human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: ABSTRACT : We prospect ively assessed and compared the vitamin A status of two groups of preterm neonates ( < 1500 g birth weight , < 32 wk gestation ) , one who developed clinical and radiographic evidence of bronchopulmonary dysplasia ( BPD ) ( n = 10 ) , and the other ( control ) who developed no significant lung disease ( n = 8) . The infants with BPD in this study required prolonged mechanical ventilation and supplemental O2 therapy , and had a higher incidence of cardiorespiratory complications when compared to controls . Their mean plasma vitamin A concentrations were significantly lower than those of controls at four sampling times in the 1st postnatal month . In contrast to the controls , infants with BPD showed a substantial decline in their plasma vitamin A concentrations from the initial values , and a high percentage of individual values of plasma vitamin A concentration in these infants were < 10 μg/dl during the 8-wk postnatal period of observation . Delayed establishment of gastrointestinal feeding and a lower vitamin A intake in these infants relative to controls may have accounted for this decline . Our data show that preterm neonates who develop BPD  have suboptimal plasma vitamin A concentrations for extended periods of time postnatally . We speculate that the necrotizing bronchiolitis and squamous metaplasia of conducting airways associated with vitamin A deficiency could influence the orderly repair of lung injury in susceptible neonates who are mechanically ventilated and could contribute to the pathophysiology of BPD in these infants . Further studies are needed to determine whether more efficient management of these neonates with regard to their vitamin A nutrition and early achievement of vitamin A sufficiency could result in a decrease in the incidence and severity of BPD BACKGROUND Intramuscular supplementation with vitamin A in large doses may reduce the incidence of chronic lung disease . AIM To investigate whether oral supplementation with vitamin A would reduce the incidence of chronic lung disease in a group of extremely low birthweight infants . METHODS Infants with birth weight < 1000 g were r and omised at birth to receive oral vitamin A supplementation ( 5000 IU/day ) or placebo for 28 days . The primary outcome was oxygen dependency at 28 days of age or death . RESULTS A total of 154 infants were r and omised ; 77 received vitamin A ( median birth weight ( interquartile range ) 806 ( 710–890 ) g ) , and 77 received placebo ( median birth weight ( interquartile range ) 782 ( 662–880 ) g ) . Plasma vitamin A concentrations in the supplemented group were significantly higher at 24 hours of age but did not differ significantly at birth , 12 hours of age , 7 days , or 28 days of life . There were no significant differences in the proportion of infants who survived , required oxygen at 28 days , required oxygen at 36 weeks postmenstrual age , survived without chronic lung disease at 36 weeks , survived without significant retinopathy , or who survived without significant intraventricular haemorrhage . CONCLUSIONS Oral supplementation with 5000 IU vitamin A in extremely low birthweight infants does not significantly alter the incidence of chronic lung disease . However , this dose may have been inadequate to achieve optimal serum retinol concentrations Formula-fed infants with birth weights < or = 1500 g ( n = 61 ) were stratified by 250-g birth-weight ranges and r and omly assigned to receive one of three preterm infant formulas ( vitamin A contents of 820 IU , 1640 IU , or 2900 IU/MJ ; 1 RE = 3.3 IU vitamin A activity ) when subjects tolerated 0.314 MJ.kg-1.d-1 . Experimental formula feedings were continued until infants weighed approximately 2 kg or until hospital discharge . Vitamin A status as indicated by serum retinol and retinol-binding protein ( RBP ) concentrations significantly decreased during experimental formula feeding at the lowest vitamin A intake . All subjects fed the formula providing the lowest vitamin A intake had hyporetinolemia ( < 0.70 mumol/L , or < 20 micrograms/dL ) , which occurred less frequently ( P < 0.05 ) with the intermediate ( 6 of 20 ) and the high ( 6 of 21 ) vitamin A intakes . Other outcome measures , including increases in weight , length , and head circumference , and ventilatory support and oxygen therapy , were not different among groups . After the end of the experimental formula-feeding period , all infants were fed st and ard infant formulas with a vitamin A content of 715 IU/MJ . In a subset of 19 of these infants , subsequent vitamin A status was monitored at ages 6 - 12 mo and was found to be comparable with that of older children and adults , regardless of the vitamin A content of the formula fed during hospitalization . ( ABSTRACT TRUNCATED AT 250 WORDS Preterm infants were r and omly assigned to receive routine vitamin A supplementation ( Regular A ) or additional vitamin A in intravenous lipids ( High A ) . Because infants with bronchopulmonary dysplasia ( BPD ) have poorer vitamin A status than infants who do not develop BPD , High A and Regular A infants were divided by BPD ( no or yes ) before determining the effects of treatment on intake and plasma concentration of retinol in the first month . Compared with infants without BPD , those with BPD received less retinol ( RE.kg-1.d-1 ) if assigned to Regular A and more if assigned to High A ( BPD by vitamin A interaction , P < 0.002 ) . High A-BPD infants compared with Regular A-BPD infants had significantly higher plasma retinol concentrations in the first month . Retinyl palmitate appears to be an effective adjunct to routine vitamin A administration . Infants most likely to benefit from receiving vitamin A in intravenous lipids are those advanced more slowly to full enteral feeding We conducted a r and omized , double-blind , controlled trial to determine whether vitamin A supplementation from early postnatal life could reduce the morbidity associated with bronchopulmonary dysplasia in very low birth weight ( VLBW ) neonates . Forty VLBW neonates ( 700 to 1300 g birth weight , 26 to 30 weeks gestational age ) , who were oxygen dependent and required mechanical ventilation for at least 72 hours after birth , were given by the intramuscular route either supplemental vitamin A ( retinyl palmitate 2000 IU ) or 0.9 % saline solution on postnatal day 4 and every other day thereafter for a total of 14 injections over 28 days . The study groups were comparable in gestational maturity , clinical characteristics , initial lung disease , and vitamin A status at entry into the trial . Vitamin A administration result ed in significantly higher mean plasma concentrations of vitamin A and retinol-binding protein in treated infants compared with controls . Bronchopulmonary dysplasia was diagnosed in nine of 20 infants given vitamin A supplement and in 17 of 20 control infants ( P less than 0.008 ) . Four of 19 infants in the vitamin A group and 11 of 20 in the control group required mechanical ventilation on study day 28 ( P less than 0.029 ) . The need for supplemental oxygen , mechanical ventilation , and intensive care was reduced in infants given vitamin A supplement compared with controls . Airway infection and retinopathy of prematurity were less frequent in the vitamin A group . We conclude that vitamin A supplementation at the dosage used in this trial in VLBW neonates not only improves their vitamin A status but also appears to promote regenerative healing from lung injury , as evidence d by a decrease in the morbidity associated with bronchopulmonary dysplasia OBJECTIVE Preterm infants show reduced retinal sensitivity at term corrected age compared with newborn term infants . We tested the hypothesis that retinal sensitivity in preterm infants is improved by early , high-dose vitamin A. STUDY DESIGN We report a double-blind , r and omized controlled trial of infants < 32 weeks ' gestation and /or < 1501 g birth weight . Supplemented infants received additional intramuscular vitamin A 10 000 IU 3 times weekly from day 2 for a minimum of 2 weeks or until establishment of oral feeding . Hepatic stores were assessed by relative dose response ( RDR ) . The primary outcome measure was cone-corrected dark-adapted retinal rod sensitivity measured by electroretinogram at 36 weeks ' postmenstrual age ( PMA ) . RESULTS Eighty-nine infants ( 42 supplemented and 47 controls ) were recruited .  Plasma retinol was higher in supplemented infants at 7 and 28 days ( median , 1.0 vs 0.5 μmol/L and 0.7 vs 0.6 μmol/L ; P < .001 and .03 , respectively ) . Neither plasma retinol nor RDR differed between groups at 36 weeks ' PMA . Retinal sensitivity was greater in supplemented infants ( -0.81 vs -0.61 log cd • s • m(-2 ) ; P < .03 ) and was not related to RDR . CONCLUSIONS Early high-dose intramuscular vitamin A supplementation for infants at risk of retinopathy of prematurity  improves retinal function at 36 weeks ' PMA The purpose of this trial was to test the hypothesis that vitamin A adequacy may decrease the incidence of  bronchopulmonary dysplasia ( BPD ) in very-low-birth-weight infants .  Serum vitamin A levels were measured and the effects of two regimens of vitamin A supplementation on the incidence of BPD were compared . There were 24 infants in each of two groups with a mean birth weight less than 1000 g , a mean gestational age of 27 weeks , and similar sexual and racial mixes . In group I ,  vitamin A levels  were measured after 1 week of parenteral nutrition and , if low , the infant was given a 2000-IU supplement intramuscularly three times a week , beginning on the 10th to 14th day of life . In group II , the same supplementation was begun on the second to fourth day of life . In both groups , when enteral feedings reached 60 kcal/kg per day , 2500 IU/d vitamin A was given orally . The incidence of oxygen support at 28 days was similar in both groups , although in group II there was a trend toward less vigorous ventilatory support . chi 2 analysis showed that a significantly smaller proportion of infants in group II had BPD at 36 weeks ' gestational age than in group I. Length of neonatal intensive care unit stay was significantly reduced from 81 to 60 days . We conclude that vitamin A supplementation should be administered early to small , premature infants who are at risk for BPD and that monitoring of plasma levels is essential We conducted a r and omized trial in very low birth weight neonates ( n = 51 ) to determine whether vitamin A supplementation by enteral administration would increase plasma vitamin A concentrations to the same degree as by intramuscular administration .  Mean plasma vitamin A concentrations were significantly higher in the intramuscular-administration group than in the enteral-administration group by postnatal day 7 ; this effect persisted throughout the remainder of the trial . At the dosage used in this trial , vitamin A supplementation by the enteral route is not as effective as that by the intramuscular route in very low birth weight neonates BACKGROUND Low-birth-weight ( LBW ) infants ( < 2,500 g ) are at increased risk of respiratory infection in the first few months of life and have low liver stores of vitamin A. As retinol is essential for respiratory epithelial cell differentiation , deficiency could result in pathological changes in the respiratory epithelium , with respiratory problems . OBJECTIVE A r and omised , double-blind , placebo-controlled trial to investigate the effect of vitamin A supplementation on the incidence and severity of respiratory infections in LBW infants during their first year of life . METHOD One hundred and thirty LBW infants ( gestational age < 36 weeks and birth weight 950 - 1,700 g ) were enrolled in the study . The infants were r and omly allocated to a vitamin A or placebo group . Infants in the vitamin A group received 25,000 IU of vitamin A ( retinyl palmitate , Arovit drops , Roche , Basle , Switzerl and ) on study days 1 , 4 and 8 . Study day 1 was between 36 and 60 hours after delivery . Infants in the placebo group received a placebo ( formulated by Roche ) with a similar appearance and packed in the same dropper bottles as the vitamin A drops . RESULTS Vitamin A supplementation markedly improved serum retinol levels . After the last vitamin A dose , the vitamin A group had higher mean serum retinol concentrations than the placebo group ( 45.77 + /- 17.07 micrograms/dl v. 12.88 + /- 6.48 micrograms/dl , P = 0.0001 ) . There was no evidence of improvement in neonatal or post-neonatal respiratory problems associated with vitamin A supplementation . Vitamin A and placebo groups did not differ in the occurrence or duration of respiratory distress or the need for head-box oxygen . There were also no significant differences in the cumulative probability of developing lower or upper respiratory tract infection through the first year of life . There was a slight suggestion 
    Output:
    
agent
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: ABSTRACT : We prospect ively assessed and compared the vitamin A status of two groups of preterm neonates ( < 1500 g birth weight , < 32 wk gestation ) , one who developed clinical and radiographic evidence of bronchopulmonary dysplasia ( BPD ) ( n = 10 ) , and the other ( control ) who developed no significant lung disease ( n = 8) . The infants with BPD in this study required prolonged mechanical ventilation and supplemental O2 therapy , and had a higher incidence of cardiorespiratory complications when compared to controls . Their mean plasma vitamin A concentrations were significantly lower than those of controls at four sampling times in the 1st postnatal month . In contrast to the controls , infants with BPD showed a substantial decline in their plasma vitamin A concentrations from the initial values , and a high percentage of individual values of plasma vitamin A concentration in these infants were < 10 μg/dl during the 8-wk postnatal period of observation . Delayed establishment of gastrointestinal feeding and a lower vitamin A intake in these infants relative to controls may have accounted for this decline . Our data show that preterm neonates who develop BPD  have suboptimal plasma vitamin A concentrations for extended periods of time postnatally . We speculate that the necrotizing bronchiolitis and squamous metaplasia of conducting airways associated with vitamin A deficiency could influence the orderly repair of lung injury in susceptible neonates who are mechanically ventilated and could contribute to the pathophysiology of BPD in these infants . Further studies are needed to determine whether more efficient management of these neonates with regard to their vitamin A nutrition and early achievement of vitamin A sufficiency could result in a decrease in the incidence and severity of BPD BACKGROUND Intramuscular supplementation with vitamin A in large doses may reduce the incidence of chronic lung disease . AIM To investigate whether oral supplementation with vitamin A would reduce the incidence of chronic lung disease in a group of extremely low birthweight infants . METHODS Infants with birth weight < 1000 g were r and omised at birth to receive oral vitamin A supplementation ( 5000 IU/day ) or placebo for 28 days . The primary outcome was oxygen dependency at 28 days of age or death . RESULTS A total of 154 infants were r and omised ; 77 received vitamin A ( median birth weight ( interquartile range ) 806 ( 710–890 ) g ) , and 77 received placebo ( median birth weight ( interquartile range ) 782 ( 662–880 ) g ) . Plasma vitamin A concentrations in the supplemented group were significantly higher at 24 hours of age but did not differ significantly at birth , 12 hours of age , 7 days , or 28 days of life . There were no significant differences in the proportion of infants who survived , required oxygen at 28 days , required oxygen at 36 weeks postmenstrual age , survived without chronic lung disease at 36 weeks , survived without significant retinopathy , or who survived without significant intraventricular haemorrhage . CONCLUSIONS Oral supplementation with 5000 IU vitamin A in extremely low birthweight infants does not significantly alter the incidence of chronic lung disease . However , this dose may have been inadequate to achieve optimal serum retinol concentrations Formula-fed infants with birth weights < or = 1500 g ( n = 61 ) were stratified by 250-g birth-weight ranges and r and omly assigned to receive one of three preterm infant formulas ( vitamin A contents of 820 IU , 1640 IU , or 2900 IU/MJ ; 1 RE = 3.3 IU vitamin A activity ) when subjects tolerated 0.314 MJ.kg-1.d-1 . Experimental formula feedings were continued until infants weighed approximately 2 kg or until hospital discharge . Vitamin A status as indicated by serum retinol and retinol-binding protein ( RBP ) concentrations significantly decreased during experimental formula feeding at the lowest vitamin A intake . All subjects fed the formula providing the lowest vitamin A intake had hyporetinolemia ( < 0.70 mumol/L , or < 20 micrograms/dL ) , which occurred less frequently ( P < 0.05 ) with the intermediate ( 6 of 20 ) and the high ( 6 of 21 ) vitamin A intakes . Other outcome measures , including increases in weight , length , and head circumference , and ventilatory support and oxygen therapy , were not different among groups . After the end of the experimental formula-feeding period , all infants were fed st and ard infant formulas with a vitamin A content of 715 IU/MJ . In a subset of 19 of these infants , subsequent vitamin A status was monitored at ages 6 - 12 mo and was found to be comparable with that of older children and adults , regardless of the vitamin A content of the formula fed during hospitalization . ( ABSTRACT TRUNCATED AT 250 WORDS Preterm infants were r and omly assigned to receive routine vitamin A supplementation ( Regular A ) or additional vitamin A in intravenous lipids ( High A ) . Because infants with bronchopulmonary dysplasia ( BPD ) have poorer vitamin A status than infants who do not develop BPD , High A and Regular A infants were divided by BPD ( no or yes ) before determining the effects of treatment on intake and plasma concentration of retinol in the first month . Compared with infants without BPD , those with BPD received less retinol ( RE.kg-1.d-1 ) if assigned to Regular A and more if assigned to High A ( BPD by vitamin A interaction , P < 0.002 ) . High A-BPD infants compared with Regular A-BPD infants had significantly higher plasma retinol concentrations in the first month . Retinyl palmitate appears to be an effective adjunct to routine vitamin A administration . Infants most likely to benefit from receiving vitamin A in intravenous lipids are those advanced more slowly to full enteral feeding We conducted a r and omized , double-blind , controlled trial to determine whether vitamin A supplementation from early postnatal life could reduce the morbidity associated with bronchopulmonary dysplasia in very low birth weight ( VLBW ) neonates . Forty VLBW neonates ( 700 to 1300 g birth weight , 26 to 30 weeks gestational age ) , who were oxygen dependent and required mechanical ventilation for at least 72 hours after birth , were given by the intramuscular route either supplemental vitamin A ( retinyl palmitate 2000 IU ) or 0.9 % saline solution on postnatal day 4 and every other day thereafter for a total of 14 injections over 28 days . The study groups were comparable in gestational maturity , clinical characteristics , initial lung disease , and vitamin A status at entry into the trial . Vitamin A administration result ed in significantly higher mean plasma concentrations of vitamin A and retinol-binding protein in treated infants compared with controls . Bronchopulmonary dysplasia was diagnosed in nine of 20 infants given vitamin A supplement and in 17 of 20 control infants ( P less than 0.008 ) . Four of 19 infants in the vitamin A group and 11 of 20 in the control group required mechanical ventilation on study day 28 ( P less than 0.029 ) . The need for supplemental oxygen , mechanical ventilation , and intensive care was reduced in infants given vitamin A supplement compared with controls . Airway infection and retinopathy of prematurity were less frequent in the vitamin A group . We conclude that vitamin A supplementation at the dosage used in this trial in VLBW neonates not only improves their vitamin A status but also appears to promote regenerative healing from lung injury , as evidence d by a decrease in the morbidity associated with bronchopulmonary dysplasia OBJECTIVE Preterm infants show reduced retinal sensitivity at term corrected age compared with newborn term infants . We tested the hypothesis that retinal sensitivity in preterm infants is improved by early , high-dose vitamin A. STUDY DESIGN We report a double-blind , r and omized controlled trial of infants < 32 weeks ' gestation and /or < 1501 g birth weight . Supplemented infants received additional intramuscular vitamin A 10 000 IU 3 times weekly from day 2 for a minimum of 2 weeks or until establishment of oral feeding . Hepatic stores were assessed by relative dose response ( RDR ) . The primary outcome measure was cone-corrected dark-adapted retinal rod sensitivity measured by electroretinogram at 36 weeks ' postmenstrual age ( PMA ) . RESULTS Eighty-nine infants ( 42 supplemented and 47 controls ) were recruited .  Plasma retinol was higher in supplemented infants at 7 and 28 days ( median , 1.0 vs 0.5 μmol/L and 0.7 vs 0.6 μmol/L ; P < .001 and .03 , respectively ) . Neither plasma retinol nor RDR differed between groups at 36 weeks ' PMA . Retinal sensitivity was greater in supplemented infants ( -0.81 vs -0.61 log cd • s • m(-2 ) ; P < .03 ) and was not related to RDR . CONCLUSIONS Early high-dose intramuscular vitamin A supplementation for infants at risk of retinopathy of prematurity  improves retinal function at 36 weeks ' PMA The purpose of this trial was to test the hypothesis that vitamin A adequacy may decrease the incidence of  bronchopulmonary dysplasia ( BPD ) in very-low-birth-weight infants .  Serum vitamin A levels were measured and the effects of two regimens of vitamin A supplementation on the incidence of BPD were compared . There were 24 infants in each of two groups with a mean birth weight less than 1000 g , a mean gestational age of 27 weeks , and similar sexual and racial mixes . In group I ,  vitamin A levels  were measured after 1 week of parenteral nutrition and , if low , the infant was given a 2000-IU supplement intramuscularly three times a week , beginning on the 10th to 14th day of life . In group II , the same supplementation was begun on the second to fourth day of life . In both groups , when enteral feedings reached 60 kcal/kg per day , 2500 IU/d vitamin A was given orally . The incidence of oxygen support at 28 days was similar in both groups , although in group II there was a trend toward less vigorous ventilatory support . chi 2 analysis showed that a significantly smaller proportion of infants in group II had BPD at 36 weeks ' gestational age than in group I. Length of neonatal intensive care unit stay was significantly reduced from 81 to 60 days . We conclude that vitamin A supplementation should be administered early to small , premature infants who are at risk for BPD and that monitoring of plasma levels is essential We conducted a r and omized trial in very low birth weight neonates ( n = 51 ) to determine whether vitamin A supplementation by enteral administration would increase plasma vitamin A concentrations to the same degree as by intramuscular administration .  Mean plasma vitamin A concentrations were significantly higher in the intramuscular-administration group than in the enteral-administration group by postnatal day 7 ; this effect persisted throughout the remainder of the trial . At the dosage used in this trial , vitamin A supplementation by the enteral route is not as effective as that by the intramuscular route in very low birth weight neonates BACKGROUND Low-birth-weight ( LBW ) infants ( < 2,500 g ) are at increased risk of respiratory infection in the first few months of life and have low liver stores of vitamin A. As retinol is essential for respiratory epithelial cell differentiation , deficiency could result in pathological changes in the respiratory epithelium , with respiratory problems . OBJECTIVE A r and omised , double-blind , placebo-controlled trial to investigate the effect of vitamin A supplementation on the incidence and severity of respiratory infections in LBW infants during their first year of life . METHOD One hundred and thirty LBW infants ( gestational age < 36 weeks and birth weight 950 - 1,700 g ) were enrolled in the study . The infants were r and omly allocated to a vitamin A or placebo group . Infants in the vitamin A group received 25,000 IU of vitamin A ( retinyl palmitate , Arovit drops , Roche , Basle , Switzerl and ) on study days 1 , 4 and 8 . Study day 1 was between 36 and 60 hours after delivery . Infants in the placebo group received a placebo ( formulated by Roche ) with a similar appearance and packed in the same dropper bottles as the vitamin A drops . RESULTS Vitamin A supplementation markedly improved serum retinol levels . After the last vitamin A dose , the vitamin A group had higher mean serum retinol concentrations than the placebo group ( 45.77 + /- 17.07 micrograms/dl v. 12.88 + /- 6.48 micrograms/dl , P = 0.0001 ) . There was no evidence of improvement in neonatal or post-neonatal respiratory problems associated with vitamin A supplementation . Vitamin A and placebo groups did not differ in the occurrence or duration of respiratory distress or the need for head-box oxygen . There were also no significant differences in the cumulative probability of developing lower or upper respiratory tract infection through the first year of life . There was a slight suggestion 
    Output:
    