Date of Award

2026-08-01

Degree Name

Master of Public Health

Department

Public Health

Advisor(s)

Gabriel Ibarra-Mejia

Abstract

Background: Vitamin D deficiency is a persistent public health concern, even among outdoor workers who receive substantial sunlight exposure. Landscaping workers may still be at risk because sun-protective clothing, early work hours, behavioral practices, and low dietary intake can reduce effective vitamin D synthesis. Purpose: This pilot study examined dietary vitamin D intake, sun exposure behaviors, and serum 25-hydroxyvitamin D status among male landscaping workers in El Paso, Texas, to identify behavioral and nutritional factors associated with deficiency. Methods: Twenty participants completed a culturally adapted food frequency questionnaire and behavioral assessment and underwent capillary point-of-care testing for serum 25(OH)D. Descriptive statistics, non-parametric tests, and correlation analyses were used because of the small sample size. Results: Dietary vitamin D intake was low, with a mean intake of 169 IU/day, below the recommended intake of 600 IU/day. Despite mean occupational sun exposure of 45.35 hours/week, 85% of participants had suboptimal serum 25(OH)D levels, including 30% classified as deficient and 55% as insufficient. Dietary vitamin D intake was positively correlated with serum 25(OH)D concentration, whereas weekly sun exposure was inversely correlated with serum 25(OH)D concentration. Readiness to adopt sun-protective behaviors was also associated with serum 25(OH)D status. Conclusions: Vitamin D deficiency was common among landscaping workers in El Paso, Texas, despite substantial occupational sun exposure. The findings suggest that high sunlight exposure alone is not sufficient to maintain adequate vitamin D status in this population. Low dietary vitamin D intake appears to be a key contributor to suboptimal serum 25(OH)D levels, highlighting the importance of considering both behavioral and nutritional factors in occupational health research. Recommendations: Workplace and public health interventions should include culturally appropriate nutrition education, promotion of vitamin D-rich foods, and consideration of supplementation or food fortification strategies for high-risk outdoor workers. Occupational health programs may also benefit from incorporating vitamin D screening into preventive health efforts, especially for workers with limited dietary intake or high sun-protective practices. Future studies should use larger samples to confirm these findings and further examine the relationship between sun exposure behaviors, dietary intake, and vitamin D status.

Language

en

Provenance

Received from ProQuest

File Size

89 p.

File Format

application/pdf

Rights Holder

Cristela Anahi Avila

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