Vitamin Deficiency in Golestan Province, Northern Iran: A High-risk Area for Esophageal Cancer
Objectives: Dietary factors seem to play a major role in esophageal carcinogenesis in Golestan Province, a high-incidence area for esophageal cancer in northern Iran. The current study was conducted to evaluate previous reports on severe deficiency of vitamin intake in Golestan. Methods: Using a food frequency questionnaire, food intake data were collected from 30,463 healthy participants in the Golestan Cohort Study. Intake of selected nutrients was compared with recommended daily allowance and lowest threshold intake values. Results: Vitamin A intake in the majority of participants was lower than recommended values. The proportion of participants with intakes lower than lowest threshold intake was as follows: urban men, 20%; urban women, 31%; rural men, 48%; and rural women, 64%. The pattern of vitamin C deficiency was similar to that of vitamin A, however, vitamin C deficiency was less common. Daily intake of vitamin C lower than the LTI was as follows: urban men, 6%; urban women, 9%; rural men, 13%; and rural women, 19%. On the other hand, protein intake in the majority of the general population in Golestan was higher than recommended values. Conclusion: Severe deficiency in vitamin intake among women and rural dwellers may partly explain the high incidence of EC among inhabitants in rural areas and the male:female ratio that is approximately 1 in Golestan; while EC is much more common in men in many low-incidence areas.