Vitamin D and depression in older adults: lessons learned from observational and clinical studies.

Depression is a mental disorder triggered by the interaction of social, psychological and biological factors that have an important impact on an individual's life. Despite being a well-studied disease with several established forms of treatment, its prevalence is increasing, especially among older adults. New forms of treatment and prevention are encouraged, and some researchers have been discussing the effects of vitamin D (VitD) on depression; however, the exact mechanism by which VitD exerts its effects is not yet conclusive. In this study, we aimed to discuss the possible mechanisms underlying the association between VitD and depression in older adults. Therefore, we conducted a systematic search of databases for indexed articles published until 30 April 2021. The primary focus was on both observational studies documenting the association between VitD and depression/depressive symptoms, and clinical trials documenting the effects of VitD supplementation on depression/depressive symptoms, especially in older adults. Based on pre-clinical, clinical and observational studies, it is suggested that the maintenance of adequate VitD concentrations is an important issue, especially in older adults, which are a risk population for both VitD deficiency and depression. Nevertheless, it is necessary to carry out more studies using longitudinal approaches in low- and middle-income countries to develop a strong source of evidence to formulate guidelines and interventions.

Effects of nutritional interventions on the severity of depressive and anxiety symptoms of women in the menopausal transition and menopause: a systematic review, meta-analysis, and meta-regression.

IMPORTANCE: Depression and anxiety may significantly affect women during the menopausal transition. In addition to traditional treatment strategies such as hormone therapy, antidepressants, and psychotherapy, nutritional interventions have been increasingly studied, but there is no consensus about their role in this patient population. OBJECTIVE: This systematic review and meta-analysis aimed to evaluate the effect of nutritional interventions on the severity of depressive (DS) and anxiety (AS) symptoms in women during the menopausal transition or menopausal years. EVIDENCE REVIEW: Electronic search using databases PubMed, Cochrane, and Embase to identify articles indexed until January 31, 2021, focusing on randomized placebo-controlled trials documenting the effect of diet, food supplements, and nutraceuticals on DS and AS. FINDINGS: Thirty-two studies were included (DS, n = 15; AS, n = 1; DS and AS combined, n = 16). We found two studies that demonstrated data combined with other interventions: one with lifestyle interventions (vitamin D plus lifestyle-based weight-loss program) and another with exercise (omega 3 plus exercise). The pooled effect size favored the intervention group over placebo for both DS and AS (DS: standardized mean difference, -0.35 [95% confidence interval, -0.68 to -0.03; P = 0.0351]; AS: standardized mean difference, -0.74 [95% CI, -1.37 to -0.11; P = 0.0229]). There was significant heterogeneity in the pooled results, which can be attributed to differences in assessment tools for depression and anxiety as well as the variety of nutritional interventions studied. The subgroup analysis showed a statistically significant effect of menopausal status (perimenopausal or menopausal) but not the type or duration of nutritional intervention. Older age was the only significant predictor of the effect size of nutritional interventions in the meta-regression. CONCLUSIONS AND RELEVANCE: Nutritional interventions are promising tools for the management of mood/anxiety symptoms in women during the menopausal transition and in postmenopausal years. Because of significant heterogeneity and risk of bias among studies, the actual effect of different approaches is still unclear.

Vitamin D, Depressive Symptoms, and Covid-19 Pandemic.

Since the COVID-19 outbreak, studies across diverse countries have strongly pointed toward the emergence of a mental health crisis, with a dramatic increase in the prevalence of depressive psychopathology and suicidal tendencies. Vitamin D deficiency has been associated with an increased risk of mental health problems as well as individual responses to stress. Studies have discussed the relationship between low serum vitamin D concentrations and depressive symptoms, suggesting that maintaining adequate concentrations of serum vitamin D seems to have a protective effect against it. Vitamin D was found to contribute to improved serotonergic neurotransmission in the experimental model of depression by regulating serotonin metabolism. The signaling of 1,25-dihydroxyvitamin D3, the active form of vitamin D, through vitamin D receptor (VDR) induces the expression of the gene of tryptophan hydroxylase 2 (TPH2), influences the expression of serotonin reuptake transporter (SERT) as well as the levels of monoamine oxidase-A (MAO-A), the enzyme responsible for serotonin catabolism. Vitamin D also presents a relevant link with chronobiological interplay, which could influence the development of depressive symptoms when unbalance between light-dark cycles occurs. In this Perspective, we discussed the significant role of vitamin D in the elevation of stress-related depressive symptoms during the COVID-19 pandemic. It is suggested that vitamin D monitoring and, when deficiency is detected, supplementation could be considered as an important healthcare measure while lockdown and social isolation procedures last during the COVID-19 pandemic.