Vitamin D facts for kids

Vitamin D is a special substance that acts like a hormone in your body. Your body can make it when you get enough sunlight. If you don't make enough, you can also get it from certain foods or supplements. Even though it's called a 'vitamin,' it's actually more like a hormone because your body can produce it on its own.

What Vitamin D Does

Vitamin D helps your body in many important ways. It was first found because it could stop and fix a bone disease called rickets.

It helps control the amount of calcium and phosphates in your blood. These are important minerals. Vitamin D also helps your body take in calcium and magnesium from the food you eat. This happens in your intestines.

Most importantly, Vitamin D helps your bones grow strong and healthy. It's also really good for your immune system, which helps fight off sickness.

Different Kinds of Vitamin D

There are five different types of Vitamin D, from D₁ to D₅. The two most common types are D₂ and D₃.

Vitamin D₃ (Cholecalciferol)

Your body makes D₃ when your skin is exposed to sunlight. You can also find D₃ naturally in oils from sea animals and in lanolin. Lanolin is an oil that comes from sheep's wool. This is often used to make Vitamin D supplements.

Vitamin D₂ (Ergocalciferol)

D₂ is made by fungi, like mushrooms. It's similar to D₃ but not exactly the same.

Getting Enough Vitamin D

Your skin makes D₃ from cholesterol when it gets enough ultraviolet light. Sunlight has ultraviolet light, so spending time in the sun is one way to get D₃.

Why Some People Don't Get Enough

Many things can stop your skin from making enough D₃:

• In winter, sunlight might not be strong enough.
• Melanin is what gives skin its color and protects it from sun damage. People with darker skin have more melanin, which can make it harder for their skin to produce D₃.
• Older people's skin makes less D₃, even with enough sunlight.
• Clothing, glass, and sunscreens can block the ultraviolet light.

How Much Vitamin D Do You Need?

It can be tricky to know exactly how much extra Vitamin D you might need. Health groups often suggest different amounts. Most recommendations are less than 25 micrograms (which is 1000 IU) per day. However, up to 100 mcg (4000 IU) per day is usually considered safe. Some experts suggest that most adults could benefit from at least 20-25 mcg (800-1000 IU) per day.

If you are pregnant, breastfeeding, or older, it's often safest to take at least 15-20 micrograms (600-800 IU) of Vitamin D every day.

Foods with Vitamin D

Very few foods naturally have a lot of D₃. Oily fish like salmon, sardines, and mackerel are good sources. Some edible mushrooms, like shiitake, contain D₂. Mushrooms grown in full sunlight tend to have more.

You can easily find D₃ supplements for sale in most developed countries.

Vitamin D is a fat-soluble nutrient. This means your body can store any extra Vitamin D in fat tissue for later use.

Treating Vitamin D Deficiency

If someone doesn't have enough Vitamin D, they can take Vitamin D supplements. Spending a safe amount of time in the sun, without getting sunburnt, can also help.

Images for kids

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  cholecalciferol (D₃)

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  ergocalciferol (D₂)

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  Calcium regulation in the human body. The role of active vitamin D (1,25-dihydroxyvitamin D, calcitriol) is shown in orange.

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  In the epidermal strata of the skin, vitamin D production is greatest in the stratum basale (colored red in the illustration) and stratum spinosum (colored light brown).

See also

In Spanish: Vitamina D para niños