Are lifestyle factors good predictors of retinol and vitamin C deficiency in apparently healthy adults?

Objective: To examine interrelationships between (1) dietary habits, (2) socioeconomic and (3) environmental factors, and their impact on plasma retinol and plasma ascorbic acid. Design: Cross-sectional study on adults from Western India. Setting: Rural, semi urban, urban higher/middle/lower socioeconomic regions (HSE/MSE/LSE) having diverse dietary habits and environmental conditions. Subjects: A total of 214 men and 108 women (20-50 y), apparently healthy and non-anemic. Main outcome measures: Food intake by food frequency questionnaire, weight, height, age, smoking, environmental score, education, income, plasma retinol and plasma ascorbic acid. Results: Mean plasma retinol in women (24.84+/-5.1 mug/dl) and men (24.75+/-4.53 mug/dl) were not significantly different and 21% had plasma retinol below 20 mug/dl. Mean plasma ascorbic acid in women (0.35+/-0.12 mg/dl) and men (0.30 +/- 0.12 mg/dl) was similar with 75% having plasma ascorbic acid below 0.4 mg/dl. Vitamin A intake (as retinol equivalent) and plasma retinol showed a significant dose response (P < 0.05) but not vitamin C intake and plasma ascorbic acid. Plasma retinol showed significant correlation with income (ρ = 0.24), education (ρ = 0.27), and environment (ρ = 0.21; ρ = 0.0001). Similar correlations with plasma ascorbic acid were 0.29, 031, -0.23 respectively (P = 0.0001). Logistic regression showed education, environment, green leafy vegetables (GLV) and milk intake as predictors of plasma retinol deficiency, while non-sweet fruit intake, education and passive smoking for plasma ascorbic acid deficiency (P < 0.05). Conclusions: Subnormal status of retinol and vitamin C emphasizes the need to increase consumption of fruit, GLV and milk products, and also better education and environment. Avoiding passive smoking demands attention in order to improve levels of these vitamins.