Vitamin D deficiency is known to decrease bone strength and heighten the risk of fractures and infections. Researchers have now identified a significant link between low levels of vitamin D and the incidence of eczema in young children.

Eczema, also known as atopic dermatitis, is a chronic skin condition characterized by redness, inflammation, itchiness, and irritation. While it commonly starts during childhood, it can manifest in individuals of any age.

In a study published in the World Allergy Organization Journal, researchers from Chang Gung University in Taiwan explored the link between vitamin D serum levels and allergen sensitization. Allergen sensitization occurs when the body develops IgE antibodies to allergens that are ingested, absorbed, or inhaled. The study also examined how this link influences the likelihood of developing atopic dermatitis in young children.

"Vitamin D deficiency is strongly associated with a heightened prevalence of allergen sensitization, potentially increasing the susceptibility to atopic dermatitis in early childhood," the researchers wrote.

The study involved a total of 222 children, including those with atopic dermatitis and age-matched healthy children without the condition or other allergic diseases. The participants were of three age groups: six months, two years, and four years.

Among children who were six months old, 59 had atopic dermatitis, and 36 were healthy. In the group with two-year-olds, 37 had atopic dermatitis, 29 were healthy, while 32 children had atopic dermatitis, and 29 were healthy in the four-year-old group.

The serum samples of all the participants were collected and tested for vitamin D, total IgE levels, and allergen-specific IgE levels. Based on their vitamin D levels, children were divided into three groups: those less than 20 ng/ml, those between 20 ng/ml to 30 ng/ml, and those greater than 30 ng/ml.

Among children at six months and 4 years old, those with less than 20 ng/ml of vitamin D had more exclusive breastfeeding and maternal atopy than those with a vitamin D level of more than 30 ng/ml. Atopy refers to the genetic tendency to develop allergic diseases including allergic rhinitis, asthma, and atopic dermatitis.

Kids with atopic dermatitis had lower vitamin D levels at 2 and 4 years old. However, more vitamin D supplementation was noted in the children with eczema at the age of six months compared to healthy kids at the same age.

The researchers also noted that food allergen sensitivity was higher in children with atopic dermatitis at 0.5 and 4 years old, while mite and IgE sensitivity were higher at 2 and 4 years old.

Food allergies and maternal atopy were identified as the biggest risk factors for atopic dermatitis in 6-month-old kids. However, for those at 2 and 4 years old, the main risk factors were vitamin D levels and mite allergy sensitization.