PARADIGM SHIFTS IN VITAMIN D TESTING AND DIAGNOSIS: A DECADE-LONG OBSERVATIONAL STUDY

Abstract

Objective: Awareness about vitamin D deficiency has linearly increased over the years. Lack of clear guidelines regarding optimum dosage and inadvertent use of higher doses can lead to toxicity. This study was done to evaluate the changes in trends of vitamin D testing and status of serum levels of 25-hydroxy vitamin D (25-OHD) submitted for analysis to a large-volume reference laboratory.

Material and Methods: An observational study was conducted at the section of Chemical Pathology, Department of Pathology and Laboratory Medicine, Aga Khan University. Data analysis of serum 25-OHD tests from January 2010 to December 2019 was performed. The patients were categorized as deficient, insufficient, optimal, hypervitaminosis or toxic based on 25-OHD values. Data was analyzed using Microsoft Excel version 16.

Results: Total 903,282 tests were analyzed during the 10 years’ period Mean age (SD) was 40.7 (16.5) years, with 35.8% males. The 25-OHD testing since 2010 to 2019 increased by 62.3% in adults and 66.6% in children. The mean 25-OHD levels improved from 18.8 ng/ml in 2010 to 24.5 ng/ml in 2019 in adults, while no change in mean 25-OHD levels was noted in children.

Conclusion: Testing and status of vitamin D improved with increased mean vitamin D levels and a decline in deficiency over 10 years. Our study calls for developing local guidelines for vitamin D-deficiency management, and taking caution when prescribing supplements, as vitamin D intoxication is concurrently increasing in the population.

Key Words: 25OHD, Deficiency, Toxicity, Pakistan.