The Double-Edged Sword of Vitamin A: Function and Toxicity

Vitamin A is crucial for vision, immune function, growth, reproduction, and skin health, existing as preformed vitamin A and provitamin A carotenoids. Deficiency can cause night blindness, infections, and skin issues, while excess intake, especially from supplements, can lead to toxicity affecting the liver, bones, and nervous system, and pose risks during pregnancy. Deficiency is a concern in low-income countries, whereas preventing toxicity is vital in high-income areas due to supplement use. Strategies like education, nutritional screening, and food fortification are essential, with further research needed on safe dosages and therapeutic applications for vulnerable groups.