Relationship of total 25-OH vitamin D concentrations to Indices of Multiple Deprivation: geoanalysis of laboratory results

Abstract

Background: Vitamin D deficiency appears to be widespread and associated with ethnicity and economic status. Geography is the key to virtually all national statistics. It provides a structure for collecting, processing, storing and aggregating data. Linking geographic data to laboratory data allows analysis of the association of laboratory data with economic indicators.

Methods: The laboratory information system was searched to create a data-set of total 25-OH vitamin D concentrations, which was then linked to economic (Indices of Multiple Deprivation [IMD]) and ethnicity data using postcodes geocoded to Lower Super Output Areas (LSOAs).

Results: A total of 12422 25-OH vitamin D requests were received during the time period searched. A total of 12167 of these had associated postcodes that would allow georeferencing to LSOAs. The median total 25-OH vitamin D was 24.5 nmol/L (5.3-99.0; 2.5-97.5th percentile). Statistically significant (Spearman rank) correlations were found between median 25-OH vitamin D (nmol/L) and percentage of non-White population and percentage of non-White population and IMD. No statistically significant correlation between median 25-OH vitamin D concentration and IMD was found; however, a statistically significant correlation between percentage of population classified as severely deficient and IMD was found.

Conclusions: In summary, vitamin D deficiency is widespread and is related to ethnicity; it does not appear to be related to economic status except in cases of severe vitamin D deficiency.