The Influence of Vitamin D Intake and Status on Mental Health in Children: A Systematic Review

Nutrients

Mar 2021

DOI: 10.3390/nu13030952

Citations:50

Influential Citations:1

Systematic Reviews / Meta-Analyses

Enhanced Details

Methods

Interventional designs included randomized, double-blind, placebo-controlled trials and some open-label/longitudinal studies. Participants were children and adolescents roughly 4–20 years old, including healthy controls and those with sickle cell disease, ADHD, autism spectrum disorders, bipolar spectrum disorders, or depression, across the United States, Iran, Norway, Sweden, Turkey and other locations; both sexes were included.

Intervention

Vitamin D supplementation regimens varied across trials and included oral vitamin D3 (cholecalciferol) or vitamin D2 (ergocalciferol). Daily doses ranged from 25 µg/day to 100 µg/day (with arms at 50 µg/day or 175 µg/day), and weekly doses reached up to 1250 µg/week (≈179 µg/day). Some regimens were adjusted by baseline 25(OH)D status (e.g., 50–72.5 nmol/L receiving 50 µg/day vs <50 nmol/L receiving 1250 µg/week). Durations were typically 2–3 months (e.g., 8 weeks, 9 weeks, or 3 months). Administration was oral; some trials used placebo controls while others were open-label or observational extensions.

Results

Most studies, especially those with low risk of bias, indicate a beneficial association between vitamin D status or supplementation and mental health outcomes in children, including reductions in depressive symptoms, fatigue, anxiety, sleep disturbances, and improvements in quality of life and well-being. Some studies found no effect for bipolar disorder or major depressive disorder, and a few analyses were inconclusive for obsessive–compulsive disorder or aggression. The overall interpretation is that meeting adequate 25(OH)D levels through diet, supplementation, or safe sun exposure supports child mental health; further robust randomized trials are needed to strengthen causality.

Limitations

Limited number of studies; substantial heterogeneity in populations, outcomes, and psychological measures; variability in vitamin D forms, doses, and durations; many studies were nonrandomized or observational; meta-analysis was not feasible; potential reverse causality in observational data; search limited to PubMed/Web of Science up to October 2019.

Abstract

A potential role of vitamin D in some components of mental health is currently suggested, but the analyses are conducted mainly for adults, while for young individuals mental health is especially important, due to its lifelong effects. The aim of the study was to analyze the association between vitamin D intake or status and mental health in children within a systematic review of literature, including both intervention and observational studies. The literature search was conducted according to the PRISMA guidelines and it covered peer-reviewed studies included in databases of PubMed and Web of Science until October 2019. The studies presenting either vitamin D intake, or vitamin D status in human subjects were allowed (excluding subjects with intellectual disabilities, eating disorders and neurological disorders), while for mental health the various methods of assessment and wide scope of factors were included. The bias was assessed using the Newcastle–Ottawa Scale (NOS). The review was registered in the PROSPERO database (CRD42020155779). A number of 7613 studies after duplicate removing were extracted by two independent researchers, followed by screening and assessment for eligibility, conducted by two independent researchers in two steps (based on title and abstract). Afterwards, the full texts were obtained and after reviewing, a number of 24 studies were included. The synthetic description of the results was prepared, structured around exposure (vitamin D supplementation/status) and outcome (components of mental health). The included studies were conducted either in groups of healthy individuals, or individuals with mental health problems, and they assessed following issues: behavior problems, violence behaviors, anxiety, depressive symptoms/depression, aggressive disorder, psychotic features, bipolar disorder, obsessive compulsive disorder, suicidal incident, as well as general patterns, as follows: mental health, level of distress, quality of life, well-being, mood, sleep patterns. The vast majority of assessed studies, including the most prominent ones (based on the NOS score) supported potential positive influence of vitamin D on mental health in children. As a limitation of the analysis, it should be indicated that studies conducted so far presented various studied groups, outcomes and psychological measures, so more studies are necessary to facilitate comparisons and deepen the observations. Nevertheless, vitamin D intake within a properly balanced diet or as a supplementation, except for a safe sun exposure, should be indicated as an element supporting mental health in children, so it should be recommended to meet the required 25(OH)cholecalciferol blood level in order to prevent or alleviate mental health problems. show less