±14)g/L, (117±16)g/L, (118±22)g/L for the control group. The multivariate test was conducted based on the mauchly's test of sphericity for the hemoglobin ( χ2=257.560, P<0.05). There were significant differences in the time effect, interaction effect, intervention effect of hemoglobin changing between the two groups ( F=2 533.553, 4.142, 4.985, P<0.05). ⑥ During the nCRT treatment (week 3, week 6) and the preopera-tive waiting period (week 9, week 12, week 15), the patient-generated subjective global assessment (PG-SGA) score was 4.4±1.2,6.3±1.4, 5.5±1.4, 4.3±1.4, 3.4±1.7 for the experimental group, respec-tively, and 4.9±1.2, 7.4±1.7, 7.3±1.6, 6.3±1.4, 6.0±1.5 for the control group. The multivariate test was conducted based on the mauchly's test of sphericity for the PG-SGA score ( χ2=289.543, P<0.05). There were significant differences in the time effect, interaction effect, intervention effect of PG-SGA score changing between the two groups ( F=648.583, 41.906, 26.098, P<0.05). ⑦ During the nCRT treatment (week 3, week 6) and the preoperative waiting period (week 9, week 12, week 15), the quality of life questionnaire of stomach (QLQ-ST022) score was 13±3, 16±6, 16±4, 14±4, 12±5 for the experimental group, respectively, and 15±4, 21±6, 20±4, 17±4, 15±5 for the control group. The multivariate test was conducted based on the mauchly's test of sphericity for the QLQ-STO22 ( χ2=279.865, P<0.05). There were significant differences in the time effect, interaction effect, interven-tion effect of QLQ-STO22 changing between the two groups ( F=710.238, 7.261, 16.794, P<0.05). (3) Efficacy evaluation and adverse effects of nCRT: there were 25 patients and 20 cases of the experimental group with partial response and stable disease, showing the objective response rate and disease control rate as 55.6%(25/45)and 100.0%(45/45). There were 18 patients and 27 cases of the control group with partial response and stable disease, showing the objective response rate and disease control rate as 40.0%(18/45)and 100.0%(45/45). There was no significant difference in the nCRT efficacy between the two groups ( P>0.05). Cases with leukopenia, neutropenia, anemia, nausea, and loss of appetite were 27, 25, 19, 30, 34 for the experimental group, versus 37, 34, 29, 39, 42 for the control group, showing significant differences between the two groups ( χ2=5.409, 3.986, 4.464, 5.031, 5.414, P<0.05). (4) Surgical and recovery situations: patients of the experimental group underwent surgeries successfully. Two patients of the control group diagnosed with peritoneal metastasis after laparoscopic exploration underwent conversion therapy and no surgery, the other 43 patients underwent surgeries. The time to postoperative gastric tube removal, time to postopera-tive drainage tube removal, time to postoperative first flatus, time to postoperative first defecation, duration of postoperative hospital stay were 2.0 days (1.5 days, 3.0 days), 6.0 days (5.0 days,11.0 days), 2.0 days (1.5 days, 2.5 days), 2.0 days (1.5 days, 2.5 days), 7.0 days (6.0 days,14.0 days) for the experimental group, versus 3.0 days (2.0 days,4.0 days), 7.0 days (5.5 days,14.0 days), 2.0 days (1.5 days,3.0 days), 3.0 days (2.0 days,3.5 days), 8.0 days (6.0 days, 17.0 days) for the control group, showing significant differences between the two groups ( Z=-3.477, -4.398, -3.068, -5.786, -3.395, P<0.05). Conclusion:For AEG patients undergoing nCRT, the individualized full-course nutrition intervention involving nutritionists is beneficial to improve the nutritional status, reduce adverse reactions, and improve the quality of life of the patients, promote postoperative short-term recovery. Registry: this study was registered at clinicaltrials.gov in United States, with the registry number of NCT01962246.