Vitamin A

Vitamin A is a fat-soluble vitamin that is essential for maintaining good vision, a healthy immune system, and cell growth. It is found in two forms: preformed vitamin A (retinol and retinyl esters) and provitamin A carotenoids (such as beta-carotene).

Sources of Vitamin A

• Animal sources: liver, fish liver oils, dairy products, and egg yolks
• Plant sources: colorful fruits and vegetables such as carrots, spinach, sweet potatoes, and red bell peppers

Functions of Vitamin A

• Supports vision: Vitamin A is essential for the proper functioning of the retina and is important for low-light and color vision.
• Immune function: It plays a crucial role in maintaining the health of the immune system, helping the body fight off infections and illnesses.
• Cell growth and development: Vitamin A is necessary for the growth and development of cells, including those of the skin and mucous membranes.

Deficiency and Toxicity

Vitamin A deficiency can lead to night blindness, increased susceptibility to infections, and in severe cases, can cause xerophthalmia (dryness of the eye surface). On the other hand, excessive intake of vitamin A can lead to toxicity, which may cause symptoms such as nausea, dizziness, and in severe cases, liver damage.

Study Guide

Here are some key points to remember about Vitamin A:

1. Vitamin A is essential for vision, immune function, and cell growth.
2. It is found in animal sources like liver and dairy products, as well as in colorful fruits and vegetables.
3. Deficiency can lead to night blindness and increased susceptibility to infections.
4. Excessive intake can lead to toxicity and liver damage.

Remember to include a variety of sources of vitamin A in your diet to maintain good health!