Lars Libuda

Vitamin D and mental health in children and adolescents

While vitamin D is known to be relevant for bone health, evidence has recently accumulated for an impact on mental health. To identify the potential benefits and limitations of vitamin D for mental health, an understanding of the physiology of vitamin D, the cut-off values for vitamin D deficiency and the current status of therapeutic trials is paramount. Results of a systematic PUBMED search highlight the association of vitamin D levels and mental health conditions. Here, we focus on children and adolescents studies as well as randomized controlled trials on depression in adults. 41 child and adolescent studies were identified including only 1 randomized controlled and 7 non-controlled supplementation trials. Overall, results from 25 cross-sectional studies as well as from 8 longitudinal studies suggest a role of vitamin D in the pathogenesis of mental disorders in childhood and adolescence. Findings from supplementation trials seem to support this hypothesis. However, randomized controlled trials in adults revealed conflicting results. Randomized controlled trials in childhood and adolescents are urgently needed to support the potential of vitamin D as a complementary therapeutic option in mental disorders. Study designs should consider methodological challenges, e.g., hypovitaminosis D at baseline, appropriate supplementation doses, sufficient intervention periods, an adequate power, clinically validated diagnostic instruments, and homogenous, well-defined risk groups.

Changes in water and sugar-containing beverage consumption and body weight outcomes in children

An intervention study showed that promoting water consumption in schoolchildren prevented overweight, but a mechanism linking water consumption to overweight was not substantiated. We investigated whether increased water consumption replaced sugar-containing beverages and whether changes in water or sugar-containing beverages influenced body weight outcomes. In a secondary analysis of the intervention study in Germany, we analysed combined longitudinal data from the intervention and control groups. Body weight and height were measured and beverage consumption was self-reported by a 24-h recall questionnaire at the beginning and end of the school year 2006/2007. The effect of a change in water consumption on change in sugar-containing beverage (soft drinks and juices) consumption, change in BMI (kg/m2) and prevalence of overweight and obesity at follow-up was analysed using regression analyses. Of 3220 enroled children, 1987 children (mean age 8·3 (sd 0·7) years) from thirty-two schools were analysed. Increased water consumption by 1 glass/d was associated with a reduced consumption of sugar-containing beverages by 0·12 glasses/d (95 % CI -0·16, -0·08) but was not associated with changes in BMI (P=0·63). Increased consumption of sugar-containing beverages by 1 glass/d was associated with an increased BMI by 0·02 (95 % CI 0·00, 0·03) kg/m2 and increased prevalence of obesity (OR 1·22; 95 % CI 1·04, 1·44) but not with overweight (P=0·83). In conclusion, an increase in water consumption can replace sugar-containing beverages. As sugar-containing beverages were associated with weight gain, this replacement might explain the prevention of obesity through the promotion of water consumption.

Low 25(OH)-vitamin D concentrations are associated with emotional and behavioral problems in German children and adolescents

Background Evidence has accumulated for the association between low vitamin D serum concentrations and mental health disorders in both children and adults. We performed a cross-sectional analysis in a population-based sample of children and adolescents to detect associations between 25(OH)-vitamin D serum [25(OH)D] concentrations and scores of the five Strengths and Difficulties Questionnaire (SDQ) subscales and the total difficulties score in different age groups (age ≥3-<12 years and ≥12-<18 years). Methods 9068 participants of the population-based, nation-wide German Health Interview and Examination Survey for Children and Adolescents (KIGGS) with information on mental health status assessed by the SDQ and 25(OH)D levels were included in the analysis. For statistical analysis we used linear regression models stratified by gender based on different adjustment sets. For the younger subsample the analysis was additionally adjusted for the frequency of playing outside. We compared the associations based on parent- and self-ratings of the SDQ for children and adolescents aged ≥12-<18 years. Results We found inverse associations between 25(OH)D concentrations and the subscales emotional problems, peer relationship problems and the total difficulties score in both genders after adjustment for potential confounders. The strongest associations were observed in the older subsample for parent-ratings in boys and self-ratings in girls. In the younger subsample the associations were less strong and no longer evident after adjustment for potential confounders such as migration background, socioeconomic status and frequency of playing outside. Conclusion Based on the large-scale cross-sectional study in a German population-based sample of children and adolescents we detected inverse associations between 25(OH)D concentrations and both parent- and self-rated SDQ scores of the total difficulties scale and different subscales with the strongest association in the subsample aged ≥12-<18 years for both genders. Migration background and socioeconomic status were detected as relevant confounders. Further studies–particularly in countries with comparatively low mean 25(OH)D concentrations–in childhood and adolescence are warranted. Longitudinal studies are also necessary to infer direction of effects. Finally, RCTs in children and adolescents are required to determine whether Vitamin D is beneficial for mental health.

The role of genetic variation of human metabolism for BMI, mental traits and mental disorders.

Objective The aim was to assess whether loci associated with metabolic traits also have a significant role in BMI and mental traits/disorders Methods We first assessed the number of single nucleotide polymorphisms (SNPs) with genome-wide significance for human metabolism (NHGRI-EBI Catalog). These 516 SNPs (216 independent loci) were looked-up in genome-wide association studies for association with body mass index (BMI) and the mental traits/disorders educational attainment, neuroticism, schizophrenia, well-being, anxiety, depressive symptoms, major depressive disorder, autism-spectrum disorder, attention-deficit/hyperactivity disorder, Alzheimers disease, bipolar disorder, aggressive behavior, and internalizing problems. A strict significance threshold of p < 6.92 × 10−6 was based on the correction for 516 SNPs and all 14 phenotypes, a second less conservative threshold (p < 9.69 × 10−5) on the correction for the 516 SNPs only. Results 19 SNPs located in nine independent loci revealed p-values < 6.92 × 10−6; the less strict criterion was met by 41 SNPs in 24 independent loci. BMI and schizophrenia showed the most pronounced genetic overlap with human metabolism with three loci each meeting the strict significance threshold. Overall, genetic variation associated with estimated glomerular filtration rate showed up frequently; single metabolite SNPs were associated with more than one phenotype. Replications in independent samples were obtained for BMI and educational attainment. Conclusions Approximately 5–10% of the regions involved in the regulation of blood/urine metabolite levels seem to also play a role in BMI and mental traits/disorders and related phenotypes. If validated in metabolomic studies of the respective phenotypes, the associated blood/urine metabolites may enable novel preventive and therapeutic strategies.

Sedentary Behavior Is Independently Related to Fat Mass among Children and Adolescents in South China

We aim to explore the independent associations of sedentary behaviors (SB) with body mass distribution among Chinese children. Data on the screen-based sedentary time (television viewing and computer use) and doing homework, physical activities and dietary intake of 1586 Chinese children (50.3% girls) aged 7–15 years were obtained through validated questionnaires. Skin-fold thickness, body height, and weight were measured to calculate percent body fat (%BF), fat mass index (FMI), and fat-free mass index (FFMI). Parental characteristics were collected by questionnaires. Among girls, time of SB (screen time or doing homework) was positively related to %BF, FMI, and FFMI (p < 0.03) after adjusting for maternal overweight, the average annual income of family, moderate-to-vigorous physical activity energy expenditure, and energy intake: Girls in the highest tertile of screen time/homework had 16.7%/23.3% higher relative FMI and 2.9%/2.9% higher relative FFMI than girls in the lowest tertile. Among boys, screen time was positively associated with FFMI (p < 0.003), but not related to %BF and FMI (p > 0.09), while time of doing homework was positively related to %BF and FMI (p = 0.03). Sedentary behaviors might be positively and independently related to fat mass among Chinese children, and were more pronounced in girls.

Dietary Acid Load and Mental Health Outcomes in Children and Adolescents: Results from the GINIplus and LISA Birth Cohort Studies

High dietary acid load may have detrimental effects on mental health during childhood and adolescence. We examined cross-sectional and prospective associations of dietary acid load and mental health problems in a population-based sample, using data from the German birth cohort studies GINIplus (German Infant Nutritional Intervention plus environmental and genetic influences on allergy development) and LISA (Influences of lifestyle-related factors on the immune system and the development of allergies in childhood). These studies included detailed assessments of dietary intake through a food frequency questionnaire (FFQ), mental health outcomes measured through the Strengths and Difficulties Questionnaire (SDQ), and covariates. Using logistic regression, cross-sectional associations between dietary acid load measured as potential renal acid load (PRAL) and SDQ subscales were assessed at age 10 years (N = 2350) and 15 years (N = 2061). Prospective associations were assessed, considering PRAL at 10 years as exposure and SDQ subscales at 15 years as outcome (N = 1685). Results indicate that children with a diet higher in PRAL have more emotional problems (OR = 1.33 (95% CI = 1.15; 1.54); p < 0.001), and show hyperactivity more often (1.22 (1.04; 1.43); p = 0.014) at 10 years. No significant associations were present either cross-sectionally at age 15 years, nor prospectively. Results were confirmed in sensitivity analyses. These findings reveal first evidence for potential relationships between PRAL and mental health in childhood, although we cannot exclude reverse causality, i.e., that dietary behavior and PRAL are influenced by mental status. Future studies should address confirmation and identify biological mechanisms.