PE12.1-2 | Vitamin A — Summary & Reflection

KEY TAKEAWAYS

Vitamin A is a fat-soluble vitamin essential for rhodopsin synthesis (vision), epithelial differentiation, and immune function. The RDA for children 1–3 years is approximately 400 mcg RAE/day; preformed retinol is found in animal foods (liver, egg, dairy) and provitamin A carotenoids in dark-green leafy vegetables and orange-yellow fruits. The liver stores 6–12 months' reserve, released as retinol bound to RBP-transthyretin complex.

Deficiency produces the WHO xerophthalmia spectrum: XN (night blindness) → X1A (Bitot's spots) → X1B (corneal xerosis) → X2 (corneal ulceration) → X3A/X3B (keratomalacia = irreversible) → XF (fundal changes). Systemic features include phrynoderma, growth faltering, and immune suppression. Treatment is oral Vitamin A 200,000 IU on Day 1, Day 2, and Day 14 (halved for infants 6–12 months; quartered for <6 months). India's National Prophylaxis Programme delivers 1 lakh IU at 9 months and 2 lakh IU 6-monthly from 18 months to 5 years.

Toxicity (hypervitaminosis A) from excess intake: acute = bulging fontanelle, vomiting, skin peeling; chronic = bone pain, hepatotoxicity, alopecia, pseudotumour cerebri. Excess retinol in the first trimester is teratogenic; β-carotene does not cause toxicity.

REFLECT

Think about a health sub-centre or ASHA worker visit in a rural community. What barriers might prevent a child from receiving the 9-month Vitamin A dose alongside the MR vaccine? Consider caregiver awareness, stock availability, and health worker training. If you were designing a community intervention to improve Vitamin A prophylaxis coverage in a high-burden district, what single-point change would have the greatest impact — and how would you measure its success? Reflect on how the convergence of malnutrition, infections (particularly measles), and missed immunisation contacts creates a 'perfect storm' for xerophthalmia progression in vulnerable children.