Get the Facts: Vitamin D

Get the Facts

By Angela Ballard, RN

Published On: Jan 3, 2022

Last Updated On: Jan 3, 2023

For many of us, winter means shorter days, colder weather and less time spent outdoors. However, this can also mean fewer opportunities for our bodies to create essential vitamin D. In an effort to help restore balance, many people take daily supplements — but do they really work? And can taking vitamin D supplements help reduce the severity of eczema symptoms? We’re here to investigate.

Why do people take vitamin D supplements?   

Although there is still some debate, experts are increasingly suggesting vitamin D supplements for their eczema patients. To find out why, we talked to Dr. Peter Lio, Assistant Professor of Clinical Dermatology and Pediatrics at Northwestern University’s Feinberg School of Medicine and the founding director of the Chicago Integrative Eczema Center.

“In general,” Dr. Lio said, “I recommend vitamin D supplementation to my eczema patients. While I do not think that all of them are necessarily deficient, I do think that many of my patients, if not most, have a relative vitamin D insufficiency.”

Indeed, according to a National Health and Nutrition Examination Survey, 40% of adults in the United States and 61% of children under the age of 21 are low in vitamin D.1, 2 Other sources estimate that three out of four Americans and one billion people worldwide have vitamin D insufficiency.3 Groups at particular risk of having low vitamin D include women, Black Americans and anyone with an increased body mass index.4 Inadequate vitamin D (a nutrient important for immune function, bone and heart health, disease prevention and more) is believed to be due to: dietary factors; decreased time spent outdoors (the body creates vitamin D when skin is exposed to the sun); living in geographic locations where natural sunlight may be limited (especially in winter); air pollution; and not eating enough vitamin D rich foods like salmon, tuna, fortified orange juice, milk and yogurt.

Vitamin D, Dr. Lio explained, plays a number of roles in health and disease prevention. For eczema, the main factor seems to relate to immune system regulation, with research showing that vitamin D can:

·       help modulate immune responses in various inflammatory and autoimmune diseases;

·       suppress overall inflammation;

·       promote a stronger skin barrier;

·       and lessen the severity of eczema symptoms.5

Vitamin D has also been shown to impact the microbiome (which is essential for healthy skin), reduce susceptibility to bacterial and viral infections and lessen allergies.6

Interestingly, Lio notes that vitamin D supplementation may be useful for promoting overall health, as well. “Which is why I personally take a vitamin D supplement even though I don’t have eczema,” he said. Of note, adequate vitamin D has been associated with reduced risks for developing certain types of cancer, bacterial infections, rheumatoid arthritis, Crohn’s disease, periodontal disease, multiple sclerosis, cardiovascular diseases, stroke, Alzheimer’s disease, depression and more.5

How much vitamin D should you take?

Dr. Lio typically recommends 4,000 IU per day for adults. For infants and toddlers, he indicated that vitamin D drops designed for babies, generally 400 IU per day, work best; and he said that older children should take 1,000 IU per day, also as drops.

In a small study (11 participants) of children ages 2–13 with eczema, 80% of those taking 1,000 IU of vitamin per day for one month showed improvement in their symptoms. In another study with 30 participants, all of those taking 1,600 IU of vitamin D daily showed significant improvement in their eczema.5 Keep in mind, however, that too much vitamin D can be dangerous7, so stick to doses recommended by your healthcare provider or as outlined by Dr. Lio above. And, of course, before adding any supplements to your routine it’s best to consult your physician or your child’s pediatrician for an individualized approach.

Bottom line

“While there is still some confusion and disagreement in the literature,” said Dr. Lio, “there are significantly more publications supporting the use of vitamin D in atopic dermatitis, and I think that overall the conclusion is that there is an association of lower vitamin D levels with worsening eczema severity. Vitamin D supplementation does seem to have a beneficial effect on atopic dermatitis, though it is not a universal effect and is probably fairly modest in its magnitude.”


1. Parva NR, Tadepalli S, Singh P, et al. Prevalence of Vitamin D Deficiency and Associated Risk Factors in the US Population (2011-2012). Cureus. 2018;10(6):e2741. Published 2018 Jun 5.

2. Kumar J, Muntner P, Kaskel FJ, Hailpern SM, Melamed ML. Prevalence and associations of 25-hydroxyvitamin D deficiency in US children: NHANES 2001-2004. Pediatrics. 2009;124(3):e362-e370.

3. Yamamoto EA, Jørgensen TN. Relationships Between Vitamin D, Gut Microbiome, and Systemic Autoimmunity. Front Immunol. 2020;10:3141. Published 2020 Jan 21.

4. Hoffmann MR, Senior PA, Mager DR. Vitamin D supplementation and health-related quality of life: a systematic review of the literature. Journal of the Academy of Nutrition and Dietetics. 2015 Mar 1;115(3):406-18.

5. Wilchowski SM, Lio P. D as in Delta: The Changing Views of Vitamin D in Dermatology. Practical Dermatology. November 2021.

6. Palmer DJ. Vitamin D and the Development of Atopic Eczema. J Clin Med. 2015;4(5):1036-1050. Published 2015 May 20.

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