R McCarthy

Vitamin D nutritional status in preterm infants and response to supplementation.

Little is known about vitamin D status in preterm infants and their response to supplementation. To investigate this, we assessed serum 25-hydroxyvitamin D (25OHD) levels using RIA in a consecutive sample of stable preterm very low birth weight (VLBW) infants (born ≤ 32 weeks gestation or birth weight ≤ 1·5 kg), and we explored associated factors. Serum 25OHD level was first assessed once infants were tolerating feeds (n 274). If this first 25OHD level was below 50 nmol/l (20 ng/ml), which is the level associated with covering requirements in terms of skeletal health in the majority, then we recommended prolonged augmented vitamin D intake ( ≥ 10 μg (400 IU) daily) from a combination of fortified feeds and vitamin supplements and follow-up re-assessment at approximately 6 weeks corrected age (n 148). The first assessment, conducted at a median for chronological age of 18 (interquartile range (IQR) 11-28) d, found that 78 % had serum 25OHD levels below 50 nmol/l. Multivariable analysis demonstrated that the determinants of serum 25OHD levels were duration of vitamin D supplementation and gestational age at birth (r 2 0·215; P< 0·001). At follow-up, after a median of 104 (IQR 78-127) d, 87 % achieved levels ≥ 50 nmol/l and 8 % had levels >125 nmol/l, a level associated with potential risk of harm. We conclude that low 25OHD levels are an issue for preterm VLBW infants, warranting early nutritional intervention. In infants with serum 25OHD levels < 50 nmol/l, a vitamin D intake of ≥ 10 μg (400 IU) daily achieves target levels in the majority; however, further work is needed to determine the exact dose to safely meet target levels without overcorrection.

The Association of Vitamin D Status with Acute Respiratory Morbidity in Preterm Infants

OBJECTIVE To assess the association between serum 25-hydroxyvitamin D (25OHD) levels and outcomes in preterm infants (<32 weeks gestation). STUDY DESIGN Serum 25OHD was measured in mothers and their infants within 24 hours of birth, before the start of enteral vitamin D supplementation, and at discharge from the neonatal intensive care unit. We evaluated the associations between vitamin D status and various early preterm outcomes. RESULTS Ninety-four preterm infants and their mothers were included; 92% of the infants had a 25OHD level≤50 nmol/L (20 ng/mL), and 64% had a 25OHD level<30 nmol/L (12 ng/mL). A low 25OHD level (<30 nmol/L) in preterm infants at birth was associated with increased oxygen requirement (P=.008), increased duration of intermittent positive-pressure ventilation during resuscitation at delivery (P=.032), and greater need for assisted ventilation (P=.013). CONCLUSION We observed a high prevalence of low 25OHD (<30 nmol/L), and found an association between vitamin D status and acute respiratory morbidity in preterm infants after birth.

Vitamin D and neonatal immune function.

Abstract Vitamin D deficiency is widespread in the neonatal and paediatric population of northern latitudes, particularly in children of African, Middle Eastern and Asian ethnicity. This is associated with diminished immune function and increases the risk of Th1 autoimmune diseases like type 1 diabetes. Epidermiological studies have also shown a link between vitamin D deficiency in children and a more severe course of illness with lower respiratory tract infection or Respiratory Syncitial Virus (RSV) bronchiolitis. The mechanism by which vitamin D enhances immunity is complex. It acts through the innate immune system by inducing antimicrobial peptides in epithelial cells, neutrophils and macrophages. The role of Vitamin D in neonatal and paediatric immunomodulation requires further study.

Towards evidence based medicine for paediatricians. Question 2. What is the ideal dose of vitamin D supplementation for term neonates

During a well-baby check, a mother asked for the consultants recommendation on the ideal dose and type of vitamin D formulation for her infant. She intends to breastfeed her baby exclusively. Her baby was born at 39 weeks gestation by spontaneous vaginal delivery. In a normal term neonate [patient], what is the optimal dose of vitamin D supplementation [intervention] to prevent vitamin D deficiency and rickets [outcome]? ### Primary sources MEDLINE was searched via PubMed from 1990 to July 2011. The advanced search mode was used with the terms ‘vitamin D’ and ‘neonates’ and ‘supplementation’. ### Secondary sources A search of the Cochrane Library was conducted using the search terms ‘vitamin D’ and ‘infants’. Vitamin D is essential for good bone health and insufficient levels are linked to rickets in children.1 5 A resurgence of vitamin D insufficiency and nutritional rickets has been reported across many countries.1 Studies in infants and children are also exploring the association between vitamin D insufficiency and type 1 diabetes mellitus as well as inflammatory diseases.1 2 There …

Relationship between vitamin D and alkaline phosphatase in very-low-birthweight infants

Vitamin D deficiency is increasingly recognised in neonates, especially those born to high-risk mothers.1 Term infants at high risk of vitamin D deficiency have higher mean alkaline phosphatase (ALP) activity than controls, indicating increased bone turnover.1 Despite this, ALP activities remain within the normal range in these high-risk infants. There is little research on vitamin D deficiency in very-low-birthweight (VLBW) infants, who are at high risk of bone disease due to osteopenia of prematurity (OP) and potentially maternal or nutritional vitamin D deficiency. The increase in breast feeding with inadequate supplementation …

Non-blood group-specific red blood cell transfusions in preterm infants and necrotizing enterocolitis.

To the Editor: We were interested in the report by Blau et al on transfusion-related gut injury (TRAGI) as an etiology for necrotizing enterocolitis (NEC). We hypothesized that TRAGI might be an immune-mediated antigenic response to receiving non group-specific red blood cell (RBC) transfusions. RBC alloantibody formation in infants aged <4 months is rare, and thus all neonates receive group O blood. We used a prospective database of confirmed cases of NEC (Bell’s staging

G105 Pregnancy and Premature Neonatal Outcomes in Vitamin D Deficiency

2) from 2006-2010 in a level III neonatal intensive care unit. Out of 44 177 births over the 4-year study period, 602 infants (1.3%) were born at a weight of <1500 g, of whom 39 developed NEC. Nine infants with a birth weight (BW) of >1500 g also developed NEC, for a total of 48 cases of NEC. A total of 779 RBC transfusions were performed, of which 367 (47%) were blood group-specific. In comparison, 17 of 30 transfusions (56.6%) were group-specific in the infants who developed NEC. The distribution of blood groups transfused was similar in infants who developed NEC and those who did not. However, 16 (53%) were O-positive developed NEC, whereas 291 (37%) did not. The mean day of onset of NEC was day of life 22 14 in the unmatched group and day 24 14 in the matched group (P = .70). The mean BW was 801 230 g in the matched group and 931 314 g in the unmatched group (P = .22). We classified the timing of RBC transfusion and the onset of NEC as follows: RBC transfusion 48 hours before the onset of NEC symptoms (transfusion-associated NEC [TAN]), RBC transfusion >48 hours before the onset of NEC symptoms (non–transfusion-associated NEC [TIN]), and NEC with no RBC transfusion before onset of symptoms. Four neonates were in the TAN group, 26 were in the TIN group, and 18 did not undergo transfusion. The mean gestational age (GA) was 28 3 weeks in the TAN group, 26 2 weeks in the TIN group, and 31 3 weeks in the never-transfused group (P < .001). Mean BW was 971 522 g in the TAN group, 860 244 g in the TIN group, and 1551 815 g in the never-tranfused group (P < .001). The mean GA at symptom onset was 31 1 weeks in the TAN group, 30 3 weeks in the TIN group, and 32 3 weeks in the nevertransfused group (P < .003). The median day of onset of NEC was day 22 15 in the TAN group, day 23 14 in the TIN group, and 11 8 days in the never-transfused group (P < .01). Non–group-specific RBC transfusions were not associated with the development of NEC and thus remain a safe practice in neonatal blood transfusion. We had a lower incidence of TRAGI compared with Blau et al (8.3% vs 25%). We found that infants with TAN had lower BW, lower GA,

Vitamin D deficiency is associated with altered hematologic indexes in very low birth weight infants.

Background Hypovitaminosis D is widespread among pregnant women and their infants. Recent studies implicate Vitamin D as having anti-inflammatory effects which may be beneficial in preterm infants who are at high risk of inflammatory disorders. Aim To assess serum 25OHD status in preterm infants in NICU and their mothers and any associations between vitamin D levels and outcome. Methods Serum 25OHD levels were prospectively evaluated by radioimmunoassay from preterm (< 32 weeks gestation) infants and their mothers at birth. 25OHD levels were correlated with outcomes in NICU including Necrotizing Enterocolitis (NEC), Retinopathy of Prematurity (ROP) and Ventilation days. Results A total of 70 preterm infants/mothers pairs were included. 95% of preterm infants were 25OHD deficient (<50nmol/L) and 64% were severely deficient (<30nmol/L) at birth. 90% of mothers were 25OHD deficient (<50nmol/L) and 46% were severely deficient (<30nmol/L). There were no differences in mean gestational age (G.A) and birth weights (B. Wt) between preterm infants with severe deficicncy versus the remaining preterm infants. Preterm infants with severe vitamin d deficiency had a higher incidence of NEC (p = 0.03); longer duration of assisted ventilation (p = 0.04) and higher incidence of ROP (p = 0.06) (Table 1). Abstract G105 Table 1 Groups G.A ±SD (weeks) B.Wt ±SD (kg) Ventilation (days) NEC (n) ROP (n) <30nmol/L 28.9 ± 2.0 1.2 ± 0.3 80 14 11 >30nmol/L 29.1 ± 2.1 1.2 ± 0.3 37 3 2 p Value 0.53 0.71 0.04 0.03 0.06 Conclusions Severe hypovitaminosis D is associated with adverse outcomes especially NEC and respiratory morbidity in this cohort of preterm NICU infants. Vitamin D supplemntation in pregnancy may modify these morbidities.

Vitamin D nutrient intake for all life stages

To the Editor: The article by Chesney highlighted the vital role of vitamin D in immune function. VitaminD plays an important role in both skeletal and nonskeletal health. There are little data on vitaminD status in very lowbirthweight (VLBW) infants who are at particular risk of bone disease because of osteopenia of prematurity, sepsis, diuretic therapy, deprivation of the estrogen/progesterone surge in late pregnancy, in addition to the potential for maternal and nutritional vitamin D deficiency. We aimed to assess vitamin D levels and associated full blood counts in a cohort of VLBW infants. Convalescent, stable VLBW infants (birth weight#1.5 kg or 50 nmol/L (20 ng/mL), and the remaining 77 had levels 50 nmol/L had increased platelets and monocytes at the time of vitamin D sampling. In addition their white blood cell counts, absolute neutrophil counts, and immature neutrophil counts were increased at their highest blood count during hospitalization (Table). In addition these infants had increased incidences of chronic lung disease and duration of oxygen therapy. In conclusion, vitamin D deficiency is common in VLBW infants. It is associated with decreased leukocyte counts and less immature neutrophils. The role of vitamin D in neonatal immune function requires further study.