What Is Vitamin D In International Units & What Foods Can I Find It In?

Here you can read about what vitamin D is, both D2 and D3, measured in International Units (IU).

Vitamin D exists in two forms, Vitamin D2 and Vitamin D3. Despite its name, vitamin D is not a vitamin. It is a hormone that can be synthesized by sunlight.

It is fat-soluble vitamin, which means that the body does not need these every day. We have the potential to store it in our bodies.

Table of Contents

Vitamin D2 And Vitamin D3

Vitamin D exists in two forms. Vitamin D2 and Vitamin D3. (src )

There are a few differences between the two D vitamins. You can read more on Vitamin D, D2 and D3.

It's difficult for people to get enough vitamin D from food alone.

Supplements are an alternative, but taking too much vitamin D supplements over a long period can cause too much calcium to build up in the body.

So be careful and take the right amount.

International Units

IU stands for International Units. It is a unit of measurement for vitamins and other specific substances.

It is commonly used to measure fat-soluble vitamins, like Vitamin A, D, and E.

Vitamins are measured in milligrams, micrograms, or international units.

Milligrams and micrograms show the amount of mass in a sample.

But international units show the level of biological activity of the substance. (src )

Vitamin D Unit Conversion

Vitamin D in International Units is calculated by multiplying the serum 25-hydroxyvitamin D level by 2.5.

25-hydroxyvitamin D is the most abundant form in human serum and is considered to be the bioactive form of vitamin D.

Conversion between international units and micrograms is easy with or without a calculator. (src )

How to convert Vitamin D International Units to micrograms

To convert Vitamin D from International Units to micrograms all you have to do is multiply IU with 0.025 or if you don't have a calculator, divide the IU with 100 and then multiply it with 2.5.

Examples international units to micrograms

International units: 400 IU

International units: 1000 IU

How to convert Vitamin D micrograms to International Units

To convert Vitamin D from micrograms to International Units all you have to do is multiply the mcg with 40.

Examples micrograms to international units

Micrograms: 10 mcg

Micrograms: 25 mcg

Foods You Can Find Vitamin D (D2 + D3), International Units In

You find Vitamin D (D2 + D3), International Units mostly in fats and oil, vegetable, seafood, and american indian and alaska native food products.

Examples of food sources include

Foods in our nutrition tool

You can find regularly updated top-ranked lists of foods for over 200+ nutrients in our nutrition tool.

If you are interested in what foods contain the most Vitamin D (D2 + D3), International Units, we recommend you visit our tool.

Here's our top-ranked list of foods that contain Vitamin D (D2 + D3), International Units.

Sara Niemelä

co-founder Care Omnia, Head Content Creator

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Nutrition is my passion. I've spent thousands upon thousands of hours reading, analyzing, categorizing and comparing research studies.

I’m a wife and a mother of three. I enjoy the outdoors, cooking, and spending time with my family.