Vitamin D supplementation may improve eczema symptoms, researchers say

Reviewing existing studies looking at vitamin D functions in skin physiology, Qatari researchers found mounting evidence that ingesting vitamin D may help improve skin inflammatory symptoms.

In the review, published in the journal Skin Pharmacology and Physiology, the researchers wrote that “vitamin D supplementation could be promising in reducing the cutaneous [bacterial] burden in atopic dermatitis patients,” referring specifically to symptoms caused by the bacteria Staphylococcus aureus.

Though the vitamin is mostly known for its skeletal role, the researchers argued that, in recent years, its functions in different organs have been increasingly recognized.

The review compiled data from the most recent studies on vitamin D functions in skin physiology, focusing specifically on inflammatory skin conditions such as psoriasis and atopic dermatitis (eczema).

Analyzed in the study were multiple forms of vitamin D intake, from topical lotions to supplementations to regular dietary patterns.

Supplementation linked to ‘significant improvements’ of atopic dermatitis

Researchers in the present review cited about a dozen studies and meta-analyses that have linked vitamin D supplementation to “significant improvements” in atopic dermatitis severity, published between 2012 and 2016.

This includes an Italian clinical trial published in 2015, which posits that vitamin D supplementation may be an effective treatment in reducing atopic dermatitis severity in children, and a 2016 meta-analysis by Korean researchers published in Nutrition, in which the researchers say that “vitamin D has a potentially significant role for improving the symptoms of atopic dermatitis.”

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There are two forms of vitamin D: D2, also known as ergocalciferol, and D3, also known as cholecalciferol. Both forms are transformed in the liver and kidneys into 25- hydroxyvitamin D (25(OH)D), the non-active 'storage' form, and 1,25-dihydroxyvitamin D (1,25(OH)2D). Image © Getty Images / ratmaner (ratmaner/Getty Images/iStockphoto)

Another clinical trial published in 2015 showed a reduction in the skin colonization by the bacteria S. aureus and an improvement in clinical symptoms of atopic dermatitis patients, who received an oral supplementation of 2,000 IUs of vitamin D daily for 4 weeks.

Multiple mechanisms have been proposed by the many studies that have linked vitamin D supplementation to improved skin symptoms. One example is vitamin D’s inhibitory effect on the allergic response. “Vitamin D suppressed the IgE production by human B cells and dampened IgE-mediated mast cell activation in both in vitro and in vivo settings,” they reported, citing a study from 2014.

‘Could not be stated with certainty’

There have been a “myriad of studies advocating the important role of vitamin D in atopic dermatitis,” the researchers argued.

But studies addressing the relationship between vitamin D and atopic dermatitis could be hampered by the geographic, seasonal and diet-related vitamin D variations in patients and healthy controls, thus, “the relationship could not be stated with certainty.”

“So far, therapeutic interventions (topical and systemic) based on vitamin D have been proved beneficial in psoriasis and opic dermatitisat,” they added.

“Future studies are needed to mechanistically and intensely explore the specific pathways affected by vitamin D using the latest advanced technologies and to assess the safety and efficacy of vitamin D-based treatment regimens in various inflammatory skin diseases.”

Source: Skin Pharmacology and Physiology

Published online, https://doi.org/10.1159/000485132

Vitamin D and the Pathophysiology of Inflammatory Skin Diseases

Authors: Umar M., Sastry K.S., Al Ali F., Al-Khulaifi M., Wang E., Chouchane A.I.