vitamina D e depressão

Effects of vitamin D supplementation on symptoms of depression in overweight and obese subjects: randomized double blind trial
R. Jorde 1,2 , M. Sneve 2 , Y. Figenschau 3,4 , J. Svartberg 1,2 & K. Waterloo 5,6
From the 1Institute of Clinical Medicine, University of Tromsø ; Departments of 2Internal Medicine and 3 Medical Biochemistry, University Hospital of North Norway ; 4 Institute of Medical Biology, University of Tromsø ; 5 Department of Neurology, University Hospital of North Norway ; and 6 Department of Psychology, University of Tromsø, Tromsø, Norway
Correspondence to Rolf Jorde, Medical Department, University Hospital of North Norway, Tromsø 9038, Norway.(fax: + 47 776 26863; e-mail: rolf.jorde@unn.no). J Intern Med 2008;
Objectives. The objective of the present study was to examine the cross-sectional relation between serum 25-hydoxyvitamin D [25-(OH) D] levels and depression in overweight and obese subjects and to assess the effect of vitamin D supplementation on depressive symptoms.
Design. Cross-sectional study and randomized double blind controlled trial of 20.000 or 40.000 IU vitamin D per week versus placebo for 1 year.
Setting. A total of 441 subjects (body mass index 28–47 kg m−2, 159 men and 282 women, aged 21–70 years) recruited by advertisements or from the out-patient clinic at the University Hospital of North Norway.
Main outcome measures. Beck Depression Inventory (BDI) score with subscales 1–13 and 14–21.
Results. Subjects with serum 25(OH)D levels <40 nmol L−1 scored significantly higher (more depressive traits) than those with serum 25(OH)D levels ≥40 nmol L−1 on the BDI total [6.0 (0–23) versus 4.5 (0–28) (median and range)] and the BDI subscale 1–13 [2.0 (0–15) versus 1.0 (0–29.5)] (P < 0.05). In the two groups given vitamin D, but not in the placebo group, there was a significant improvement in BDI scores after 1 year. There was a significant decrease in serum parathyroid hormone in the two vitamin D groups without a concomitant increase in serum calcium.
Conclusions. It appears to be a relation between serum levels of 25(OH)D and symptoms of depression. Supplementation with high doses of vitamin D seems to ameliorate these symptoms indicating a possible causal relationship.

Exercício, ansiedade e depressão

Testing Causality in the Association Between Regular Exercise and Symptoms of Anxiety and Depression
Marleen H. M. De Moor, MSc; Dorret I. Boomsma, PhD; Janine H. Stubbe; Gonneke Willemsen, PhD; Eco J. C. de Geus, PhD
Arch Gen Psychiatry. 2008;65(8):897-905.
Context In the population at large, regular exercise is associated with reduced anxious and depressive symptoms. Results of experimental studies in clinical populations suggest a causal effect of exercise on anxiety and depression, but it is unclear whether such a causal effect also drives the population association. We cannot exclude the major contribution of a third underlying factor influencing exercise behavior and symptoms of anxiety and depression.
Objective To test causal effects of exercise on anxious and depressive symptoms in a population-based sample.
Design Population-based longitudinal study (1991-2002) in a genetically informative sample of twin families.
Setting Causal effects of exercise were tested by bivariate genetic modeling of the association between exercise and symptoms of anxiety and depression, correlation of intrapair differences in these traits among genetically identical twins, and longitudinal modeling of changes in exercise behavior and anxious and depressive symptoms.
Participants A total of 5952 twins from the Netherlands Twin Register, 1357 additional siblings, and 1249 parents. All participants were aged 18 to 50 years.
Main Outcome Measurements Survey data about leisure-time exercise (metabolic equivalent task hours per week based on type, frequency, and duration of exercise) and 4 scales of anxious and depressive symptoms (depression, anxiety, somatic anxiety, and neuroticism, plus a composite score).
Results Cross-sectional and longitudinal associations were small and were best explained by common genetic factors with opposite effects on exercise behavior and symptoms of anxiety and depression. In genetically identical twin pairs, the twin who exercised more did not display fewer anxious and depressive symptoms than the co-twin who exercised less. Longitudinal analyses showed that increases in exercise participation did not predict decreases in anxious and depressive symptoms.
Conclusion Regular exercise is associated with reduced anxious and depressive symptoms in the population at large, but the association is not because of causal effects of exercise.