The role that vitamin D plays in pulmonary function remains uncertain. Epidemiological studies reported mixed findings for serum 25-hydroxyvitamin D (25(OH)D)–pulmonary function association. We conducted the largest cross-sectional meta-analysis of the 25(OH)D–pulmonary function association to date, based on nine European ancestry (EA) cohorts (n 22 838) and five African ancestry (AA) cohorts (n 4290) in the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium. Data were analysed using linear models by cohort and ancestry. Effect modification by smoking status (current/former/never) was tested. Results were combined using fixed-effects meta-analysis. Mean serum 25(OH)D was 68 (sd 29) nmol/l for EA and 49 (sd 21) nmol/l for AA. For each 1 nmol/l higher 25(OH)D, forced expiratory volume in the 1st second (FEV1) was higher by 1·1 ml in EA (95 % CI 0·9, 1·3; P<0·0001) and 1·8 ml (95 % CI 1·1, 2·5; P<0·0001) in AA (Prace difference=0·06), and forced vital capacity (FVC) was higher by 1·3 ml in EA (95 % CI 1·0, 1·6; P<0·0001) and 1·5 ml (95 % CI 0·8, 2·3; P=0·0001) in AA (Prace difference=0·56). Among EA, the 25(OH)D–FVC association was stronger in smokers: per 1 nmol/l higher 25(OH)D, FVC was higher by 1·7 ml (95 % CI 1·1, 2·3) for current smokers and 1·7 ml (95 % CI 1·2, 2·1) for former smokers, compared with 0·8 ml (95 % CI 0·4, 1·2) for never smokers. In summary, the 25(OH)D associations with FEV1 and FVC were positive in both ancestries. In EA, a stronger association was observed for smokers compared with never smokers, which supports the importance of vitamin D in vulnerable populations.

Lutein, a fat-soluble carotenoid with antioxidant properties, may have an effect on respiratory health. However, the evidence is inconsistent. We aimed to cross-sectionally investigate the association between lutein intake and lung function by measuring forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC% in adults (aged 45–79 years). We included 4402 participants from the Rotterdam Study, a prospective cohort study in The Netherlands. Lutein intake was assessed using a validated FFQ. Lung function was assessed using spirometry around the same time point as the dietary assessment. No independent association was found between lutein intake and FEV1 (−12·17 (95 % CI −34·21, 9·87) ml per sd increase in lutein) after adjustment for age, sex, height, cohort effect, ethnicity, education, weight, total daily energy intake, smoking status, physical activity, and intakes of fatty acids, dietary fibre, alcohol, β-carotene, β-crypotoxanthin, lycopene and zeaxanthin. There was also no association between lutein and FVC or FEV1/FVC%. However, after stratification by smoking status, lutein intake was significantly associated with lower FEV1/FVC% in current smokers (−1·69 (95 % CI −2·93, −0·45) % per sd increase of lutein) independent of other carotenoids. The present study does not support an independent association between lutein intake and lung function in adults. However, future studies should focus on the potential inverse association between high lutein intake and lung function in specific risk groups such as smokers.

Approximately half of the variation in wellbeing measures overlaps with variation in personality traits. Studies of non-human primate pedigrees and human twins suggest that this is due to common genetic influences. We tested whether personality polygenic scores for the NEO Five-Factor Inventory (NEO-FFI) domains and for item response theory (IRT) derived extraversion and neuroticism scores predict variance in wellbeing measures. Polygenic scores were based on published genome-wide association (GWA) results in over 17,000 individuals for the NEO-FFI and in over 63,000 for the IRT extraversion and neuroticism traits. The NEO-FFI polygenic scores were used to predict life satisfaction in 7 cohorts, positive affect in 12 cohorts, and general wellbeing in 1 cohort (maximal N = 46,508). Meta-analysis of these results showed no significant association between NEO-FFI personality polygenic scores and the wellbeing measures. IRT extraversion and neuroticism polygenic scores were used to predict life satisfaction and positive affect in almost 37,000 individuals from UK Biobank. Significant positive associations (effect sizes <0.05%) were observed between the extraversion polygenic score and wellbeing measures, and a negative association was observed between the polygenic neuroticism score and life satisfaction. Furthermore, using GWA data, genetic correlations of -0.49 and -0.55 were estimated between neuroticism with life satisfaction and positive affect, respectively. The moderate genetic correlation between neuroticism and wellbeing is in line with twin research showing that genetic influences on wellbeing are also shared with other independent personality domains.

Breast-feeding has been associated with later bone health, but results from previous studies are inconsistent. We examined the associations of breast-feeding patterns and timing of introduction of solids with bone mass at the age of 6 years in a prospective cohort study among 4919 children. We collected information about duration and exclusiveness of breast-feeding and timing of introduction of any solids with postnatal questionnaires. A total body dual-energy X-ray absorptiometry scan was performed at 6 years of age, and bone mineral density (BMD), bone mineral content (BMC), area-adjusted BMC (aBMC) and bone area (BA) were analysed. Compared with children who were ever breast-fed, those never breast-fed had lower BMD (−4·62 mg/cm2; 95 % CI −8·28, −0·97), BMC (−8·08 g; 95 % CI −12·45, −3·71) and BA (−7·03 cm2; 95 % CI −12·55, −1·52) at 6 years of age. Among all breast-fed children, those who were breast-fed non-exclusively in the first 4 months had higher BMD (2·91 mg/cm2; 95 % CI 0·41, 5·41) and aBMC (3·97 g; 95 % CI 1·30, 6·64) and lower BA (−4·45 cm2; 95 % CI −8·28, −0·61) compared with children breast-fed exclusively for at least 4 months. Compared with introduction of solids between 4 and 5 months, introduction <4 months was associated with higher BMD and aBMC, whereas introduction between 5 and 6 months was associated with lower aBMC and higher BA. Additional adjustment for infant vitamin D supplementation did not change the results. In conclusion, results from the present study suggest that ever breast-feeding compared with never breast-feeding is associated with higher bone mass in 6-year-old children, but exclusive breast-feeding for 4 months or longer was not positively associated with bone outcomes.

Previous studies have suggested that prenatal maternal folate deficiency is associated with reduced prenatal brain growth and psychological problems in offspring. However, little is known about the longer-term impact. The aims of this study were to investigate whether prenatal maternal folate insufficiency, high total homocysteine levels and low vitamin B12 levels are associated with altered brain morphology, cognitive and/or psychological problems in school-aged children. This study was embedded in Generation R, a prospective population-based cohort study. The study sample consisted of 256 Dutch children aged between 6 and 8 years from whom structural brain scans were collected using MRI. The mothers of sixty-two children had insufficient (<8 nmol/l) plasma folate concentrations in early pregnancy. Cognitive development was assessed by the Snijders-Oomen Niet-verbale intelligentietest – Revisie and the NEPSY-II-NL. Psychological problems were assessed at age 6 years using the parent report of the Child Behavior Checklist. Low prenatal folate levels were associated with a smaller total brain volume (B –33·34; 95 % CI –66·7, 0·02; P=050) and predicted poorer performance on the language (B –0·28; 95 % CI –0·52, –0·04; P=0·020) and visuo-spatial domains (B –0·27; 95 % CI –0·50, –0·04; P=0·021). High homocysteine levels (>9·1 µmol/l) predicted poorer performance on the language (B –0·31; 95 % CI –0·56, –0·06; P=0·014) and visuo-spatial domains (B –0·36; 95 % CI –0·60, –0·11; P=0·004). No associations with psychological problems were found. Our findings suggest that folate insufficiency in early pregnancy has a long-lasting, global effect on brain development and is, together with homocysteine levels, associated with poorer cognitive performance.

Lutein is a carotenoid with strong antioxidant properties. Previous studies in adults suggest a beneficial role of lutein on cardiometabolic health. However, it is unknown whether this relation also exists in children; therefore, we aimed to assess the relation between lutein intake at 13 months of age and cardiometabolic outcomes at the age of 6 years. We included 2044 Dutch children participating in a population-based prospective cohort study. Diet was measured at 13 months of age with an FFQ. Lutein intake was standardised for energy and β-carotene intake. Blood pressure, anthropometrics, serum lipids and insulin were measured at the age of 6 years. Dual-energy X-ray absorptiometry was performed to measure total and regional fat and lean mass. A continuous cardiometabolic risk factor score was created, including the components body fat percentage, blood pressure, insulin, HDL-cholesterol and TAG. Age- and sex-specific standard deviation scores were created for all outcomes. Multivariable linear regression was performed, including socio-demographic and lifestyle variables. Median (energy-standardised) lutein intake was 1317 mcg/d (95 % range 87, 6069 mcg/d). There were no consistent associations between lutein intake at 13 months and anthropometrics and body composition measures at 6 years of age. In addition, lutein intake was not associated with a continuous cardiometabolic risk factor score, nor was it associated with any of the individual components of the cardiometabolic risk factor score. Results from this large population-based prospective cohort study do not support the hypothesis that lutein intake early in life has a beneficial role for later cardiometabolic health.

A vast body of literature shows that maternal depression has long-term adverse consequences for children. However, only very few studies have documented the effect of maternal depression on children's ability to process emotional expressions and even fewer incorporated measures of observed maternal sensitivity to further tease apart whether it is the symptoms per se or the associated impact via maternal sensitivity that affects children's developing emotion-processing abilities. In a large community sample of Dutch preschoolers (N = 770), we examined independent and mediated effects of maternal depressive symptoms and sensitivity on children's ability to recognize emotional expressions using a nonverbal and a verbal task paradigm. Maternal depressive symptoms predicted less accurate emotion labeling in children, while maternal sensitivity was associated with more accurate emotion matching, especially for sadness and anger. Maternal sensitivity did not mediate the observed associations between mothers’ depressive symptoms and children's emotion recognition, and effects were similar for boys and girls. Given that maternal depressive symptoms and sensitivity affected nonoverlapping areas of young children's emotion recognition, prevention and intervention efforts should focus on both alleviating maternal depressive symptoms and improving maternal sensitivity at the same time in order to maximize benefit.

Suboptimal maternal dietary intake during pregnancy might lead to fetal cardiovascular adaptations and higher blood pressure in the offspring. The aim of the present study was to investigate the associations of maternal first-trimester dietary intake with blood pressure in children at the age of 6 years. We assessed first-trimester maternal daily dietary intake by a FFQ and measured folate, homocysteine and vitamin B12 concentrations in the blood, in a population-based prospective cohort study among 2863 mothers and children. Childhood systolic and diastolic blood pressure was measured using a validated automatic sphygmomanometer. First-trimester maternal daily intake of energy, fat, protein and carbohydrate was not associated with childhood blood pressure. Furthermore, maternal intake of micronutrients was not associated with childhood blood pressure. Also, higher maternal vitamin B12 concentrations were associated with a higher diastolic blood pressure (0·31 mmHg per standard deviation increase in vitamin B12 (95 % CI 0·06, 0·56)). After taking into account multiple testing, none of the associations was statistically significant. Maternal first-trimester folate and homocysteine concentrations were not associated with childhood blood pressure. The results from the present study suggest that maternal Fe intake and vitamin B12 concentrations during the first trimester of pregnancy might affect childhood blood pressure, although the effect estimates were small and were not significant after correction for multiple testing. Further studies are needed to replicate these findings, to elucidate the underlying mechanisms and to assess whether these differences in blood pressure persist in later life.

We studied the association, and its direction, between the introduction of solids and weight-for-height (WFH) change between birth and 45 months. Pregnant women were asked to participate in a birth cohort during their first antenatal visit. Data from 3184 children were used. The timing of the introduction of solids was reported by the mother from a questionnaire at 12 months postpartum, and categorised into very early (0–3 months), early (3–6 months) and timely (after 6 months) introduction of solids. Anthropometric data were collected during standardised child health centre visits. WFH was converted into a z-score. Repeated-measurements analyses with splines positioned according to the moments of solid introduction were used to obtain estimates for WFH change before and after the introduction of solids. Analyses were adjusted for educational level, ethnicity, smoking during pregnancy, mother's BMI, breast-feeding, history of food allergy and infant's hospital admission. Before solids were introduced, weight gain was higher in children introduced to solids early (z= 0·65, 95 % CI 0·34, 0·95) than in children introduced to solids very early (z= 0·02, 95 % CI − 0·03, 0·08) and timely (z= − 0·04, 95 % CI − 0·05, − 0·03). Shortly after the introduction of solids, children introduced to solids very early and early showed a relative decrease in WFH. WFH change did not differ between the solid introduction groups after 12 months, and at that time, weight change was as expected (i.e. z= 0). We therefore conclude that differences in WFH in childhood are not the result of early introduction to solids.

Determinants of a child's diet shortly after weaning and lactation have been relatively understudied. The aim of the present study was hence to identify common dietary patterns in toddlers and to explore parental and child indicators of these dietary patterns. The study was a population-based, prospective birth-cohort study in Rotterdam, the Netherlands. Food consumption data of 2420 children aged 14 months were used. A ‘Health conscious’ dietary pattern characterised by pasta, fruits, vegetables, oils, legumes and fish, and a ‘Western-like’ dietary pattern characterised by snacks, animal fats, confectionery and sugar-containing beverages were extracted using principal component analysis. Low paternal education, low household income, parental smoking, multiparity, maternal BMI, maternal carbohydrate intake and television-watching of child were determinants of a ‘Western-like’ diet, whereas parental age, dietary fibre intake during pregnancy, introduction of solids after 6 months and female sex were inversely associated with a ‘Western-like’ diet of the child. Maternal co-morbidity, alcohol consumption during pregnancy and female sex were inversely associated with a ‘Health conscious’ dietary pattern of the child, while single parenthood, folic acid use and dietary fibre intake during pregnancy were positively associated. All aforementioned associations were statistically significant. In conclusion, both ‘Western-like’ and ‘Health conscious’ diets can already be identified in toddlers. Particularly, adherence to a ‘Western-like’ diet is associated with unfavourable lifestyle factors of the parents and child, and low socio-economic background. These findings can form a basis for future epidemiological studies regarding dietary patterns and health outcomes in young children.

Developmental adaptations due to early nutritional exposures may have permanent health consequences. Studies of diet and fetal size have mainly focused on individual nutrients despite evidence that the pattern of food consumption may be of significance. Hence, we evaluated the associations of dietary habits in early pregnancy (gestational age < 18 weeks) with fetal size, uteroplacental vascular resistance, placental weight and birth weight in a prospective observational study of 3207 Caucasian pregnant mothers in Rotterdam, the Netherlands. Participants completed a semiquantitative FFQ during early pregnancy. Logistic regression analysis was used to predict the occurrence of intra-uterine growth retardation at birth as a function of food intake. The derived solution was considered as the dietary pattern. As it was characterised by higher intakes of fruit, vegetables, vegetable oil, fish, pasta and rice, and lower intakes of meat, potatoes and fatty sauces, it was labelled the ‘Mediterranean’ diet. The degree of adherence to the diet was positively associated with plasma folate and serum vitamin B12 concentrations and showed an inverse relationship with homocysteine and high-sensitivity C-reactive protein plasma concentrations (P <0·05). Important fetal size and placental parameters were associated with the degree of adherence to the diet, revealing a 72 g lower birth weight (95 % CI − 110·8, − 33·3) and a 15 g lower placental weight (95 % CI − 29·8, − 0·2) for women with low adherence to the diet. To conclude, low adherence to a Mediterranean diet in early pregnancy seems associated with decreased intra-uterine size with a lower placental and a lower birth weight.

Breast-feeding has been suggested to be associated with lower risks of obesity in older children and adults. We assessed whether the duration and exclusiveness of breast-feeding are associated with early postnatal growth rates and the risks of overweight and obesity in preschool children. The present study was embedded in a population-based prospective cohort study from early fetal life onwards, among 5047 children and their mothers in The Netherlands. Compared with children who were breast-fed, those who were never breast-fed had a lower weight at birth (difference 134 (95 % CI − 190, − 77) g). No associations between breast-feeding duration and exclusivity with growth rates before the age of 3 months were observed. Shorter breast-feeding duration was associated with an increased gain in age- and sex-adjusted standard deviation scores for length, weight and BMI (P for trend < 0·05) between 3 and 6 months of age. Similar tendencies were observed for the associations of breast-feeding exclusivity with change in length, weight and BMI. Breast-feeding duration and exclusivity were not consistently associated with the risks of overweight and obesity at the ages of 1, 2 and 3 years. In conclusion, shorter breast-feeding duration and exclusivity during the first 6 months tended to be associated with increased growth rates for length, weight and BMI between the age of 3 and 6 months but not with the risks of overweight and obesity until the age of 3 years.

Maternal fish consumption during pregnancy has been suggested to affect birth outcomes. Previous studies mainly focused on birth outcomes and did not study fetal growth during pregnancy. In a prospective cohort study from early pregnancy onwards in The Netherlands, we assessed the associations of first-trimester maternal total-fish, lean-fish, fatty-fish and shellfish consumption with fetal growth characteristics in the second and third trimesters, growth characteristics at birth and the risks of neonatal complications, including pre-term birth, low birth weight and small for gestational age. In total, 3380 mothers completed a 293-item semi-quantitative FFQ to obtain information about fish consumption during the first trimester of pregnancy. Head circumference, femur length and fetal weight were estimated in the second and third trimesters by ultrasound. Information about birth anthropometrics and neonatal complications was available from hospital and midwife registries. Maternal older age, higher educational level, folic acid supplement use, alcohol use and not smoking were associated with higher fish consumption (P < 0·01). After adjustment, we observed no consistent associations of maternal total-fish consumption or specific consumption of lean fish, fatty fish or shellfish with fetal growth characteristics in the second and third trimesters and at birth. Likewise, total-fish consumption or specific consumption of any type of fish was not consistently associated with the risks of neonatal complications. These findings suggest that in a population with a relatively low fish intake, consumption of lean fish, fatty fish or shellfish in the first trimester is not associated with fetal growth or the risks of neonatal complications.

Folate deficiency during embryogenesis is an established risk factor for neural tube defects in the fetus. An adequate folate nutritional status is also important for normal fetal growth and brain development. The aim of the present research was to study the association between folic acid use of the mother during pregnancy and child behavioural development. Within a population-based cohort, we prospectively assessed folic acid supplement use during the first trimester by questionnaire. Child behavioural and emotional problems were assessed with the Child Behaviour Checklist at the age of 18 months in 4214 toddlers. Results showed that children of mothers who did not use folic acid supplements in the first trimester had a higher risk of total problems (OR 1·44; 95 % CI 1·12, 1·86). Folic acid supplement use protected both from internalising (OR of no supplement use 1·65; 95 % CI 1·24, 2·19) and externalising problems (OR 1·45; 95 % CI 1·17, 1·80), even when adjusted for maternal characteristics. Birth weight and size of the fetal head did not mediate the association between folic acid use and child behaviour. In conclusion, inadequate use of folic acid supplements during early pregnancy may be associated with a higher risk of behavioural problems in the offspring. Folic acid supplementation in early pregnancy, aimed to prevent neural tube defects, may also reduce mental health problems in children.

Countries worldwide, including the Netherlands, recommend that women planning pregnancy use a folic acid supplement during the periconception period. Some countries even fortify staple foods with folic acid. These recommendations mainly focus on the prevention of neural tube defects, despite increasing evidence that folic acid may also influence birth weight. We examined whether periconception folic acid supplementation affects fetal growth and the risks of low birth weight, small for gestational age (SGA) and preterm birth, in the Generation R Study in Rotterdam, the Netherlands. Main outcome measures were fetal growth measured in mid- and late pregnancy by ultrasound, birth weight, SGA and preterm birth in relation to periconception folic supplementation (0·4–0·5 mg). Data on 6353 pregnancies were available. Periconception folic acid supplementation was positively associated with fetal growth. Preconception folic acid supplementation was associated with 68 g higher birth weight (95 % CI 37·2, 99·0) and 13 g higher placental weight (95 % CI 1·1, 25·5), compared to no folic acid supplementation. In these analyses parity significantly modified the effect estimates. Start of folic acid supplementation after pregnancy confirmation was associated with a reduced risk of low birth weight (OR 0·61, 95 % CI 0·40, 0·94). Similarly, reduced risks for low birth weight and SGA were observed for women who started supplementation preconceptionally, compared to those who did not use folic acid (OR 0·43, 95 % CI 0·28, 0·69 and OR 0·40, 95 % CI 0·22, 0·72). In conclusion, periconception folic acid supplementation is associated with increased fetal growth resulting in higher placental and birth weight, and decreased risks of low birth weight and SGA.

Background: Ommoord District residents of Rotterdam, The Netherlands, age 55 and older, completed a two-stage interview to assess the risk factors for chronic disease and disability. Methods: In the in-home Stage I interview (N = 7,983), demographic data and medical history were collected by a trained lay interviewer. During Stage II, a physician interview and examination were conducted at the study center. Subjects (N = 7,129) were asked about their history of psychiatric disorders and 6,596 responded. Results: The lifetime prevalence of self-reported psychiatric disorders was 5.44% for unipolar and bipolar depressive disorders combined, 0.27% for psychotic disorders, 0.08% for alcoholism, 0.05% for drug addiction, and 3.71% for other diagnoses. Residents reporting a psychiatric diagnosis of depression were more likely to be currently taking an antidepressant medication (p < .001) and an antipsychotic medication (p < .0001), to be in current outpatient treatment (p < .001), to have been hospitalized for psychiatric illness (p < .001), to have undergone electroconvulsive treatments (p < .001), and to report a history of having made suicide attempts (p < .001). Conclusion: The self-reported lifetime prevalence of affective disorders was similar to the rates found in the Stirling County Study (Canada) and the Epidemiologic Catchment Area Survey (United States). The lower prevalence rates of the other psychiatric disorders may reflect underreporting or an age cohort effect, or may be due to the nonresponse bias.