The ontogeny of serum immunoreactive pancreatic lipase and cationic trypsinogen in the premature human infant

We evaluated the development of the exocrine pancreas in 16 healthy preterm infants (29.3 +/- 1.6 weeks). The infants were fed breast milk with formula supplements (n = 8) or formula alone (n = 8). Growth was monitored weekly for 12 weeks then at 3, 6, 9, 12 months. At the same intervals sera were determined for pancreatic lipase and cationic trypsinogen. In addition, cord blood samples were analysed from another 33 preterm (27.6 +/- 5.2 weeks) and 75 healthy full-term infants. Serum pancreatic lipase in the cord blood of term (3.7 +/- 0.4 micrograms/l) and preterm infants (1.8 +/- 0.2 micrograms/l) was significantly below values reported for older children (10.5 +/- 0.9 micrograms/l; p less than 0.001). In the preterm infant, serum lipase was also significantly lower than values obtained at term (p less than 0.001). At birth, serum trypsinogen for preterm (16.8 +/- 1.3 micrograms/l) and term infants (23.3 +/- 1.9 micrograms/l) were below those for older children (31.4 +/- 3.7 micrograms/l; p less than 0.05). Over the first 3 weeks of life, serum lipase and trypsinogen increased significantly. From 3 weeks to 12 months of age, serum trypsinogen values remained unchanged, but serum lipase increased dramatically after 10 weeks of age. Thus, at 6 and 12 months of age, the preterm infants had significantly higher serum lipase values than infants of the same age born at term. These two pancreatic enzymes appear to show independent age-related maturation in infants born before term. The rate of maturation of lipase appears to be accelerated by exposure to the extrauterine environment.     

Plasma 1.25-dihydroxyvitamin D concentrations in preterm infants

1.25-Dihydroxyvitamin D concentrations were measured in 10 preterm infants (mean gestational age 29 weeks, range 26-32; mean birthweight 1226 g, range 980-1700). Total parenteral nutrition was begun after birth and partial enteral feeding was started at 1 week of age. Total enteral feeding was achieved at a mean age of 26 days (range 16-47). The daily vitamin D3 intake was about 400 I. U. No clinical, chemical or radiological signs of rickets were observed. The mean 1.25-dihydroxyvitamin D concentration +/- SEM was 103.2 +/- 24.0 pmol/l at 1 week (range 9.6-252.0), 141.6 +/- 26.4 at 3 weeks (range 31.2-324.0), 153.6 +/- 21.6 at 6 weeks (range 67.2- 256.8), 165.6 +/- 24.0 at 9 weeks (range 74.4-307.2) and 153.6 +/- 21.6 at 12 weeks (range 76.8-268.8) postnatal age. The mean values at 6, 9 and 12 weeks were significantly higher (p resp. less than 0.01, less than 0.002 and less than 0.005) than in adults (88.8 +/- 7.2; n = 27). 1.25-Dihydroxyvitamin D concentrations were highly variable and did not correlate with 25-hydroxyvitamin D concentrations, plasma calcium and phosphorus concentrations and plasma alkaline phosphatase levels, nor with illness nor postnatal age. The data demonstrate that preterm infants are capable of producing high plasma levels of 1.25-dihydroxyvitamin D.     

High total and free 1,25-dihydroxyvitamin D concentrations in serum of premature infants

We investigated the relationship between serum total and free 1,25-dihydroxyvitamin D (1,25-OH2D) and the biochemical regulation of 1,25-OH2D production in premature infants. We measured 1,25-OH2D, vitamin D binding protein and related biochemical parameters and calculated the free 1,25-OH2D index in serum of 17 premature infants (birthweight 810-1700 g; gestational age 31-36 weeks) on two different occasions defined by body weight (Study A: 1,750-1,850 g, Study B: 2,100-2,200 g). Dietary calcium (Ca) intake was 1,5 or 2,6 mmol/kg/d, phosphorus (P) intake 1,7 mmol/kg/d and vitamin D intake 1,000 IU/d. Biochemical results were similar in infants with different Ca intakes and all were within reference ranges. Concentrations of vitamin D binding protein (Study A 0.15 +/- 0.03 g/l, Study B 0.14 +/- 0.03 g/l; means +/- SD) were lower, concentrations of 1,25 (OH)2D (Study A 180 +/- 67 pmol/l, Study B 216 +/- 53 pmol/l) were higher, and consequently the free 1,25-OH2D index (Study A 6.6 +/- 2.7, Study B 8.8 +/- 2.6) was 4 to 6 times higher than in previously studied term infants. 1,25-OH2D and the free 1,25-OH2D index increased significantly with age and were not correlated with serum P or parathyroid hormone. The data indicate that in premature infants with normal biochemical parameters of Ca and P metabolism elevated concentrations of 1,25-OH2D signify an increased fraction of free 1,25-OH2D and that increased production of 1,25-OH2D is not due to hypophosphatemia or hyperparathyroidism.     

Smoking during pregnancy--effects on the fetal thyroid function

Infants delivered at term by mothers smoking at least 10 cigarettes daily during pregnancy (n = 46) were found to be growth retarded compared to infants of non-smoking mothers (n = 49), birthweights 3,445 +/- 385 (SD) g and 3,667 +/- 392 g respectively (p less than 0.05) in the two groups. Cord serum thyrotropin (TSH) was significantly decreased (8.2 +/- 4.0 U/l vs. 10.3 +/- 4.9 U/l) and free thyroxine index (FT4I)/TSH ratio significantly increased (18.8 +/- 9.0 vs. 14.4 +/- 7.6) (p less than 0.05) in the smoking group compared to infants of non-smokers. Cord serum thyroxine (T4) and FT4I were higher in the smoking group (149.0 +/- 22.4 nmol/l and 125.5 +/- 14.9 respectively) compared to infants of non-smoking mothers (140.6 +/- 21.6 nmol/l and 120.0 +/- 16.5 respectively), with borderline statistical significance (0.05 less than p less than 0.10). The results indicate that infants of smoking mothers may have a hyperfunction of the thyroid gland at birth compared to infants of non-smokers, with a negative feed-back on TSH production from the pituitary gland. Increased metabolic rate and oxygen consumption caused by fetal thyroid hyperfunction may be pathogenetic factors for the fetal growth retardation caused by maternal smoking.     

Vitamin A status in full-term and premature infants

Vitamin A status has been assessed by studying plasma vitamin A and retinol binding protein (RBP) levels in premature infants receiving 7,500 IU vitamin A/d (RDA 660-3,300 IU/d) and in control term babies during the 3 first months of life. Sampling was performed within the first week (D0-D7), between the 8th and the 30th day (D8-D30) and during the 2nd and the 3rd month of life (M2-M3). At D0-D7, vitamin A levels of the PTI group (28-32 weeks gestational age), PTII (33-36 weeks GA) and AT (control term newborn) were 242.1 +/- 20.5 (X +/- SEM), 176.1 +/- 12.3 and 213.1 +/- 17.1 micrograms/l respectively (P = 0.005). At D8-D30, these values were 264.2 +/- 26.0, 270.4 +/- 21.6 and 242.6 +/- 24.5 micrograms/l respectively (NS), and at M2-M3 234.2 +/- 21.6, 282.1 +/- 18.5 and 292.1 +/- 31.5 micrograms/l (NS). A significant difference was found between the values of the different dosage periods for PTII and AT groups; no difference in RBP levels was found either between groups or between dosage periods. At birth, our results show that the RBP synthesis is not closely linked to gestational age. The plasma vitamin A levels which rely on foetal stores and therefore on transplacental passage and on peripheral tissue requirements are low at 33-36 weeks gestational age. With a 7,500 IU daily supplement, excessively high vitamin A levels were not observed in premature infants; vitamin A and RBP levels in premature infants receiving supplement are not different from controls despite the 8-12-week term high vitamin A supply.     

Intestinal absorption of vitamin E in low birth weight infants

Intestinal absorption of dl-alpha-tocopheryl acetate was studied in low birth weight infants. Vitamin E was given from the first day of life, either as a water-soluble (Ephynal) or as a lipid-soluble preparation (E-vitamin). Serum-alpha-tocopherol concentrations were determined before treatment and on days three and seven. Treatment with both vitamin E preparations increased serum-alpha-tocopherol on day three and seven. The mean serum-alpha-tocopherol +/- SD on day seven were 41.4 +/- 10.7 mumol/l for the Ephynal group and 26.7 +/- 12.5 mumol/l for the E-vitamin group, this difference being statistically significant (p less than 0.025). Oral feeding seems to influence the absorption of tocopherol from E-vitamin, as the infants with the highest serum-alpha-tocopherol concentrations were those with the highest oral/total feeding ratios. In infants with birth weight less than 1 000 g treatment with 25 mg Ephynal/day was found to increase serum-alpha-tocopherol on day seven to 46.9 +/- 12.3 mumol/l (mean +/- SD). This concentration is comparable to those reported by others using higher doses of oral vitamin E.     

Iron status of the preterm infant during the first year of life

The iron status of 49 preterm infants (mean gestational age 33.1 weeks) was assessed serially during the 1st year of life. Haemoglobin concentration, serum ferritin, serum transferrin, serum iron, and transferrin saturation were measured on nine occasions in each infant. In 16 infants of gestational age 28-32 weeks the haemoglobin concentration was significantly lower at 3, 6, and 9 weeks when compared to 33 infants of gestational age 33-36 weeks. For all other measures of iron status there were no significant differences between these gestational age groups. For the entire group of 49 infants the mean haemoglobin concentration reached a nadir of 11.2 g/dl at 9 weeks. Mean serum iron and transferrin saturation reached peaks of 24 mumol/l and 65%, respectively, at 3 weeks. The mean serum ferritin remained over 100 micrograms/l until after 18 weeks. 13 infants (26%) had iron deficiency defined as either serum ferritin less than 10 micrograms/1 (n = 10) or transferrin saturation less than 10% (n = 5) or both (n = 3).     

Mineral homeostasis in very premature infants: serial evaluation of serum 25-hydroxyvitamin D, serum minerals, and bone mineralization

This study was designed to evaluate the role of vitamin D sufficiency, as reflected in serum 25-hydroxyvitamin D (25-OHD) concentrations, on serum minerals and bone mineralization in very premature infants. Seventy-two infants (mean +/- SD gestation 30.1 +/- 2.5 weeks, mean +/- SD birth weight 1178 +/- 278 gm) were observed serially for the first 3 months of life. Mean serum calcium and phosphorus values, but not magnesium, remained low prior to 12 weeks. The percentage of infants with moderate to severe hypomineralization was 75% at 3 weeks, 55% at 6 weeks, 54% at 9 weeks, and 15% at twelve weeks. Low serum calcium and phosphorus values, high alkaline phosphatase activity, and moderate-severe hypomineralization were more frequent in infants weighing less than 1000 gm and in those with lower mineral intake. With a 400 IU vitamin D supplement, 45% of infants could maintain an initially normal serum 25-OHD concentration or increase low concentrations, whereas 55% had falling or persistently low (less than or equal to 15 ng/ml) 25-OHD concentrations. Birth weight and mineral intakes were comparable in these two groups, yet the group with the lower serum 25-OHD concentration had lower serum calcium and higher alkaline phosphatase values, and a higher percentage of moderate to severe hypomineralization. Regardless of birth weight, mineral intake, or 25-OHD concentration, increases in serum calcium and phosphorus values and in mineralization were seen at postconception term (12 weeks in most infants, nine weeks in those weighing 1250 to 1600 gm). At 12 weeks of age, but not before, serum 25-OHD concentration was directly correlated with serum calcium (r = 0.47, P less than 0.01) and serum phosphorus (r = 0.47, P less than 0.01) and inversely correlated with alkaline phosphatase values (r = -0.71, P less than 0.01). Mineral availability and 25-OHD sufficiency both appear to be important and to act synergistically, with neither totally compensating for the other.     

Vitamin D nutritional status of premature infants supplemented with 500 IU vitamin D2 per day

The vitamin D nutritional status of premature infants was assessed by determining plasma 25-hydroxyvitamin D concentrations before and during supplementation with 500 IU vitamin D2 per day. Fifty-one samples were collected from 25 healthy infants fed breast milk and a vitamin D3 fortified formula. Gestational age was 32.2 +/- 2.4 weeks (mean +/- 1 SD). 25-hydroxyvitamin D levels before supplementation correlated well with maternal values (r = 0.81). The infants' mean plasma concentration increased from 30.6 +/- 13.7 nmol/l (mean +/- 1 SD) after birth to 46.3 +/- 10.5 nmol/l after 9 +/- 1 days (p less than 0.0025), and to 65.3 +/- 16.6 nmol/l after 37 +/- 10 days of vitamin D2 treatment (p less than 0.0005). 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3 were determined separately, and it appeared that the rise was accounted for by the D2 fraction while 25-hydroxyvitamin D3 concentrations were unchanged. The results demonstrate that vitamin D2 is well absorbed and hydroxylated in the 25 position by premature infants free of associated disease, and that a supplementation of 500 IU per day in addition to breast milk and a regular vitamin D fortified formula is adequate to rapidly establish 25-hydroxyvitamin D levels within the normal adult range.     

Serum vitamin D metabolites in very low birth weight infants with and without rickets and fractures

Seventy-one very low birth weight (less than or equal to 1500 gm) infants were studied to determine the sequential changes in serum vitamin D metabolite concentrations between infants with and without radiographically documented rickets, fractures, or both (R/F). Usual intake of vitamin D included 20 IU/kg/day from parenteral nutrition or 400 IU/day supplementation with enteral feeding. Radiographs of both forearms and serum samples were obtained at 3, 6, 9, and 12 months. Twenty-two infants had R/F. At 3 months, significantly lower mean (+/- SEM) serum phosphorus levels (4.5 +/- 0.4 vs 6.1 +/- 0.2 mg/dl), higher 1,25-dihydroxyvitamin D (1,25-[OH]2D) concentrations (96 +/- 5 vs 77 +/- 4 pg/ml), and higher free 1,25-(OH)2D index (1,25-[OH]2D:vitamin D binding protein ratio; 5.2 +/- 0.3 x 10(5) vs 4.0 +/- 0.2 x 10(5] were found in the R/F group. These values returned to normal and were similar between groups on subsequent measurements. Serum calcium, magnesium, and 25-hydroxyvitamin D (25-OHD) concentrations were normal and similar between groups. In both groups, serum vitamin D binding concentrations increased initially but remained stable and normal beyond 6 months. We conclude that in very low birth weight infants with R/F, the vitamin D status (as indicated by serum 25-OHD concentrations) is normal, and that lowered serum phosphorus levels, higher serum 1,25-(OH)2D levels, and a higher free 1,25-(OH)2D index support the thesis that mineral deficiency (especially of phosphorus) may be important in the pathogenesis of R/F in small preterm infants.     

Effect of season and vitamin D supplementation on plasma concentrations of 25-hydroxyvitamin D in Norwegian infants

Plasma concentrations of 25-hydroxyvitamin D (25OHD) were determined in 81 vitamin D supplemented or unsupplemented infants at the end of winter. The values were compared with maternal levels and with concentrations found in 22 unsupplemented infants at the end of summer. The 25OHD levels of the neonates were lower, but closely related to maternal values (r = 0.95, p less than 0.0005). Unsupplemented breast-fed infants had lower 25OHD levels at 6 weeks than at 4 days (16 +/- 7 vs. 32 +/- 15 nmol/l, mean +/- 1 SD, p less than 0.0005). The mean 25OHD level of vitamin D supplemented 6-12 months old infants was intermediate between those of the unsupplemented nursed groups and the unsupplemented children studied during summer (53 +/- 28 vs. 85 +/- 28 nmol/l, p less than 0.0005). Six weeks old infants who had received a milk formula containing 400 IU vitamin D3 per liter had levels similar to the latter group (92 +/- 21 nmol/l). The data suggest that the vitamin D stores acquired during fetal life, or from ultraviolet light exposure during the summer, may be inadequate to maintain safe levels of 25OHD throughout the winter, but that a daily supplement of 400 IU is adequate to establish concentrations in the summer range.     

Parenteral nutrition for infants: effect of high versus low calcium and phosphorus content

Calcium (Ca) and phosphorus (P) homeostasis were determined in 18 infants (birth weight, 2,810 +/- 135 g; gestational age, 37.4 +/- 0.5 weeks; mean +/- SEM) who received high or low Ca and P content (Ca, P) parenteral nutrition (PN) with a fixed, low dose of vitamin D (25 IU/dl). Nine infants were randomized into low (standard) Ca, P (20 mg Ca and 15.5 mg P/dl) and nine into high Ca, P (60-80 mg Ca and 46.5-62 mg P/dl) PN, and then were studied for up to 6 weeks. The high Ca, P group had stable serum 1,25 dihydroxyvitamin D [1,25(OH)2D], which consistently remained within the normal range (less than 116 pg/ml). Tubular reabsorption of phosphorus (TRP) also was stable and remained consistently less than 90%. The low Ca, P group had elevated and higher 1,25(OH)2D (p = 0.03) than the high Ca, P group. The mean serum 1,25(OH)2D concentration rose from 32 to 112, 115, and 133 pg/ml over a period of 6 weeks. TRP also was higher (p = 0.02) and remained consistently greater than 90%. There were no significant differences between groups in serum parathyroid hormone, calcitonin, Ca, Mg, P, alkaline phosphatase, vitamin D binding protein, and 25 hydroxyvitamin D concentrations; urine Ca/creatinine and Mg/creatinine ratios, and fractional excretion of sodium (Na). Thus, a "high" Ca (60 mg/dl) and P (46.5 mg/dl) content in PN solutions can result in stable serum 1,25(OH)2D and TRP, presumably reflecting minimal stress to Ca and P homeostatic mechanisms without further increase in urinary Ca excretion.     

Enteral erythropoietin increases plasma erythropoietin level in preterm infants: a randomized controlled trial

OBJECTIVE: To evaluate the effects of enteral administration of recombinant human erythropoietin (rhEPO) on serum level of erythropoietin and erythropoiesis in preterm infants. STUDY DESIGN: Randomized controlled trial. SETTING: Level III NICU. SUBJECTS: 16 preterm infants less than 34 wk with birth weight less than 1800 g. INTERVENTION: Enteral rhEPO 400 U/kg, three times/week, plus FeSO4,3-6 mg/Kg/day ( Study group, n = 7) or FeSO4 only (Control group, n = 9). OUTCOME MEASURES: Hemoglobin, serum erythropoietin (EPO), reticulocyte count, and serum ferritin levels, measured at baseline, after 10 days and at discharge. RESULTS: Mean birth weight and gestational age for the Study and the Control groups were 1328.5 +/- 267.4 vs. 1392.8 +/- 196.7 g and 30.7 +/- 2.5 vs. 30.2 +/- 0.9 weeks, respectively. At discharge, there was no difference in hemoglobin or hematocrit but the reticulocyte counts were significantly higher in the Study group (1.4 +/- 0.7 vs. 0.7 +/- 0.4, P = 0.03). Serum erythropoietin level was significantly higher in the Study group (18 +/- 11 vs. 8.6 +/- 3.9 mU/mL, P = 0.006). Conversely, serum ferritin level was lower in the study group but did not achieve statistical significance. CONCLUSIONS: Enteral administration of rhEPO in preterm infants resulted in increase in serum erythropoietin and reticulocyte counts at the time of discharge without significantly affecting hemoglobin or hematocrit.     

早产儿出生时25羟基维生素D水平与呼吸窘迫综合征关系分析

目的研究早产儿出生时血清25羟基维生素D[25(OH)D]水平与呼吸窘迫综合征(RDS)的关系。方法将2014年1月至2016年12月于新生儿病房住院的符合入组标准和排除标准的早产儿112例分为RDS组(n=72)和对照组(n=40)。收集两组患儿的一般临床资料,包括胎龄、出生体重、性别、分娩方式、1 min及5 min Apgar评分,以及母妊娠期糖尿病和产前激素使用情况。采集患儿的外周静脉血,分离血清,采用化学发光免疫分析法检测血清25(OH)D水平;采用二元logistic回归模型分析25(OH)D水平与RDS发生的关系。结果 RDS组1 min及5 min Apgar评分、血清25(OH)D水平显著低于对照组(P0.05),新生儿窒息及维生素D缺乏发生率显著高于对照组(P0.05)。经二元logistic回归分析结果显示,新生儿窒息(OR=2.633,95%CI:1.139~6.085)、维生素D缺乏(OR=4.064,95%CI:1.625~10.165)是导致早产儿RDS发生的危险因素(P0.05)。结论早产儿出生时维生素D缺乏可能与RDS发病风险增加有关,母孕期合理补充维生素D可能降低早产儿RDS发病率。     

Serum vitamin A levels in mothers and their breast-fed term infants with or without supplemental vitamin A

Serum concentrations of vitamin A were measured in term infants (n = 72) and their mothers at delivery and after 20 weeks of breast-feeding (n = 48). During the 20 weeks the infants received either no supplemental vitamin A (but the mothers were given 3,000 IU vitamin A daily) (n = 16) or a daily vitamin A supplementation of 600 (n = 17) or 1,500 IU (n = 15). After 20 weeks of breast-feeding the vitamin A levels in the unsupplemented infants were similar to those at birth. The infants supplemented either with 600 or 1,500 IU had higher vitamin A serum levels than at birth (p less than 0.01), however, there was no difference between the two supplemented groups. During lactation, the serum vitamin A concentrations of the mothers increased significantly in all groups with or without vitamin A supplementation.     

VITAMIN D METABOLISM IN PRETERM INFANTS

ABSTRACT. In order to evaluate after birth the changes in circulating vitamin D metabolite levels in preterm babies supplemented with vitamin D (2100 I. U./d), the serum concentration of 25-hydroxyvitamin D [25-OHD] and 1 α,25-dihydroxy vitamin D [1, 25(OH)₂D] were measured in 22 infants (31 to 35 weeks of gestation) from birth up to 96 hours of age. Compared to cord blood levels, serum calcium decreased significantly during the first 24 hours of life ( p <0.005) and remained low until day 4. Serum immunoreactive parathyroid hormone (iPTH) levels increased from birth to 24 hours and then plateaued. The 25-OHD levels at birth were 27.5±2.5 nmol/l and increased to 67.5±12.5 nmol/l ( p <0.005) during the four days of the study. During the same period, the 1, 25(OH)₂D serum levels increased steadily from 84<7 to 343<105 pmol/l ( p <0.005). At all times, there was a positive correlation between 25-OHD levels and those of 1, 25(OH)₂D. Our data demonstrate that in preterm infants after 31 weeks of gestation, absorption and activation of vitamin D is present as soon as 24 hours after birth and that early neonatal hypocalcemia is unlikely to be caused by an impairment of either PTH secretion or vitamin D activation.     

Absorption, dosage, and effect on mineral homeostasis of 25-hydroxycholecalciferol in premature infants: comparison with 400 and 800 IU vitamin D2 supplementation

Because the efficiency of vitamin D absorption or hepatic uptake and 25-hydroxylation appears decreased in very premature infants, the routine use of 25-hydroxycholecalciferol (25-OHD3) supplementation has been suggested. Absorption studies of a 3 micrograms/kg orally administered dose of 25-OHD3 showed peak serum 25-hydroxyvitamin D2 and -vitamin D3 (25-OHD) concentrations at 4 to 8 hours similar in timing but of lesser magnitude to those seen in adults. Administration of 1 microgram/kg birth weight/day of 25-OHD3 corrected moderately low, but not very low serum (25-OHD) concentrations, and 2 micrograms/kg BW/day resulted in rapid and sustained increase in serum 25-OHD. Administration of 800 IU ergocalciferol (D2) also produced significantly higher serum 25-OHD concentrations than those in infants given 400 IU vitamin D2, but increases in serum 25-OHD were more gradual than in infants given 25-OHD3. In treatment trials with infants weighing less than 1500 gm, those given 800 IU D2, compared with those given 400 IU D2, had higher serum calcium concentrations and less frequent moderate or severe hypomineralization. Infants given 2 micrograms/kg BW 25-OHD3 had a significant increase in serum phosphorus values, but a decrease in serum calcium and magnesium concentrations, and parathyroid hormone also was suppressed to low normal values. The frequency of moderate to severe hypomineralization remained the same as in infants given 400 IU D2. In a subgroup of infants, serum 1,25-dihydroxyvitamin D was elevated over adult values, both in infants given 25-OHD3 (68.5 +/- 8.4 pg/ml) and in infants given vitamin D2 (60 +/- 6.7 pg/ml). Serum vitamin D concentrations were undetectable in four of six infants receiving 25-OHD3, but were elevated (5 to 31 ng/ml) in four infants receiving vitamin D2. Although 800 to 1000 IU D2 can be recommended as routine vitamin D supplementation in very premature infants fed standard formula, the use of 25-OHD3 requires further study.     

Evaluation of a pediatric multiple vitamin preparation for total parenteral nutrition. II. Blood levels of vitamins A, D, and E

This study represents the first attempt to evaluate the American Medical Association Nutrition Advisory Group (NAG) recommendations for intravenous vitamin A, D, and E dosages for infants and children. Patients studied included 18 preterm infants (group 1) and 26 term infants and children (group 2A) receiving total parenteral nutrition for 2 to 4 weeks and eight infants and children receiving total parenteral nutrition for 3 to 6 months (group 2B). Term gestation infants and children up to 11 years of age all received the same dosages (those that were recommended by the NAG for children weighing more than 10 kg). Preterm infants received 65% of these doses. In group 1, cord blood alpha-tocopherol levels were less than 0.22 mg/dL in seven preterm infants (reference value = 0.29 +/- 0.04), but mean levels increased to 1.65 +/- 0.17 mg/dL after four days of treatment. Eight infants consistently received additional vitamin E orally (80 to 150 mg daily), and their levels increased to 2.18 +/- 0.26 mg/dL by four days of study and to 3.49 +/- 0.57 mg/dL after 3 weeks. Oral supplementation in the preterm infants appeared to be unnecessary because intravenous vitamins alone maintained levels above 1.1 mg/dL. In group 2, alpha-tocopherol levels were maintained within the reference range. Patients receiving lipid emulsions containing substantial quantities of alpha-tocopherol had significantly higher blood levels than patients receiving lipid emulsions containing little alpha-tocopherol (P less than .01). Mean 25-OH vitamin D levels were maintained above or within the reference range in groups 2A and 2B.(ABSTRACT TRUNCATED AT 250 WORDS)     

Serum Vitamin A Levels in Mothers and Their Breast-Fed Term Infants with or without Supplemental Vitamin A

ABSTRACT. Serum concentrations of vitamin A were measured in term infants ( n =72) and their mothers at delivery and after 20 weeks of breast-feeding ( n =48). During the 20 weeks the infants received either no supplemental vitamin A (but the mothers were given 3000 IU vitamin A daily) ( n =16) or a daily vitamin A supplementation of 600 ( n =17) or 1500 IU ( n =15). After 20 weeks of breast-feeding the vitamin A levels in the unsupplemented infants were similar to those at birth. The infants supplemented either with 600 or 1500 IU had higher vitamin A serum levels than at birth ( p <0.01), however, there was no difference between the two supplemented groups. During lactation, the serum vitamin A concentrations of the mothers increased significantly in all groups with or without vitamin A supplementation.     

早产儿出生时血清25-羟维生素D水平与支气管肺发育不良的相关性

目的分析早产儿出生时血清25-羟维生素D[25(OH)D]水平与支气管肺发育不良(BPD)的关系。方法选取2014年1月至2016年12月入住NICU、出生胎龄34周的早产儿,按是否患BPD分为BPD组(41例)和对照组(219例),分析25(OH)D水平与BPD的关系。结果 BPD组血清25(OH)D水平显著低于对照组(37±17 nmol/L vs 47±20 nmol/L;P0.05);维生素D缺乏率显著高于对照组(90.2%vs 74.0%,P0.05)。血清25(OH)D水平与BPD发生率呈负相关(r=-0.201,P=0.001)。结论早产儿维生素D缺乏可能与BPD发病有关,但需多因素分析进一步证实。