Vitamin D deficiency has been associated with an increased risk of hypothyroidism and autoimmune thyroid disease. Our aim was to investigate the influence of vitamin D supplementation on thyroid function and anti-thyroid antibody levels.

While Canada has socialized most of the costs of treating illness, Canada has maintained a reliance on individuals interacting through private markets to invest in upstream health promotion and disease prevention. The failure of the market to provide the efficient level of upstream investment in health is leading to large and avoidable increases in the need for downstream medical treatment. The way to reduce the future deadweight loss of illness and disease is for provincial governments to address the upstream market failures through an expansion of the scope of public payment for health care to include upstream services for health promotion and disease prevention. Perhaps somewhat counterintuitively, spending public health-care dollars across a broader range of health and wellness services can result in spending less in total, because of the efficiency gains that will come from better health in the population. That is certainly what the evidence from a unique Albertan pilot project leads us to conclude. The Pure North S’Energy Foundation is a philanthropic initiative that pays for and provides preventative health-care services for Albertans drawn from groups that are vulnerable to poor health. This includes homeless people, people suffering from addiction, people with low incomes, people in isolated areas and susceptible seniors. The health improvements observed in those participating in the Pure North program have been significant. Effective health-promotion and disease-prevention services obviously benefit patients. But there are also substantial benefits to society as well. The annual health-care bill for a Canadian in poor health is estimated to be more than $10,000 higher than for someone in good health, meaning that keeping people in good health can be an important means for controlling public health-care budgets, and can free up scarce acutecare hospital resources. If the Pure North program were scaled-up province-wide to cover the nearly quartermillion Albertans in poor health, the resulting health improvement seen in Pure North participants could translate into a nearly 25-per-cent reduction in hospital days used by Alberta patients every year and a net savings of $500 million on hospital and physician costs. That does not even include the economic benefits of keeping workers in better health and productive, while spending fewer days ill or hospitalized. To date, Canada’s approach to health care has largely left it to patients to choose whether to seek healthpromotion and disease-prevention services on their own, suggesting an implicit deference to an individual’s rights and responsibilities. But for many low-income, isolated, addicted or aboriginal Canadians, there often is no choice: These services, when delivered privately, are often too expensive or may be otherwise inaccessible. The initial spirit behind Canadian medicare was to correct a health-market failure, so that no patient would face barriers to accessing necessary treatments. That same philosophy also recommends extending universal coverage for health-promotion and disease-prevention to vulnerable Canadians who today face similar barriers to access. If the Alberta government wants to show both foresight and fairness, the benefits from this kind of program, economically and societally, are simply too attractive to disregard.

The importance of dose, frequency and duration of vitamin D supplementation for plasma 25(OH)D levels is not well described and rarely reported for supplementation that exceeds 2000 IU per day. The objective is to examine dose, frequency and duration of supplementation in relation to plasma 25(OH)D in a large population-based sample. We accessed data on 2714 volunteers that contributed to 4224 visits and applied multilevel regression. Compared to not using supplements, a minimum regimen of 1000-2000 IU once or twice per week for one month was not effective in raising 25(OH)D. Compared to this minimum regimen, higher doses of 2000-3000, 3000-4000, and 5000 IU or more were associated with a 7.49, 13.19 and 30.22 nmol/L 25(OH)D increase, respectively; frequencies of three to four, five to six and seven times/week were associated with a 5.44, 16.52 and 30.69 nmol/L increase, respectively; and supplementation of five months or longer was associated with an increase of 6.68 nmol/L (p < 0.01 for all). Age, body weight, physical activity, smoking, and self-rated health were significantly associated with 25(OH)D. Whereas dose, frequency and duration of supplementation are important to healthy subjects committed to optimizing their nutritional status, to the design of clinical trials, individual characteristics and lifestyle contribute substantially to 25(OH)D.

Vitamin D status has been implicated in insulin resistance, type 2 diabetes mellitus, and hypertension, but the range of vitamin D status values over which the association can be found is unknown. Our objective was to define this range in a cohort of nondiabetic adult Canadians. We used a regression modeling strategy, first adjusting insulin-response variables and systolic and diastolic blood pressure for BMI, waist circumference, weight, age, and sex. The resulting residuals were regressed against serum 25-hydroxyvitamin D [25(OH)D] concentration using successive 40% data blocks ranging from the 0th to the 60th percentile of 25(OH)D values. All of the predictor variables were significantly associated with each of the dependent variables, with BMI and waist circumference accounting for >98% of the explained variance. The vitamin D association was localized to the serum 25(OH)D range extending from ∼40 to ∼90 nmol/L (16–36 μg/L). We conclude that vitamin D status is inversely associated with insulin responsiveness and blood pressure. Consistent with the threshold response characteristic typical of nutrients, the association was strongest in a circumscribed region of the range of 25(OH)D values. There was no association at 25(OH)D values >80–90 nmol/L (32–36 μg/L), indicating that the vitamin D association applied principally to values below that level. The differences observed, if they can be further confirmed in prospective studies, are of a magnitude that would be clinically important.

Objective The objective of this study was to quantify the relationship between number of dental amalgam surfaces and urinary mercury levels. Methods This study uses participant data from a large philanthropic chronic disease prevention program in Calgary, Alberta, Canada. Urine samples were analysed for mercury levels (measured in μg/g-creatinine). T-tests were used to determine if differences in urine mercury were statistically significant between persons with no dental amalgam surfaces and one or more dental amalgam surfaces. Linear regression was used to estimate the change in urinary mercury per amalgam surface. Results Urinary mercury levels were statistically significantly higher in participants with amalgam surfaces, with an average difference of 0.55 μg/g-creatinine. Per amalgam surface, we estimated an expected increase of 0.04 μg/g-creatinine. Measured urinary mercury levels were also statistically significantly higher in participants with dental amalgam surfaces following the oral administration of 2,3-dimercaptopropane-l-sulfonate (DMPS) and meso-2,3-dimercaptosuccinic acid (DMSA) which are used to mobilize mercury from the blood and tissues. Discussion Our estimates indicate that an individual with seven or more dental amalgam surfaces has 30% to 50% higher urinary mercury levels than an individual without amalgams. This is consistent with past literature that has identified seven amalgam surfaces as an unsafe level of exposure to mercury vapor. Our analysis suggests that continued use of silver amalgam dental fillings for restorative dentistry is a non-negligible, unnecessary source of mercury exposure considering the availability of composite resin alternatives.