Epidemiology of hypovitaminosis D among apparently healthy young adults in Algeria

Abstract

Background: Hypovitaminosis D is a global public health problem. In Algeria, little work is done on the epidemiology of vitamin D deficiency targeting all at-risk populations. Objectives: The main objective of this study is to estimate the prevalence of hypovitaminosis D in healthy young adults. The secondary objectives are to identify the determinants of vitamin D status and to analyze the correlations between plasma calcidiol levels and other parameters of phosphocalcic metabolism. Material and methods: Cross-sectional descriptive, prospective and multicentric epidemiological survey of 945 subjects belonging to the Region of Blida (Algeria), assessment of 25-hydroxy-vitamin D, calcium, phosphorus, parathormone, alkaline phosphatase and albumin for each subject. The study also included a questionnaire to identify the determinants of vitamin D status in this population. Results: There is a high prevalence of hypovitaminosis D (calcidiol < 30 ng/ml), with 92.6% of subjects affected, of whom 27.5% had an insufficiency (calcidiol 20 -29 ng/ ml), however 65.1% of subjects were deficient (calcidiol < 20 ng/ml). No significant correlation was detected between 25-hydroxy-vitamin D and plasma calcium (R=0.051; P=0.115), a significant positive correlation was found between 25-hydroxy-vitamin D and phosphorus (R=0.146; P< 0,05). A negative correlation was detected between calcidiol and parathormone (R= -0.886; P< 0,05) and between calcidiol and alkaline phosphatase (R= -0.828; P< 0,05). Based on multivariate analysis, the 3 top risk factors that were associated with hypovitaminosis D are sun exposure time <30 min (adjusted OR =202.11, [95% CI]: 48.91; 835.10; P< 0,05), lack of knowledge about vitamin D (adjusted OR =46.45; [95% CI]: 20.84 ;103.52; P< 0,05), and dark phototype (adjusted OR =39.67; [95% CI]: 14.31; 109.99; P< 0,05). Conclusions: Hypovitaminosis D can be considered a public health problem in Algeria affecting young healthy populations. It is necessary to develop multisectorial programs in order to better address risk factors, particularly modifiable ones, and develop a strategy for prevention and care.