Background: Vitamin B12 is a contributing factor in pruritus and peripheral nerve regeneration. Its role in atopic dermatitis (AD) is still unclear. This study aimed to compare vitamin B12 level between AD patients and healthy controls, determine its correlation with pruritus and AD severity, and evaluate dietary pattern with energy, macro and micronutrient intakes. Methods: This was a case control study involving adult AD patients and age-, gender-, ethnicity- and body mass index-matched healthy controls. All adult patients who fulfilled UK Working Party AD diagnostic criteria were included. Exclusion criteria include patients on systemic agents, diseases known to affect B12 level and vegan diet. AD severity was determined using SCORing Atopic Dermatitis (SCORAD) index. Serum vitamin B12 level were measured. A three-day 24-hour dietary recall was collected and analyzed. Results: A total of 42 AD patients and 42 controls were recruited. Mean SCORAD index was 39.2±16.6, and AD duration was 12.7 ± 8.1 years. Vitamin B12 was lower among AD (215.6 ± 110.2 pmol/L) versus control (295.1± 119.9 pmol/L), p<0.01 despite similar dietary B12 intake in both groups. There were no significant correlations between AD duration and severity with vitamin B12 level. Energy intake (kcal/ day) was significantly lower in AD (p=0.04). There were no significant differences in proportion of main food groups consumed and other macronutrient and micronutrient intakes. Conclusion Serum vitamin B12 level was significantly lower in AD patients despite similar dietary pattern and nutrient intake with healthy controls. There were no correlations with AD severity or disease duration. Dietary pattern of AD patients should be routinely assessed to ensure adequate nutrition.
Dermatitis, Atopic--therapy ; Vitamin B12 ; Diet Therapy ; Adult