Vitamin D in pregnancy: current perspectives and future directions

As neonatal vitamin D status is determined by circulating maternal 25-hydroxyvitamin D [25(OH)D] concentrations, prevention of maternal vitamin D deficiency during pregnancy is essential for the avoidance of neonatal deficiency. However, a high prevalence of vitamin D deficiency has been extensively reported among gravidae and neonates from ethnic minorities and white populations resident at high latitude. Currently, regulatory authorities recommend vitamin D intakes for pregnant women that are similar to non-pregnant adults of the same age, at 10–15 µg/day (400–600 IU), to meet 25(OH)D thresholds of 25–50 nmol/liter. The lack of pregnancy-specific dietary recommendations is due to inadequate data indicating whether nutritional requirements for vitamin D during pregnancy differ from the non-pregnant state. In addition, there are few dose–response studies to determine the maternal 25(OH)D response to vitamin D intake throughout pregnancy at high latitude. These data are also required to determine vitamin D requirements during pregnancy for prevention of neonatal deficiency, an outcome which is likely to require a higher maternal 25(OH)D concentration than prevention of maternal deficiency only. With regard to the impact of vitamin D on perinatal health outcomes, which could guide pregnancy-specific 25(OH)D thresholds, dietary intervention studies to date have been inconsistent and recent systematic reviews have highlighted issues of low quality and a high risk of bias as drawbacks in the trial evidence to date. Many observational studies have been hampered by a reliance on retrospective data, unclear reporting, suboptimal clinical phenotyping and incomplete subject characterization. Current investigations of vitamin D metabolism during pregnancy have potentially exciting implications for clinical research. This paper provides an update of current dietary recommendations for vitamin D in pregnant women and a synopsis of the evidence relating vitamin D status with maternal and infant health

The architectures of media power: editing, the newsroom, and urban public space

This paper considers the relation of the newsroom and the city as a lens into the more general relation of production spaces and mediated publics. Leading theoretically from Lee and LiPuma’s (2002) notion of ‘cultures of circulation’, and drawing on an ethnography of the Toronto Star, the paper focuses on how media forms circulate and are enacted through particular practices and material settings. With its attention to the urban milieus and orientations of media organizations, this paper exhibits both affinities with but also differences to current interests in the urban architectures of media, which describe and theorize how media get ‘built into’ the urban experience more generally. In looking at editing practices situated in the newsroom, an emphasis is placed on the phenomenological appearance of media forms both as objects for material assembly as well as more abstracted subjects of reflexivity, anticipation and purposiveness. Although this is explored with detailed attention to the settings of the newsroom and the city, the paper seeks to also provide insight into the more general question of how publicness is material shaped and sited

Exploring the concept of functional vitamin D deficiency in pregnancy: impact of the interaction between 25-hydroxyvitamin D and parathyroid hormone on perinatal outcomes

Background: Associations of vitamin D with perinatal outcomes are inconsistent and few studies have considered the wider calcium metabolic system. Objectives: We aimed to explore functional vitamin D deficiency in pregnancy by investigating associations between vitamin D status, parathyroid hormone (PTH), and perinatal outcomes. Design: SCOPE (Screening for Pregnancy Endpoints) Ireland is a prospective cohort study of low-risk, nulliparous pregnant women. We measured serum 25-hydroxyvitamin D [25(OH)D] and PTH at 15 wk of gestation in 1754 participants. Results: Mean ± SD 25(OH)D was 56.6 ± 25.8 nmol/L (22.7 ± 10.3 ng/mL) and geometric mean (95% CI) PTH was 7.84 pg/mL (7.7, 8.0 pg/mL) [0.86 pmol/L (0.85, 0.88 pmol/L)]. PTH was elevated in 34.3% of women who had 25(OH)D <30 nmol/L and in 13.9% of those with 25(OH)D ≥75 nmol/L. Whereas 17% had 25(OH)D <30 nmol/L, 5.5% had functional vitamin D deficiency, defined as 25(OH)D <30 nmol/L with elevated PTH. Elevated mean arterial pressure (MAP), gestational hypertension, pre-eclampsia, and small-for-gestational-age (SGA) birth were confirmed in 9.2%, 11.9%, 3.8%, and 10.6% of participants, respectively. In fully adjusted regression models, neither low 25(OH)D nor elevated PTH alone increased the risk of any individual outcome. The prevalence of elevated MAP (19.1% compared with 9.7%) and SGA (16.0% compared with 6.7%) were highest (P < 0.05) in those with functional vitamin D deficiency compared with the reference group [25(OH)D ≥75 nmol/L and normal PTH]. The adjusted prevalence ratio (PR) and RR (95% CIs) for elevated MAP and SGA were 1.83 (1.02, 3.27) and 1.53 (0.80, 2.93), respectively. There was no effect of functional vitamin D deficiency on the risk of gestational hypertension (adjusted RR: 1.00; 95% CI: 0.60, 1.67) or pre-eclampsia (adjusted RR: 1.17; 95% CI: 0.32, 4.20). Conclusion: The concept of functional vitamin D deficiency, reflecting calcium metabolic stress, should be considered in studies of vitamin D in pregnancy. The SCOPE pregnancy cohort is registered at http://www.anzctr.org.au as ACTRN12607000551493

Interactions between vitamin D status, calcium intake and parathyroid hormone concentrations in healthy pregnant women

Emerging evidence highlights the potential of the vitamin D and calcium metabolic system to impact pregnancy outcomes and adverse effects of vitamin D-parathyroid hormone (PTH) interactions on perinatal health have been reported(1,2). PTH concentrations reflect homeostasis in the calcium metabolic system, and can be impacted by calcium intake as well as circulating 25-hydroxyvitamin D [25(OH)D] concentrations, reflecting vitamin D status. Little explored in pregnancy, we aimed to examine the relative importance of vitamin D status and calcium intake on PTH concentrations among healthy pregnant women. This was a cross-sectional analysis of 142 white-skinned participants of mean (SD) 14 (2) weeks’ gestation at baseline of a dose-response randomised controlled trial of vitamin D [NCT02506439](3). Serum 25(OH)D was measured by a CDC-accredited LC-MS/MS method and calcium intakes were estimated using a validated quantitative food frequency questionnaire(4). Serum albumin-corrected calcium and intact PTH were measured by colorimetric assay (Randox Laboratories Ltd.) and ELISA (MD Biosciences Inc.), respectively. Serum 25(OH)D was stratified at 50 nmol/L and calcium intakes by < 800, 800–1000 and ≥ 1000 mg/day according to the Institute of Medicine(5). After log transformation of PTH, we used Pearson’s correlations and two-way ANOVA to explore effects of calcium intakes and 25(OH)D on PTH. Geometric mean (95% CI) PTH concentration was 9·24 (8·37, 10·19) pg/mL. Mean (SD) 25(OH)D and calcium intake were 54·9 (22·6) nmol/L and 1182·5 (485·8) mg/day, respectively. 44% of participants had a 25(OH)D < 50 nmol/L and calcium intake was < 800 and ≥ 1000 mg/day in 22% and 63%, respectively. PTH was inversely correlated with vitamin D status (r = −0·311, P < 0·01), but not calcium intake (r = −0·087) or serum calcium (r = 0·057). There was no evidence of an interaction between calcium intake and 25(OH)D on PTH concentration (P = 0·941). There was a statistically significant main effect of serum 25(OH)D (P = 0·025) but not calcium intake (P = 0·822) on PTH. To conclude, in this group of healthy pregnant women with largely sufficient calcium intake, vitamin D status, but not calcium intake was important for maintaining calcium homeostasis

Adherence to the infant vitamin D supplementation policy in Ireland

Purpose: From September 2010 until November 2019, Ireland’s infant vitamin D supplementation policy recommended administration of 5 μg/day of vitamin D3 from birth to 12 months to all infants, regardless of feeding method. This study aims to examine policy adherence. Methods: In the prospective COMBINE birth cohort study (recruited 2015–2017), detailed longitudinal supplement data were examined in 364 infants across the first year of life, according to product type, dose, frequency, and duration. Vitamin D supplement use at 2, 6, and 12 months in COMBINE was compared with the BASELINE cohort (recruited 2008–2011, n = 1949). Results: In COMBINE, 92% of infants initiated supplementation at birth. The median supplementation duration was 51 (40, 52) weeks, with a range of 3–52 weeks. While supplementing, most parents (92%) used an exclusive vitamin D supplement as recommended and 88% gave 5 µg/day. Half (51%) gave vitamin D daily and a further 33% supplemented at least 3–6 times/week. Overall, 30% adhered fully to the policy, providing 5 µg vitamin D3 daily from birth to 12 months. A further 16% were broadly compliant, giving 5 µg frequently for the full 12 months. Vitamin D supplement use at 2, 6, and 12 months in COMBINE was 93%, 89%, and 72%, considerably higher than our earlier BASELINE cohort at 49%, 64%, and 44% at the same time points (all P < 0.001). Conclusions: We report a high level of vitamin D supplementation initiation at birth, with full to broad policy adherence among more than half of infants. There is scope to improve overall compliance by focusing on supplementation frequency

Prolonged dual anti-platelet therapy in stable coronary disease: a comparative observational study of benefits and harms in unselected versus trial populations

Objective: To estimate the potential magnitude in unselected patients of the benefits and harms of prolonged dual antiplatelet therapy after acute myocardial infarction seen in selected patients with high risk characteristics in trials. Design: Observational population based cohort study. Setting: PEGASUS-TIMI-54 trial population and CALIBER (ClinicAl research using LInked Bespoke studies and Electronic health Records). Participants: 7238 patients who survived a year or more after acute myocardial infarction. Interventions: Prolonged dual antiplatelet therapy after acute myocardial infarction. Main outcome measures: Recurrent acute myocardial infarction, stroke, or fatal cardiovascular disease. Fatal, severe, or intracranial bleeding. Results: 1676/7238 (23.1%) patients met trial inclusion and exclusion criteria (“target” population). Compared with the placebo arm in the trial population, in the target population the median age was 12 years higher, there were more women (48.6% v 24.3%), and there was a substantially higher cumulative three year risk of both the primary (benefit) trial endpoint of recurrent acute myocardial infarction, stroke, or fatal cardiovascular disease (18.8% (95% confidence interval 16.3% to 21.8%) v 9.04%) and the primary (harm) endpoint of fatal, severe, or intracranial bleeding (3.0% (2.0% to 4.4%) v 1.26% (TIMI major bleeding)). Application of intention to treat relative risks from the trial (ticagrelor 60 mg daily arm) to CALIBER’s target population showed an estimated 101 (95% confidence interval 87 to 117) ischaemic events prevented per 10 000 treated per year and an estimated 75 (50 to 110) excess fatal, severe, or intracranial bleeds caused per 10 000 patients treated per year. Generalisation from CALIBER’s target subgroup to all 7238 real world patients who were stable at least one year after acute myocardial infarction showed similar three year risks of ischaemic events (17.2%, 16.0% to 18.5%), with an estimated 92 (86 to 99) events prevented per 10 000 patients treated per year, and similar three year risks of bleeding events (2.3%, 1.8% to 2.9%), with an estimated 58 (45 to 73) events caused per 10 000 patients treated per year. Conclusions: This novel use of primary-secondary care linked electronic health records allows characterisation of “healthy trial participant” effects and confirms the potential absolute benefits and harms of dual antiplatelet therapy in representative patients a year or more after acute myocardial infarction

A detailed exploration of early infant milk feeding in a prospective birth cohort study in Ireland: combination feeding of breast milk and infant formula and early breast-feeding cessation

Breast-feeding initiation and continuation rates in the UK and Ireland are low relative to many European countries. As a core outcome of the prospective Cork Nutrition and Development Maternal-Infant Cohort (COMBINE) study (Cork, Ireland), we aimed to describe infant milk feeding practices in detail and examine the prevalence and impact of combination feeding of breast milk and infant formula on breast-feeding duration. COMBINE recruited 456 nulliparous mothers (2015â 2017) for maternalâ infant follow-up via interview at hospital discharge (median 3 (interquartile range (IQR) 2, 4) d (n 453)), 1 (n 418), 2 (n 392), 4 (n 366), 6 (n 362) and 9 (n 345) months of age. Median maternal age was 32 (IQR 29, 34) years, 97 % of mothers were of white ethnicity, 79 % were Irish-born and 75 % were college-educated. Overall, 75 % breastfed to any extent at discharge and 44 % breastfed solely. At 1, 2, 4, 6 and 9 months, respectively, 40, 36, 33, 24 and 19 % breastfed solely. Combination feeding of breast milk and infant formula was common at discharge (31 %) and 1 month (20 %). Reasons for combination feeding at 1 month included perceived/actual hunger (30 %), healthcare professional advice (31 %) and breast-feeding difficulties (13 %). Of mothers who breastfed to any extent at discharge, 45 % stopped within 4 months. Mothers who combination fed were more likely to cease breast-feeding than those who breastfed solely (relative risk 2·3 by 1 month and 12·0 by 2 months). These granular data provide valuable insight to early milk feeding practices and indicate that supporting early breast-feeding without formula use may be key to the successful continuation of breast-feeding

“It’s Like Hating Puppies!” Employee Disengagement and Corporate Social Responsibility

Corporate social responsibility (CSR) has been linked with numerous organizational advantages, including recruitment, retention, productivity, and morale, which relate specifically to employees. However, despite specific benefits of CSR relating to employees and their importance as a stakeholder group, it is noteworthy that a lack of attention has been paid to the individual level of analysis with CSR primarily being studied at the organizational level. Both research and practice of CSR have largely treated the individual organization as a “black box,” failing to account for individual differences amongst employees and the resulting variations in antecedents to CSR engagement or disengagement. This is further exacerbated by the tendency in stakeholder theory to homogenize priorities within a single stakeholder group. In response, utilizing case study data drawn from three multinational tourism and hospitality organizations, combined with extensive interview data collected from CSR leaders, industry professionals, engaged, and disengaged employees, this exploratory research produces a finer-grained understanding of employees as a stakeholder group, identifying a number of opportunities and barriers for individual employee engagement in CSR interventions. This research proposes that employees are situated along a spectrum of engagement from actively engaged to actively disengaged. While there are some common drivers of engagement across the entire spectrum of employees, differences also exist depending on the degree to which employees, rather than senior management, support corporate responsibility within their organizations. Key antecedents to CSR engagement that vary depending on employees’ existing level of broader engagement include organizational culture, CSR intervention design, employee CSR perceptions, and the observed benefits of participation

Into the newsroom: using actor network theory to investigate the construction of news facts

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