EPIDEMIC IN THE SHADOWS: VITAMIN D DEFICIENCY AMONG SOUTH ASIAN LABOR WORKERS

Abstract

Vitamin D deficiency is worryingly prevalent among labor workers in South Asia—despite the region’s abundant sunlight—posing serious public health and economic challenges. A recent meta‑analysis covering 44,717 adults across five South Asian countries reported a pooled deficiency prevalence of 68% (95% CI: 64–72%), with the highest rates in Pakistan (73%), Bangladesh (67%), India (67%), Nepal (57%), and Sri Lanka (48%). This paradox stems from multiple intertwined factors: prolonged indoor work in factories and shaded construction sites, clothing norms limiting skin exposure, sun-avoidant behaviours, heavy melanin pigmentation that reduces UVB-driven synthesis, air pollution, and low dietary intake of vitamin D–rich or fortified foods. In Southeast Asia, indoor and night-shift workers are particularly at risk—a Singapore study found 32.9% had serum 25(OH)D levels below 50 nmol/L, with office, workshop, and night-shift workers exhibiting significantly higher deficiency prevalence than outdoor control room staff. Health implications are profound: beyond skeletal issues like osteomalacia, deficiency contributes to muscle weakness, fatigue, higher fracture risk, and susceptibility to chronic and infectious diseases—including respiratory and cardiovascular conditions. For laborers, these translate into increased absence from work’, reduced productivity, and diminished economic output. Addressing this multifaceted problem demands integrated strategies: culturally tailored education, promotion of safe sun exposure during optimal UVB hours, workplace policies enabling outdoor breaks, targeted supplementation, and food fortification. Such interventions offer the promise of improved worker health, enhanced productivity, and stronger socio-economic outcomes across South Asia.