Vitamin D is best known for supporting bone health, but research shows it also plays an important role in maintaining healthy skin. If you’re living with eczema and have a vitamin D deficiency, your healthcare provider may recommend a vitamin D supplement.

Eczema is a chronic inflammatory skin condition that occurs when the immune system overreacts, leading to skin barrier disruptions. The most common type is atopic dermatitis. Understanding how vitamin D contributes to skin health may help you better manage eczema symptoms.

Before adding any new supplements to your routine, talk with your doctor or dermatologist to find the dose that’s right for you.

What Is Vitamin D’s Role in the Body?

Also known as calciferol, vitamin D is a fat-soluble vitamin that’s important for both skin and bone health. It helps the body absorb calcium in the stomach, promoting strong, healthy bones. Vitamin D also helps calm inflammation and supports the skin’s barrier, two key factors in managing eczema.

Vitamin D comes from multiple sources: Your body can make it when ultraviolet (UV) rays from sunlight hit the skin, or you can get it from certain foods and supplements.

In the U.S., around 35 percent of adults have a vitamin D deficiency.

There are two main types of vitamin D, D2 (ergocalciferol) and D3 (cholecalciferol). Vitamin D2 mostly comes from plant sources and fortified foods. Vitamin D3 is produced in the skin from sunlight and can also be found in animal-derived foods like fatty fish, liver, and egg yolks. It’s also available in supplements, including some plant-based versions made from lichen.

Vitamin D Deficiency

In the United States, an estimated 50 percent of children ages 1 to 5 and 70 percent ages 6 to 11 have low vitamin D levels. For adults in the U.S., it’s around 35 percent. These statistics may vary because of different definitions and criteria for vitamin deficiency across studies.

According to the National Eczema Association, groups of people at risk of low vitamin D include:

• Those with an elevated body mass index (BMI), a measurement that compares a person’s weight to their height to estimate body fat
• Women
• Black Americans

Reduced sun exposure, air pollution, and decreased consumption of vitamin D-rich foods partially explain low vitamin D levels.

Low vitamin D levels are linked to a loss of bone density, which can lead to fractures and osteomalacia (soft bones). In children, a lack of vitamin D can cause a rare pediatric disease known as rickets, which causes the bones to bend.

Evaluating Vitamin D Levels

Levels of vitamin D in the body can be measured by a blood test that looks at the concentration of 25-hydroxyvitamin D in the serum. It’s called the 25-hydroxy vitamin D test.

When reviewing test results, many healthcare providers consider levels between 20 and 40 nanograms per milliliter to be ideal. However, according to a new Endocrine Society clinical practice guideline published in 2024, the answer may be more nuanced than previously thought.

According to the guidelines, vitamin D supplementation may be beneficial for certain groups of people, including those who are:

• Under 18
• Over 75
• Pregnant
• Diagnosed with diabetes

For people outside these groups, the need for supplementation is less clear, even if their vitamin D levels are below the traditional threshold.

The guideline panel concluded that further studies are needed to better define the role of vitamin D and establish optimal vitamin D levels for specific health benefits.

Vitamin D and Skin Barrier Function

The skin is made up of many types of cells, each with a specific job. One of the most important types is the keratinocyte, which makes up the majority of cells in the epidermis (outermost layer of the skin). Keratinocytes are responsible for producing vitamin D when the skin is exposed to ultraviolet (UV) light.

Some research has found connections between eczema and vitamin D deficiency.

These cells also play a vital role in wound healing and maintaining a healthy skin barrier. They help defend against harmful microbes and use vitamin D and calcium to support the creation of new skin cells and repair tissue damage.

Keratinocytes also interact closely with the immune system, helping the body respond to inflammation and injury. When their function becomes disrupted — for example, by stress, genetics, or environmental triggers — it can contribute to skin conditions like atopic eczema.

Eczema and Vitamin D Deficiency

For many years, vitamin D was primarily recognized for its role in bone health. However, more recent studies have uncovered its broader importance in processes such as immune responses and cell growth, especially within the skin.

Some research has found connections between skin conditions, such as eczema and psoriasis, and vitamin D deficiency. Because the skin barrier is disrupted in eczema, researchers have suggested that vitamin D and the cells that produce it may also play a role in eczema development. The link to psoriasis is more established, with topical vitamin D analogs commonly used as treatment for psoriasis.

While earlier studies showed mixed results, a 2024 meta-analysis found connections between vitamin D supplementation and a decreased severity of atopic dermatitis in children and adults. This conclusion suggests a potential link between vitamin D deficiency and eczema. However, more research is needed to better understand the connection and the effects of vitamin D.

A few factors might influence the association between lower vitamin D levels and eczema. For example, studies have found a higher prevalence of eczema in people who live in higher-latitude locations that get less sun exposure throughout the year. The weather in these areas can also affect eczema risk.

Genetics may also play a role. Studies have found that certain gene variants, such as those affecting the vitamin D receptor, are more common in individuals with severe atopic dermatitis. These variants can alter how the body processes vitamin D, potentially leading to lower levels of vitamin D and more severe eczema symptoms.

Does Vitamin D Help Eczema?

Although vitamin D is not currently included in clinical guidelines as a standard treatment for eczema, emerging research suggests it may offer benefits for individuals with some types of eczema.

The 2024 review and meta-analysis mentioned previously concluded that, while further research is needed, vitamin D supplements could be considered a safe and potentially helpful therapy for many people with eczema.

If you’re interested in learning more about your vitamin D levels and whether you should take a supplement, talk with your healthcare or dermatology provider. They can help determine whether vitamin D supplements would be helpful for you.

MyEczemaTeam Members on Vitamin D

Some MyEczemaTeam members have shared their experiences with taking vitamin D or other supplements to help their skin. One member said, “Started taking vitamin D for eczema and noticed that the flares are not as bad as they once were. My nights are a little more comfortable.”

Another MyEczemaTeam member shared, “It’s been two weeks since I started vitamin D and E supplements, and I’m back to my baseline level of rash! I hope this is a real improvement.”

Important Considerations Before Taking Supplements

While vitamin D supplements may offer benefits for some people with eczema, it’s essential to speak with your doctor before starting any new supplement. Your provider can help you determine the right dose — if a supplement is needed at all — based on your health history and current vitamin D levels.

Keep in mind that the U.S. Food and Drug Administration (FDA) does not regulate supplements as strictly as prescription medications. To help ensure safety and quality, look for supplements from reputable brands that follow third-party testing or certification.

Can You Overdose on Vitamin D?

Although there are many benefits to additional vitamin D when your levels are low, too much of the nutrient can become harmful. The daily U.S. recommended dietary allowance (RDA) is 600 international units (IUs) of vitamin D for people aged 19 years or older. For adults over 70, the RDA increases to 800 IUs daily.

A person can develop hypervitaminosis D (vitamin D toxicity) from taking too high a dose of supplements. This condition develops only from supplementation, not from sun exposure or diet, because the body naturally regulates those levels.

High vitamin D levels can lead to a harmful buildup of calcium in the blood, known as hypercalcemia. This can lead to symptoms such as frequent urination, vomiting, and weakness. If you continue to consume too much vitamin D, accumulation of the mineral can cause bone pain or lead to calcium stones in the kidneys.

If you begin showing signs of hypervitaminosis D, consult your doctor. They may test your blood vitamin D levels to see if the dose is too high.

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