Vitamin D – dietary intake, supplementation and metabolic status of Polish adults

ObjectivesContrary to popular opinion on the preventive properties of vitamin D, results of previous studies have been inconclusive. The aim of this research was to evaluate the associations between the intake of vitamin D and metabolic abnormalities in a representative sample of Polish adults.Material and MethodsWithin the framework of the Multi-Center National Population Health Examination Survey (referred to as WOBASZ), a random sample of 2381 adult residents of Poland (53.8% of whom were women) was examined. All the study subjects were extensively reviewed, including 24-h dietary recall. The intake of vitamin D was assessed on the basis of dietary and supplements reviews. Metabolic abnormalities were evaluated using measurements of waist circumference (WC), blood pressure (BP), serum triglycerides (TG), high-density lipoprotein cholesterol (HDL-C) and fasting glycemia. Metabolic syndrome was defined according to the International Diabetes Federation.ResultsOf all the study participants, about 4.4 % of women and 2.6% of men declared a regular supplementation of vitamin D. Among women, a significant inverse correlation between vitamin D supplementation and the mean systolic BP was found (p < 0.01). A more substantial relationship was noted after dividing the study subjects according to their body mass. Among obese men, there was a significant inverse relationship between vitamin D intake and the mean systolic BP (p < 0.01) and diastolic BP (p < 0.05), as well as a positive correlation with HDL-C (p < 0.05). Among obese women, a negative correlation was found between vitamin D supplementation and the mean systolic BP (p < 0.01) and diastolic BP (p < 0.05), and a positive correlation with TG (p < 0.05). Among non-obese male subjects, a negative correlation between vitamin D intake and WC was observed.ConclusionsThe obtained findings suggest that the correlation between vitamin D intake and metabolic abnormalities may depend on the obesity status. A higher vitamin D intake may reduce BP and increase HDL-C in obese subjects. The positive relationship between vitamin D intake and TG concentration in women needs further investigation.