Penni D. Hicks

High rates of mortality and morbidity occur in infants with parenteral nutrition-associated cholestasis.

BACKGROUND Extremely few data are available about the natural history of parenteral nutrition (PN)-associated cholestasis. The authors evaluated a cohort of infants at a large center to determine the outcome of PN-associated cholestasis in infants with some gastrointestinal function. METHODS The authors reviewed the records of all infants admitted to a level 3 neonatal intensive care unit over a 16-month period who had the diagnosis of PN-associated cholestasis. Records were reviewed in these infants for course of cholestasis, laboratory values, outcome, and infection rate. RESULTS Sixty-six patients were admitted who met the study criteria. There were 10 deaths and 1 referral for liver transplant (Death/TPlant) (17%) in the first year of life. All Death/TPlant infants had at least 1 positive blood culture after the onset of cholestasis. Maximum conjugated bilirubin (MaxCB) in Death/TPlant infants was 15.7 +/- 2.2 (SEM) compared to 8.4 +/- 1.0 mg/dL in babies who recovered. Of 21 infants with a MaxCB > or =10.0, Death/TPlant occurred in 8/21 (38%). Of 40 babies with positive blood cultures, 11 were in the Death/TPlant group vs no deaths among the 25 without positive blood cultures. Average time to resolution from the MaxCB to a CB <2.0 mg/dL was 66 +/- 7 days (n = 49). CONCLUSIONS Infants with PN-associated cholestasis have high rates of mortality despite the presence of some gastrointestinal function. These data support further evaluation and the development of novel forms of therapy for babies with parenteral-associated CB > or =2 mg/dL with emphasis on interventions for infants with a CB >10 mg/dL.

Higher Serum 25-Hydroxyvitamin D Levels in School-Age Children Are Inconsistently Associated with Increased Calcium Absorption

CONTEXT Increasing serum 25-hydroxyvitamin D (25-OHD) in adults may enhance calcium absorption (Ca-abs). There are few similar pediatric data leading to uncertainty about the optimal target for 25-OHD to maximize Ca-abs. OBJECTIVE Our objective was to evaluate the relationship between 25-OHD and Ca-abs in a large cohort of school-age children and adolescents. DESIGN We evaluated data from 439 Ca-abs measurements performed using dual-tracer stable isotope techniques conducted at our center over a 15-yr period in 251 healthy children, 4.9-16.7 yr of age. RESULTS Serum 25-OHD ranged from 28 to 197 nmol/liter (mean 85 +/- 2 nmol/liter) (sem). Total Ca-abs (intake times fractional absorption) were significantly correlated to 25-OHD in the whole population (r = 0.16, P = 0.001). This relationship was closer in the 197 studies in early puberty (Tanner 2 or 3, r = 0.35, P < 0.001) and not significant in pre- or late pubertal subjects. For the whole population, fractional Ca-abs adjusted for calcium intake were slightly but significantly higher at 25-OHD of 28-50 nmol/liter (0.344 +/- 0.019) compared with 25-OHD of 50-80 nmol/liter (0.280 +/- 0.014) or 25-OHD greater than 80 nmol/liter (0.297 +/- 0.015, P < 0.01 for each), suggesting adaptation to moderately low 25-OHD values. CONCLUSION There is no consistent pattern of relationship between 25-OHD and either fractional or total calcium absorption in school-age children. However, there appears to be a modest calcium absorptive response to higher 25-OHD during early puberty.

Pubertal Girls Only Partially Adapt to Low Dietary Calcium Intakes

We evaluated the effects of low calcium in the diets of young adolescent girls. We measured calcium absorption and excretion using stable isotopes. We found partial adaptation to low intakes but a persistent large deficit relative to recommended intakes. Low calcium intakes pose a substantial risk of inadequate calcium retention.

Calcium Absorption in Very Low Birth Weight Infants with and without Bronchopulmonary Dysplasia

OBJECTIVE To evaluate the effects of early bronchopulmonary dysplasia (BPD) on calcium (Ca) metabolism and growth in very low birth weight (VLBW) infants. STUDY DESIGN A dual-tracer, stable isotope method was used to assess Ca absorption in VLBW infants. Infants with early BPD received energy-dense feedings and mild fluid restriction. RESULTS Sixteen of 41 preterm infants were classified as having early BPD. Fractional Ca absorption (early BPD, 58.4 ± 4.6% versus no early BPD, 50.3 ± 4.0%, P = .2), total Ca absorption (early BPD, 127 ± 14 mg/kg/d versus no early BPD, 104 ± 9 mg/kg/d, P = .9), and Ca retention (early BPD, 99.6 ± 10.0 mg/kg/d versus no early BPD, 91.0 ± 9.8 mg/kg/d, P = .2) were similar among groups. There was no significant difference in weight gain, linear growth, or head circumference growth between groups. CONCLUSIONS The ability of VLBW infants with early BPD and fluid restriction to grow and accrete calcium is similar to those without early BPD. The use of high caloric density feedings in VLBW infants with early BPD can help achieve bone and overall growth outcomes close to those achievable in utero.

Orange but not apple juice enhances ferrous fumarate absorption in small children.

Objective: Ferrous fumarate is a common, inexpensive iron form increasingly used instead of ferrous sulfate as a food iron supplement. However, few data exist as to whether juices enhance iron absorption from ferrous fumarate. Subjects and Methods: We studied 21 children, ages 4.0 to 7.9 years using a randomized crossover design. Subjects consumed a small meal including a muffin containing 4 mg 57Fe as ferrous fumarate and either apple (no ascorbic acid) or orange juice (25 mg ascorbic acid). They were separately given a reference dose of 58Fe (ferrous sulfate) with ascorbic acid. Results: Iron absorption increased from 5.5% ± 0.7% to 8.2% ± 1.2%, P < 0.001 from the muffins given with orange juice compared with muffins given with apple juice. The absorption of ferrous fumarate given with orange juice and enhancement of absorption by the presence of juice were significantly positively related to height, weight, and age (P < 0.01 for each). Although iron absorption from ferrous fumarate given with apple juice was significantly inversely associated with the (log transformed) serum ferritin, the difference in absorption between juice types was not (P > 0.9). Conclusions: These data demonstrate an overall benefit to iron absorption from ferrous fumarate provided with orange juice. The effect was age related such that in children older than 6 years of age, there was a nearly 2-fold increase in iron absorption from ferrous fumarate given with orange juice.