The main function of vitamin D is calcium homeostasis. However, emerging evidence has correlated adequate serum 25-hydroxyvitamin D (25(OH)D) concentrations with better mental health. The objective of this study is to investigate the association of serum 25(OH)D concentrations with indicators of mental health such as depression, anxiety, and stress. Associations of serum 25(OH)D concentrations with four indicators of mental health were examined using ordered logistic regression models with increasing specificity that account for demographics, socio-economic status, and health. Margin effects are used to determine the probability of the average adult Canadian being in the best mental health state by groupings of serum 25(OH)D concentrations. A robust association between serum 25(OH)D concentrations and the indicators of mental health were observed. In the fully adjusted ordered logistic model, an average Canadian appeared more likely to experience better mental health when serum 25(OH)D concentrations were higher. This study adds to the weight of the existence of an association between vitamin D status and mental health, but, as this study is cross sectional, it does not establish causality. Due to the low risk of harm from toxicity and the relative modest costs of vitamin D supplements, more research to establish the effectiveness and causality of this relationship is recommended.

This study explores the relationship between hospital costs and quality of care for Acute Myocardial Infarction (AMI) in the Edmonton area hospitals. The importance of this relationship is realized when policy makers face decisions about cost minimization and quality maximization during times of health care budget constraints. This study uses regression modelling with increasing specifications as well as various robustness checks to ensure the accuracy of the results. The Model specifications include demographics, AMI risk adjustments, Hospital fixed effects, and year fixed effects. Semi-parametric regression removes the assumption of linearity to determine the true relationship between hospital cost and AMI quality. Higher AMI quality is associated with a 39% increase in hospital costs after adjustments and controls. The semi-parametric regression shows a fairly linear relationship between cost and AMI quality. This study suggests that Canadian policy and decision makers should take caution during budget cuts and implementing cost containment programs. The results suggest that reducing AMI budgets may have a negative effect on the quality of AMI care patients receive in Edmonton, Alberta. The linear relationship suggests that the return on the quality of AMI is consistent for each dollar invested with no economies of scale.