• Pregnancy in dark winters: implications for fetal bone growth?

      Walsh, Jennifer M; Kilbane, Mark; McGowan, Ciara A; McKenna, Malachi J; McAuliffe, Fionnuala M; UCD Obstetrics and Gynaecology, School of Medicine and Medical Science, University College Dublin, National Maternity Hospital, Dublin, Ireland. (Elsevier, 2013-01)
      To prospectively examine the prevalence of hypovitaminosis D in pregnancy and to correlate maternal and fetal vitamin D to fetal anthropometry.
    • The relationship between maternal and fetal vitamin D, insulin resistance, and fetal growth.

      Walsh, Jennifer M; McGowan, Ciara A; Kilbane, Mark; McKenna, Malachi J; McAuliffe, Fionnuala M; UCD Obstetrics and Gynaecology, School of Medicine and Medical Science, University College Dublin, National Maternity Hospital, Dublin, Ireland (2013-05)
      Evidence for a role of vitamin D in maintaining normal glucose homeostasis is inconclusive. We sought to clarify the relationship between maternal and fetal insulin resistance and vitamin D status. This is a prospective cohort study of 60 caucasian pregnant women. Concentrations of 25-hydroxyvitamin D (25-OHD), glucose, insulin, and leptin were measured in early pregnancy and at 28 weeks. Ultrasound at 34 weeks assessed fetal anthropometry including abdominal wall width, a marker of fetal adiposity. At delivery birth weight was recorded and fetal 25-OHD, glucose, C-peptide, and leptin measured in cord blood. Insulin resistance was calculated using the Homeostasis Model Assessment (HOMA) equation. We found that those with lower 25-OHD in early pregnancy had higher HOMA indices at 28 weeks, (r = -.32, P = .02). No significant relationship existed between maternal or fetal leptin and 25-OHD, or between maternal or fetal 25-OHD and fetal anthropometry or birth weight. The incidence of vitamin D deficiency was high at each time point (15%-45%). These findings lend support to routine antenatal supplementation with vitamin D in at risk populations.
    • Towards evidence based medicine for paediatricians. Question 2. What is the ideal dose of vitamin D supplementation for term neonates?

      Onwuneme, Chike; Carroll, Aoife; McCarthy, Roberta; Kilbane, Mark; McKenna, Malachi; Murphy, Nuala; Molloy, Eleanor J; Department of Paediatrics, National Maternity Hospital, Holles Street, Dublin 2, Ireland. chike.onwuneme@gmail.com (2012-04)
    • Vitamin D and neonatal immune function.

      Clancy, N; Onwuneme, C; Carroll, A; McCarthy, R; McKenna, M J; Murphy, N; Molloy, E J (2013-05)
      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.
    • Vitamin D deficiency is associated with altered hematologic indexes in very low birth weight infants.

      Velagapudi, Amit; McCarthy, Roberta; McKenna, Malachi; Brady, Jennifer; Murray, Barbara; Molloy, Eleanor J (The Journal of pediatrics, 2011-04)
    • Vitamin D nutritional status in preterm infants and response to supplementation.

      McCarthy, Roberta A; McKenna, Malachi J; Oyefeso, Oyinkansola; Uduma, Ogenna; Murray, Barbara F; Brady, Jennifer J; Kilbane, Mark T; Murphy, John F; Twomey, Anne; O' Donnell, Colm P; et al. (2013-07-14)
      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.