Serum 25-hydroxyvitamin D concentration among users of a referral outpatient unit for vascular diseases and associated factors.

Objective: Assess serum 25-hydroxyvitamin D (25OHD) concentration and associated factors among users of a referral outpatient unit for vascular diseases in Southern Brazil.

Design: Cross-sectional study conducted for almost one year, from March 2016 to January 2017. The serum vitamin D level was determined biochemically and classified as: sufficient (>50 nmol/L), insufficient (30-50 nmol/L) and deficient (<30 nmol/L).

Vitamin D serum levels and peripheral arterial disease among southern Brazilian adults.

Objective: To investigate the association between low serum vitamin D levels and peripheral arterial disease (PAD).

Methods: A cross-sectional study with a consecutive sample of 133 individuals from Caxias do Sul, Brasil. We considered PAD patients those with an ankle-brachial index (ABI) ≤ 0.

[Reproducibility, relative validity, and calibration of a food-frequency questionnaire for adults in Greater Metropolitan Porto Alegre, Rio Grande do Sul State, Brazil].

This study tested the relative validity and estimated calibration factors of a food-frequency questionnaire (FFQ) with 120 food items in 128 adults. We applied one FFQ and three 24h recalls. Validity was tested by the Bland-Altman method, intraclass correlation coefficient (ICC), classification in quartile categorization, and weighted kappa.