Conclusion Despite the limitations of the current evidence , the prevalence of vitamin D inadequacy in athletes is prominent .
The risk significantly increases in higher latitudes , in winter and early spring seasons , and for indoor sport activities .
The prevalence of injuries in athletes is notable but its association with  vitamin D status is unclear .
Background Vitamin D is essential for maintaining optimal bone health .
The prevalence of vitamin D inadequacy in athletes is currently unclear .
Objective The objective of this study is to determine the prevalence of vitamin D inadequacy in athletes .
Serum 25(OH)D is measured to clinical ly determine vitamin D status .
A global representation of vitamin D status in healthy populations
Purpose This paper visualizes the available data on vitamin D status on a global map , examines the existing heterogeneities in vitamin D status and identifies research gaps . Methods A graphical illustration of global vitamin D status was developed based on a systematic review of the worldwide literature published between 1990 and 2011 . Studies were eligible if they included sample s of r and omly selected males and females from the general population and assessed  circulating 25-hydroxyvitamin D [ 25(OH)D ] levels .  Two different age categories were selected : children and adolescents ( 1–18 years ) and adults ( > 18 years ) . Studies were chosen to represent a country based on a hierarchical set of criteria . Results In total , 200 studies from 46 countries met the inclusion criteria , most coming from Europe . Forty-two of these studies ( 21 % ) were classified as representative . In children , gaps in data were identified in large parts of Africa , Central and South America , Europe , and most of the Asia/Pacific region . In adults , there was lack of information in Central America , much of South America and Africa . Large regions were identified for which the mean 25(OH)D levels were below 50 nmol/L. Conclusions This study provides an overview of 25(OH)D levels around the globe . It reveals large gaps in information in children and adolescents and smaller but important gaps in adults . In view of the importance of vitamin D to musculoskeletal growth , development , and preservation , and of its potential importance in other tissues , we strongly encourage new research to clearly define 25(OH)D status around the world
Conclusion Despite the limitations of the current evidence , the prevalence of vitamin D inadequacy in athletes is prominent .
The risk significantly increases in higher latitudes , in winter and early spring seasons , and for indoor sport activities .
The prevalence of injuries in athletes is notable but its association with  vitamin D status is unclear .
Background Vitamin D is essential for maintaining optimal bone health .
The prevalence of vitamin D inadequacy in athletes is currently unclear .
Objective The objective of this study is to determine the prevalence of vitamin D inadequacy in athletes .
Serum 25(OH)D is measured to clinical ly determine vitamin D status .