Background: There is limited research examining the association between psoriasis, dietary intake and nutritional status in the general U.S. population.

Objective: This study aimed to compare levels of vitamins and carotenoids as well as intake of protein, fats, sugar, carbohydrates and total calories between individuals with and without psoriasis.

Methods: We used data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) in the U.S. Demographic information, physical examination, serum laboratory values and questionnaires on past medical history and dietary intake were used to determine the relationship between psoriasis and nutritional status and diet.

Results: The cohort consisted of 6260 participants who provided responses to their psoriasis status. Prior psoriasis diagnosis was reported in 156 (2.49%) of the respondents. Based on multivariate regression analysis, psoriasis was significantly associated with increased vitamin A level (OR: 1.01; CI: 1.00-1.02; P = 0.03), increased α-carotene level (OR: 1.02; CI: 1.01-1.04; P = 0.01), lower sugar intake (OR: 0.998; CI: 0.996-1; P = 0.04), increased body mass index (OR: 1.04; 95% CI: 1.02-1.07; P = 0.0003) and arthritis (OR: 2.31; CI: 1.37-3.90; P = 0.002). Non-Hispanic black (OR: 0.56; CI: 0.34-0.96; P = 0.03) and Hispanic race (OR: 0.37; CI: 0.19-0.75; P = 0.005) were inversely associated with a diagnosis of psoriasis compared with non-Hispanic white race.

Conclusion: Psoriasis is significantly associated with elevated serum levels of vitamin A and α-carotene and reduced intake of sugar. Longitudinal monitoring of nutritional status in psoriasis patients is necessary to determine the effect of nutrition on psoriasis progression and the modifying role of treatments.