Vitamin A

Excerpt

Vitamin A is a crucial component of various fat-soluble compounds, including retinol, retinyl palmitate, and β-carotene. These compounds are essential for vision, cellular differentiation, epithelial integrity, immune function, and gene regulation. Vitamin A is obtained from dietary sources as preformed vitamin A found in animal products and provitamin A carotenoids in plant-based foods. Both of these forms must be converted into retinal and retinoic acid for biological activity. Vitamin A deficiency is a global public health concern that can lead to issues such as xerophthalmia and increased childhood morbidity. Conversely, excessive intake causes hypervitaminosis A, which can lead to acute and chronic health effects. Contraindications include pregnancy, breastfeeding, and hepatic or renal disease.