Chickens with vitamin A deficiency have an increased risk of getting sick. The two main mechanisms involved in the prevention of disease are the effect of vitamin A on the immune system and on epithelial integrity.

Vitamin A alleviates heat, cold and vaccination stress-related depression in poultry performance. From research it appears that dietary supplementation with 15,000 IU of vitamin A per kilogramme of feed improves performance and reduces oxidative stress markers in heat-stressed broilers.

Vitamin A plays a vital role in the health and well-being of chickens, contributing to various aspects of their growth, reproduction, and overall vitality. While chickens can naturally obtain some vitamin A through their diet, understanding its significance and ensuring proper supplementation is essential for poultry keepers.

Vitamin A deficient chicks are infected significantly with larger numbers and longer intestinal round worms compared with chicks receiving with an adequate vitamin A. The recovery of the affected chicks can be enhanced with increasing levels of vitamin A up to 10 times the minimal requirement under normal conditions.