Vitamin D

Overview

Vitamin D is a fat-soluble vitamin that is essential for maintaining the health of bones and teeth. It also plays a key role in supporting the immune system, brain, and nervous system. There are several forms of vitamin D, but the two most important ones are vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol).

Sources of Vitamin D

The primary source of vitamin D is sunlight. When the skin is exposed to sunlight, it produces vitamin D. Additionally, vitamin D can be obtained from certain foods such as fatty fish (salmon, mackerel, tuna), egg yolk, cheese, and fortified dairy products.

Functions of Vitamin D

• Promotes the absorption of calcium and phosphorus in the body
• Supports bone health and development
• Regulates immune function
• Helps in the maintenance of a healthy nervous system
• Supports muscle function

Deficiency and Excess

A deficiency in vitamin D can lead to rickets in children and osteomalacia in adults, both of which are conditions characterized by weakened and soft bones. On the other hand, excess vitamin D can lead to toxicity, causing symptoms such as nausea, vomiting, weakness, and kidney problems.

Study Guide

When studying vitamin D, it's important to focus on its sources, functions, and the effects of deficiency and excess. Make sure to understand the role of vitamin D in bone health and how it interacts with calcium and phosphorus. Practice identifying foods and activities that can help maintain adequate levels of vitamin D in the body.

Additionally, familiarize yourself with the conditions associated with vitamin D deficiency and toxicity, and the recommended dietary allowances for different age groups. Understanding the different forms of vitamin D and their absorption in the body is also crucial for a comprehensive grasp of the topic.