How much vitamin D do you need?

Medically reviewed by Neka Miller, PhD on September 18, 2020. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

Known as the “sunshine vitamin” because the sun’s rays help your body make it, vitamin D plays a vital role in one’s health. For instance, it helps regulate calcium and phosphate, which are necessary nutrients that keep our bones, teeth, and muscles healthy. But, like many people, even if you know how important it is, you may wonder, “How much vitamin D do I need?”

Let’s take a closer look at recommendations for daily vitamin D intake—as well as a vitamin D test kit that may help you find out if you may have a deficiency.

Recommended amounts of vitamin D

The Health and Medicine Division of the National Academies of Sciences, Engineering, and Medicine recommends the following general intakes for vitamin D. (However, based on a number of factors, your healthcare provider may suggest doses that are higher or lower than what’s listed—so consider asking your provider for their recommendation.) The amount of vitamin D in foods and supplements is usually expressed in terms of International Units (IU), so “IU/day” refers to “International Units per day.”

Recommended dietary allowance (IU/day) for vitamin D followed by the upper intake level:

Infants 0-6 months

• 400 IU/day for adequate intake
• Upper intake level of 1,000 IU/day

Infants 6-12 months

• 400 IU/day for adequate intake
• Upper intake level of 1,500 IU/day

Children 1-3 years old

• Recommended dietary allowance of 600 IU/day
• Upper intake level of 2,500 IU/day

Children 4-8 years old

• Recommended dietary allowance of 600 IU/day
• Upper intake level of 3,000 IU/day

People 9-70 years old

• Recommended dietary allowance of 600 IU/day
• Upper intake level of 4,000 IU/day

People over 70 years old

• Recommended dietary allowance of 800 IU/day
• Upper intake level of 4,000 IU/day

The recommended intake of vitamin D during pregnancy and lactation is 600 IU per day for women ages 14-50, with an upper intake level of 4,000 IU/day.

How can you measure your vitamin D intake in International Units (IU)?

If you’re taking a vitamin D supplement, the amount of vitamin D will likely be listed on the supplement's nutritional label, either in International Units or micrograms (2.5 micrograms = 100 IU). Micrograms may be abbreviated as "mcg."

Vitamin D amounts aren’t always listed directly on the labels of food items. However, labels often do list the percent Daily Value (DV), which reflects the amount of vitamin D in a serving of that food as a percentage of 800 IU.

Finally, you can also get a sense of the vitamin D content of various kinds of food by visiting the National Institutes of Health's resource on vitamin D (see Table 3).

Effects of too much or too little vitamin D

Now that we’ve answered the question, “How much vitamin D do I need?” let’s cover what too much or too little vitamin D can do to your body’s health.

Too much vitamin D

Getting too much or an excessive amount of vitamin D can result in vitamin D toxicity. Think of this as the opposite of a vitamin D deficiency. Vitamin D toxicity may develop if you’re oversupplementing with vitamin D. You can’t get too much vitamin D through sunlight exposure because your skin has mechanisms in place to prevent this.

The main concern with vitamin D toxicity is that it can lead to an accumulation of calcium in your blood, which can result in nausea or vomiting, weakness, and frequent urination. It can also advance to bone pain, kidney issues, and calcium stones. There are several possible signs of too much vitamin D, such as the ones listed below.

Common symptoms of too much vitamin D include:

• Kidney stones
• Weight loss
• Diarrhea or constipation
• Nausea and/or vomiting
• Pain in your bones
• Frequent urination
• Fatigue or weariness
• Persistent headaches
• Irregular heartbeat

Inadequate vitamin D intake

When you aren’t getting enough vitamin D, vitamin D deficiency can develop—and a deficiency can lead to a number of different symptoms, including:

• Fatigue
• Joint pain
• Depression
• Muscle pain
• Weakness
• Thinning hair

Fortunately, vitamin D deficiency is often reversible with adequate supplementation (but be sure to consult with your healthcare provider if you do have a deficiency).

At-home test kits for vitamin D levels

A vitamin D testing kit is an easy way to check your levels and help you understand if you’re getting enough of the “sunshine vitamin” to support good health.

The Everlywell Vitamin D Test lets you check your levels right from home. The test uses a small sample of blood (collected via a simple finger prick) to help detect a vitamin D deficiency. This test can also tell you if your vitamin D levels are too high—a rare but possible occurrence known as vitamin D toxicity.

Taking this test is easy. After you order and receive the kit, you register it online using its unique code. Follow the simple instructions to collect your blood sample, then ship your sample to the lab for analysis (a prepaid shipping label is included with the kit). Results are viewable on our secure, online platform—and are easy to understand and easy to share with your healthcare provider so you can take action to support your health.

Related content

When should you take vitamin D?

References

1. Vitamin D. National Institutes of Health. URL. Accessed September 18, 2020.

2. Vitamin D Deficiency. Medline Plus. URL. Accessed September 18, 2020.

3. Vitamin D Deficiency. Cleveland Clinic. URL. Accessed September 18, 2020.