Vitamin D deficiency has increased in the last few decades owing to changing lifestyles and dietary habits.¹ Vitamin D is an essential hormone for bone mineralization² that begins in utero and continues throughout childhood until early adulthood, when peak bone mass is reached, which is an important determinant for osteoporosis later in life.^3,4 A decreased bone mineral status has been associated with risk of fractures already in childhood.⁵ Furthermore, severe vitamin D deficiency in childhood can lead to craniotabes and rickets,⁶ but studies examining the effect of maternal gestational vitamin D status on offspring anthropometrics and bone mineralization have shown contradictory results.

This long-term follow-up of a randomized trial reporting no apparent effect of high-dose vs standard-dose prenatal vitamin D supplementation on wheezing in chil

Asthma is the most common chronic disease in childhood and a rise in prevalence has been observed concomitantly with changing dietary habits in the Western world. This change has favored a more Westernized diet characterized by high intake of processed food and fat in contrast to a Mediterranean diet high in fruit, vegetable and fish intake. This has resulted in a decreased intake of several antioxidants and micronutrients including n‐3 long‐chained polyunsaturated fatty acids and vitamin D that are speculated to have anti‐inflammatory effects and hold immunoregulatory properties. Several observational studies have investigated associations between dietary intake and wheeze and asthma but only few large well‐conducted randomized controlled trials (RCTs) have been performed investigating the primary preventive effect of micronutrient supplementations. Currently, the recommendations from the Global Initiative for Asthma (GINA) for primary prevention of asthma in children do not include maternal dietary changes or supplementations during pregnancy, although the most recent report mentions both specific dietary patterns and micronutrients as potential protective supplementation regimes. This review will present the current literature and future research needs focusing on primary and secondary prevention of both early and late childhood asthma from dietary intake during pregnancy and early childhood to highlight potential preventive effects of specific dietary patterns and micronutrient supplements, which may facilitate the planning of future clinical trials in search of a preemptive strategy.

The pregnancy period and first days of a newborn’s life is an important time window to ensure a healthy development of the baby. This is also the time when the mother and her baby are exposed to the same environmental conditions and intake of nutrients, which can be determined by assessing the blood metabolome. For this purpose, dried blood spots (DBS) of newborns are a valuable sampling technique to characterize what happens during this important mother-child time window. We used metabolomics profiles from DBS of newborns (age 2–3 days) and maternal plasma samples at gestation week 24 and postpartum week 1 from $n=664$ mother-child pairs of the Copenhagen Prospective Studies on Asthma in Childhood 2010 (COPSAC${}_{2010}$) cohort, to study the vertical mother-child transfer of metabolites. Further, we investigated how persistent the metabolites are from the newborn and up to 6 months, 18 months, and 6 years of age. Two hundred seventy two metabolites from UPLC-MS (Ultra Performance Liquid Chromatography-Mass Spectrometry) analysis of DBS and maternal plasma were analyzed using correlation analysis. A total of 11 metabolites exhibited evidence of transfer ($R>0.3$), including tryptophan betaine, ergothioneine, cotinine, theobromine, paraxanthine, and N6-methyllysine. Of these, 7 were also found to show persistence in their levels in the child from birth to age 6 years. In conclusion, this study documents vertical transfer of environmental and food-derived metabolites from mother to child and tracking of those metabolites through childhood, which may be of importance for the child’s later health and disease.

Importance: A high infection burden in early childhood is common and a risk factor for later disease development. However, longitudinal birth cohort studies investigating early-life infection burden and later risk of infection and antibiotic episodes are lacking.Objective: To investigate whether early-life infection burden is associated with a later risk of infection and systemic antibiotic treatment episodes in childhood.Design, Setting, and Participants: This longitudinal cohort study of children from birth to age 10 or 13 years included data from the Danish population-based Copenhagen Prospective Studies on Asthma in Childhood (COPSAC) birth cohort between November 2008 to November 2010. Children were monitored for infection diagnoses and systemic antibiotic prescriptions from national databases until February 1, 2024, by which time they had completed the age 10- or 13-year visit. Children with immune deficiencies or congenital diseases were excluded.Exposures: Daily diary-registered common infection episodes of cold, acute otitis media, tonsillitis, pneumonia, gastroenteritis, and fever episodes from birth to 3 years.Main Outcome and Measures: After age 3 years, the incidence of moderate to severe infection diagnoses and systemic antibiotic prescriptions were estimated using adjusted incidence rate ratios (AIRRs) calculated from quasi-Poisson regression models. All analyses were adjusted for social and environmental confounders.Results: A total of 614 children (317 male [51.6%]) with diary data from birth to 3 years had completed follow-up until age 10 or 13 years. No differences in baseline characteristics between the children having vs not having available diary data were noted. Children with a high vs low burden of diary-registered infections between birth and 3 years (ie, equal to and above vs below the median of 16) had an increased risk of later moderate to severe infections (181 vs 87 episodes; AIRR, 2.39; 95% CI, 1.52-3.89) and systemic antibiotic treatments (799 vs 623 episodes; AIRR, 1.34; 95% CI, 1.07-1.68) until age 10 or 13 years. Each diary infection episode also increased the later risk of moderate to severe infections (AIRR, 1.05; 95% CI, 1.02-1.08) and systemic antibiotic treatments (AIRR, 1.02; 95% CI, 1.01-1.04). Subtype analyses showed significant associations between each cold, acute otitis media, pneumonia, gastroenteritis, and fever episode between birth and 3 years and risk of later moderate to severe infections or systemic antibiotic treatments.Conclusions and relevance: This longitudinal cohort study suggests that early-life infection burden may continue throughout childhood and is associated with later antibiotic treatments independent of social and environmental risk factors. These findings are important for prognosis and follow-up of children experiencing a high burden of common infections in early life.

Background: Evidence suggests maternal pregnancy dietary intake and nutrition in the early postnatal period to be of importance for the newborn child's health. However, studies investigating diet‐related metabolites transferred from mother to child on disease risk in childhood are lacking. We sought to investigate the influence of vertically transferred metabolites on risk of atopic diseases and infections during preschool age.Methods: In the Danish population‐based COPSAC₂₀₁₀ mother–child cohort, information on 10 diet‐related vertically transferred metabolites from metabolomics profiles of dried blood spots (DBS) at age 2–3 days was analyzed in relation to the risk of childhood asthma, allergy, eczema, and infections using principal component and single metabolite analyses.Results: In 678 children with DBS measurements, a coffee‐related metabolite profile reflected by principal component 1 was inversely associated with risk of asthma (odds ratio (95% CI) 0.78 (0.64; 0.95), p = .014) and eczema at age 6 years (0.79 (0.65; 0.97), p = .022). Furthermore, increasing stachydrine (fruit‐related), 3‐carboxy‐4‐methyl‐5‐propyl‐2‐furanpropanoate (fish‐related), and ergothioneine (fruit‐, green vegetables‐, and fish‐related) levels were all significantly associated with reduced risks of infections at age 0–3 years (p < .05).Conclusion: This study demonstrates associations between pregnancy diet‐related vertically transferred metabolites measured in children in early life and risk of atopic diseases and infections in childhood. The specific metabolites associated with a reduced disease risk in children may contribute to the characterization of a healthy nutritional profile in pregnancy using a metabolomics‐based unbiased tool for predicting childhood health.