Although studies show that the intake of ultra-processed products (UPP) has a negative impact on health, diet quality and dietary vitamin D, its influence on serum concentrations of this vitamin remains unknown; therefore, it is essential to verify the association between the UPP consumption and vitamin D deficiency. This is a cross-sectional, household, population-based study, carried out with 229 individuals aged 20 years or older, residents of the city of Teresina, Piauí, Brazil. Socio-demographic, lifestyle, food consumption and anthropometric data were collected. Food consumption was obtained using a 24-h food recall, and foods were grouped according to the NOVA classification. Plasma concentrations of calcidiol-25 (OH) D3 were determined by HPLC. Crude and adjusted binary logistic regression was applied to estimate the association between UPP consumption and vitamin D deficiency. Most individuals aged 20-39 years were vitamin D deficient (52·1 %). UPP contributed 19·9 % to the energetic intake of the participant's diet. This contribution was higher for individuals with vitamin D deficiency (22·5 %, P = 0·04). In addition, a high intake of UPP was associated with twice the risk of vitamin D deficiency in comparison with low consumption of UPP (OR: 2·05; CI 1·06, 4·50; P: 0·04). Our results suggest that the consumption of UPP may have a negative impact on serum concentrations of vitamin D; more studies are needed.
Keywords: Deficiency; Food consumption; Ultra-processed foods; Vitamin D.