Vitamin D status and health correlates among apparently healthy participants in an urban, Sunny Region

Abstract

Aim: To assess vitamin D status and health correlates in a sample of apparently healthy Caucasian participants residing in an urban area, Athens, with latitude 370 58′ 0″ N and longitude 230 43′ 0″E, after taking into consideration a broad range of purported biological, behavioural and environmental factors. Method: Men and women 35+ years from a selected population (n=490) were studied. Participants completed a detailed questionnaire regarding socio-demographic, lifestyle, clinical and dietary characteristics. Biomarkers were measured after 12 h fasting. Linear and multinomial regression models were used to evaluate the association between 25(OH)D and determinants of vitamin D status. Results: Results revealed that one hour increase of sunlight exposure decreased the odds of having D deficiency (i.e., <20 ng/mL) by 70% (OR=0.30, 95% CI: 0.20-0.45), adjusted for age, sex, family status, physical activity, smoking habits, BMI, triglycerides, parathyroid hormone, uric acid, haptoglobin, folate acid and haemoglobin, as compared to sufficient levels (i.e., >30 ng/mL). Regarding biomarkers, parathyroid hormone and haptoglobin were found to be related with the odds of having vitamin D deficiency (OR=1.11, 95% CI: 1.05-1.16; OR=1.02, 95% CI: 1.00-1.03, respectively) as compared to the sufficient levels. Conclusions: Sufficient serum vitamin D levels were observed among participants with characteristics associated with reduced cardiovascular risk, such as normal BMI, increased physical activity, decreased parathyroid hormone and decreased inflammatory markers. Even a slight increase in sunlight exposure could have beneficial effects on serum vitamin D concentrations and eventually on haemoglobin and inflammatory markers levels, thus providing a simple and inexpensive lifestyle intervention that promotes public health.