Lesson 18 – Sunlight and Vitamin D

Share to Brightspace Continue with Brightspace

Read About Sunlight and Vitamin D


Read the vocabulary terms to understand the reading better.

Calcium is a mineral found mainly in the hard part of bones.

The equator is an imaginary horizontal line around the middle of Earth, dividing it into halves called the Northern Hemisphere and the Southern Hemisphere.

Minerals are natural elements, or substances, from the ground that are present in food and are needed by our bodies to grow and function properly.

SPF stands for sun protection factor and is a measure of how much solar energy, or UV radiation, is needed to produce sunburn on protected skin as compared to unprotected skin.

Vitamin D is a vitamin that is very important for the healthy growth of bones and teeth; vitamin D is found in fish-liver oils, egg yolks, milk, and sunshine.

Sunlight and Vitamin D

You have to make decisions about how to keep your body fit. You decide what to eat and how to get enough exercise. You may also decide to stay out of the sunlight and not allow your skin to burn.

Skin cancer caused by being out in the sunlight too much is a health concern. But people need sunlight to make vitamin D. How can you get enough of this nutrient without damaging your skin?

Why You Need Vitamin D

Vitamin D helps bones grow and stay strong. Calcium and other minerals are stored in bones. Your bones need vitamin D to absorb these minerals properly.

Why Do People Not Get Enough Vitamin D?

Your body makes a lot of vitamin D when it gets sunlight. People may avoid sunlight to protect their skin. Where you live can also make it difficult to get vitamin D from sunlight. Why? You may have to cover up to be warm or to cool off. Also, sunlight gets weaker as you move away from the equator. So people who live far from the equator do not get enough vitamin D.

Sunscreen also reduces the amount of sunlight your skin receives. Sunscreen with an SPF of 15 can block 99 percent of your body’s vitamin D production.

To learn more about Vitamin D, watch the video by Sunlight Institute on Youtube.

Now Show What You Know!

Complete some questions about the reading selection by clicking “Begin Questions” below.