Low Intake of Zinc and Vitamin D Is Associated with High Blood Lead Level Proportion Amongst Male Workers with Lead Exposure.

Background/

Objectives

Nutritional intake plays an important role in modulating lead absorption and toxicity. In addition to micronutrient status, emerging evidence suggests that body fat distribution may influence heavy metal toxicokinetics, yet this aspect remains poorly explored in occupational settings. This study aimed to investigate the associations of dietary intake of zinc, calcium, vitamin D, and protein, as well as anthropometric indicators, with blood lead levels (BLLs) among lead-exposed male workers.

Methods

A cross-sectional study was conducted involving 144 male workers from five areas with varying degrees of environmental lead contamination in Java, Indonesia. Nutrient intake was assessed using a semi-quantitative food frequency questionnaire (SQ-FFQ). Anthropometric measurements included body mass index (BMI) and waist-to-height ratio (WHtR). BLLs were measured using inductively coupled plasma mass spectrometry (ICP-MS). Bivariate and multivariate analyses were performed to identify independent predictors of elevated BLLs.

Results

The median BLL was 6.8 µg/dL (Q1-Q3: 4.75-13.08), and 32% of participants had BLLs above 10 µg/dL. BLLs differed significantly across exposure areas (p < 0.001). In bivariate analysis, WHtR, protein intake, zinc intake, and vitamin D intake were significantly associated with BLLs. Workers with higher WHtR had a greater proportion of elevated BLLs (p = 0.023), whereas BMI was not associated. In multivariate analysis, low zinc intake (p = 0.031) and low vitamin D intake (p = 0.021) remained significant predictors of high blood lead levels.

Conclusions

Environmental exposure remains the main determinant of BLLs, while low intake of zinc and vitamin D increases the risk of high blood lead levels. Central adiposity, reflected by WHtR, may represent a potential anthropometric marker of lead burden, suggesting a potential role of body fat distribution in lead toxicokinetics that warrants further investigation.