Vitamin D is essential for bone calcification while low levels of the vitamin are associated with the production of parathyroid hormone that resorbs bone tissue. Few researches have studied the determinants of vitamin D status in young people through variables which entail lifestyle, sociodemographic, and anthropometric records. 25-hydroxyvitamin D is the hydroxylated form and a good indicator of vitamin D. The purpose of this study was to investigate the relationship between the variables and circulating 25-hydroxyvitamin D in a group of untreated young people. 738 persons aged between 18 and 25 were selected from learning centers and enrolled in a cross-sectional study. For multivariate logistic regression, participants were classified according to their serum 25-hydroxyvitamin D concentration into three categories, which included vitamin D sufficiency, vitamin D insufficiency, and vitamin D deficiency. Data on lifestyle factors and education was gathered through self-reported questionnaires. 700 subjects that had a valid measurement of serum 25-hydroxyvitamin D concentration and a fully filled questionnaire were analyzed. The study revealed that vitamin D deficiency was predominant in young adults. Indeed, 34% and 19% of the subjects had vitamin D insufficiency and vitamin D deficiency, respectively. Few individuals with acute vitamin D deficiency required special attention. Moreover, vitamin D deficiency was more prevalent among men, obese persons, smokers, participants who exercised only half an hour per week, and participants who ate fast food regularly. Finally, variable factors like smoking, maintaining a healthy BMI, and exercising constitute probable targets for interventional studies in determining the causal order.
UVB is necessary for the synthesis of vitamin D3, which needs to be taken in account when analyzing the present results. Indeed, the study was carried out in Copenhagen and the young adults’ vitamin D status in this area showed great disparities between seasons. Furthermore, the cross-sectional study design applied does not permit for a temporal ordering of the relationships between the serum vitamin D status and several other factors such as fish consumption to be ascertained. Additionally, only participants from learning centers were included in the study, thus, leading to selection bias. Nonetheless, the results obtained from this study can be applied for improving the vitamin D status of young people at high risk of severe deficiency by educating them about the significance of consuming vitamin D.
Tønnesen, R., Hovind, P. H., Jensen, L. T., & Schwarz, P. (2016). Determinants of vitamin D status in young adults: Influence of lifestyle, sociodemographic and anthropometric factors. BMC Public Health, 16(1), 385.