Vitamin D

Vitamin D is a fat-soluble vitamin that is essential for the maintenance of overall health. It plays a crucial role in calcium absorption, bone health, and immune function.

Sources of Vitamin D

Vitamin D can be obtained through exposure to sunlight, as well as through dietary sources such as fatty fish (e.g., salmon, mackerel, tuna), egg yolks, and fortified foods (e.g., milk, orange juice, cereals).

Functions of Vitamin D

1. Calcium absorption: Vitamin D helps the body absorb calcium from the intestines, which is essential for maintaining strong bones and teeth.

2. Bone health: It helps in the regulation of calcium and phosphorus levels in the body, promoting bone mineralization and preventing conditions like osteoporosis.

3. Immune function: Vitamin D plays a role in supporting the immune system and may help reduce the risk of certain diseases.

Deficiency and Excess

A deficiency in vitamin D can lead to conditions such as rickets in children and osteomalacia in adults, characterized by weakened bones and skeletal deformities.

Excessive intake of vitamin D can lead to toxicity, causing symptoms such as nausea, vomiting, weakness, and kidney problems.

Recommended Intake

The recommended dietary allowance (RDA) for vitamin D varies by age and gender, but generally ranges from 400 to 800 international units (IU) per day.

Study Tips

• Understand the sources of vitamin D and the role of sunlight in its production in the skin.
• Memorize the functions of vitamin D in calcium absorption, bone health, and immune function.
• Be able to identify the symptoms and consequences of both vitamin D deficiency and excess.
• Review the recommended dietary intake of vitamin D for different age groups.