Lamiaa Elsayyad, Alaa Shafie, Mazen almehmadi, Khadiga Ahmed Ismail, Yaser O. Abu Asi, Hatem H. Allam

Abstract

Background: Vitamin D has a dramatic effect on health and a significant role in disease prevention. Inadequate dietary system and decreased sun exposure are the most important causes of vitamin D deficiency. The traditional intervention for vitamin D deficiency is supplements. Aim: The aim of our study was to evaluate the vitamin D status in teenagers and investigate the influence of activity level on vitamin D in this age group. Materials and methods: 204 male teenagers were recruited from Taif secondary schools. Their age ranged from 14 to 16 years, they had the same pubertal stage. They had not used vitamin D or calcium supplements for four months. Physical activities were measured using the piezoelectric pedometer. Dietary intake was calculated using the food frequency questionnaire. Also, sun exposure was calculated by the number of day hours spent outdoor. Results: There were no significant differences among the groups regarding sun exposure and dietary intake (P<0.05). Regarding vitamin D level, there was a significant increase in the more active groups, (active and highly active groups) (P>0.05), when compared with the less active groups. Also, the Pearson correlation showed highly significant correlation between the activity level and vitamin D level (r=0.418) and significance value of. 0.000. Conclusion: Physical activity level can affect vitamin D serum levels when the effect of sun exposure and dietary intake is controlled. There is a highly significant correlation between physical activity level and serum vitamin D level‎.