Vitamin D insufficiency in southern Arizona

Area of Science:

• Endocrinology
• Nutritional Science
• Public Health

Background:

• Vitamin D deficiency is prevalent in northern US populations.
• Limited data exists on vitamin D status in high-sun exposure areas like Arizona.
• This study addresses the knowledge gap in southern Arizona's population.

Purpose of the Study:

• To determine serum 25-hydroxyvitamin D [25(OH)D] concentrations in southern Arizona residents.
• To identify predictors of vitamin D status in this population.
• To assess the prevalence of vitamin D deficiency in a sun-rich environment.

Main Methods:

• Cross-sectional analysis of serum samples from a colorectal adenoma prevention study.
• Categorization of participants based on serum 25(OH)D levels (<10, 10-19.9, 20-29.9, ≥30 ng/mL).
• Evaluation of demographic and lifestyle factors as predictors.

Main Results:

• Mean serum 25(OH)D was 26.1 ± 9.1 ng/mL.
• 25.4% of participants had vitamin D deficiency (<20 ng/mL), and 2.0% had severe deficiency (<10 ng/mL).
• Black and Hispanic individuals showed higher rates of deficiency compared to non-Hispanic whites. Sun exposure impacted vitamin D levels more in whites, while BMI was more significant in Black and Hispanic individuals.

Conclusions:

• Southern Arizona adults exhibit common vitamin D deficiency despite high sun exposure.
• Black and Hispanic populations are disproportionately affected by vitamin D deficiency.
• Understanding predictors like sun exposure and BMI is crucial for targeted interventions.