Vitamin A is a fat-soluble vitamin crucial for maintaining a wide range of physiological functions, with its most well-known role being in vision. It exists in two primary forms: preformed vitamin A (retinol and retinyl esters), found in animal-based foods like liver, eggs, and dairy, and provitamin A carotenoids (especially beta-carotene), found in colorful plant foods like carrots, sweet potatoes, and spinach.
One of vitamin A’s most vital roles is in eye health. It’s a key component of rhodopsin, a protein in the retina that allows us to see in low light. A deficiency can lead to night blindness, and in severe cases, xerophthalmia, a condition that can result in irreversible blindness. This is why vitamin A deficiency is a leading cause of preventable childhood blindness globally.
Beyond vision, vitamin A is a powerful modulator of the immune system. It supports the integrity of skin and mucous membranes—our body’s first line of defense against infections. It also enhances the function of white blood cells, helping the body fight off pathogens.
Vitamin A plays a significant role in cellular growth and differentiation, especially in the development of organs during pregnancy and early childhood. It’s essential for proper functioning of the heart, lungs, kidneys, and other organs.
Vitamin D: The Sunshine Vitamin for Bones, Immunity, and More
While deficiency can cause serious health issues, excessive intake (particularly through supplements, not food) can lead to toxicity, causing symptoms like liver damage, headaches, nausea, and even birth defects during pregnancy.
The recommended daily intake varies by age and sex, but for most adults, it’s around 700–900 micrograms (RAE) per day. A balanced diet rich in both plant and animal sources typically meets these needs, supporting lifelong health, strong immunity, and clear vision.
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