Vitamin D Status and Routine Laboratory Data-Derived 25(OH)D Distributional Benchmarks in Adults from Şanlıurfa,...

Area of Science:

• Clinical Biochemistry
• Endocrinology
• Public Health

Background:

• Interpreting serum 25-hydroxyvitamin D [25(OH)D] requires distinguishing epidemiological thresholds from clinical decision limits.
• This study addresses the need for localized vitamin D status benchmarks using routine laboratory data.
• Understanding vitamin D levels is crucial for public health initiatives and clinical practice.

Purpose of the Study:

• To evaluate vitamin D status in adults from Şanlıurfa, Türkiye.
• To establish clinically pre-filtered, routine laboratory data-derived 25(OH)D distributional benchmarks.
• To analyze vitamin D status variations based on sex, age, and season.

Main Methods:

• Retrospective analysis of 48,826 adult records (aged 18-65) from a single-center routine laboratory database (2025).
• Serum 25(OH)D measured using Elecsys Vitamin D total III immunoassay.
• Data underwent eligibility, duplicate, analytical, and clinical pre-filtering; nonparametric 2.5th-97.5th percentile range calculated.

Main Results:

• A high prevalence of vitamin D deficiency (78.0%) and severe deficiency (35.2%) was observed.
• Median serum 25(OH)D was 12.74 ng/mL, with lower levels in females, younger adults, and during winter/spring.
• The clinically pre-filtered routine-data 2.5th-97.5th percentile range was determined to be 3.46-35.50 ng/mL.

Conclusions:

• Low serum 25(OH)D status is prevalent among routinely tested adults in Şanlıurfa.
• The derived range serves as a local distributional benchmark, not a clinical reference or decision limit.
• Findings emphasize the need for population-specific interpretation of vitamin D levels.