Vitamin D and Childhood Eczema

Childhood atopic dermatitis (eczema) affects ~15-20% of children. Vitamin D deficiency associates with more severe eczema and worse winter flares. The Camargo Mongolia RCT was the landmark evidence showing supplementation can meaningfully improve winter-associated childhood eczema.

The Camargo Mongolia trial

Camargo 2014 randomised 107 Mongolian children (aged 2-17) with winter-related eczema to 1,000 IU/day cholecalciferol or placebo for 1 month. The vitamin D group had significantly greater SCORAD (Scoring Atopic Dermatitis) improvement — 29% reduction vs 16% placebo. The trial specifically targeted winter — the vitamin D-scarce season in Mongolia — where synthesis is essentially zero.

Broader evidence

• Sidbury 2008 — small crossover in children; benefit in deficient subgroup.
• 2016 pediatric meta-analysis — pooled SCORAD reduction favouring vitamin D.
• 2020 Cochrane update — moderate-certainty evidence for benefit in patients starting deficient.

Standard eczema care

1. Daily emollients — cornerstone of care, twice daily minimum.
2. Low-potency topical steroid for face and folds; medium-potency for body.
3. Topical calcineurin inhibitors (tacrolimus, pimecrolimus) for maintenance.
4. Dupilumab or JAK inhibitors for moderate-severe unresponsive disease.
5. Address bacterial superinfection (bleach baths, topical/oral antibiotics as needed).
6. Vitamin D correction if deficient — reasonable adjunct.

Practical dosing for kids with eczema

• Infant with eczema: 400 IU/day cholecalciferol drops (standard AAP dosing).
• Ages 1-10: 600-1,000 IU/day; up to 2,000 IU/day if documented deficient.
• Adolescents: 1,000-2,000 IU/day.
• Take with a fat-containing meal for best absorption.