Validity of a questionnaire to estimate vitamin A intake in pregnant women

The objective was to assess the relative validity of a food frequency questionnaire (FFQ) to estimate daily vitamin A intake in pregnant women using two biomarkers as references, maternal serum retinol and breast milk retinol. This is an observational, descriptive, analytical, cross-sectional study. FFQ was applied to 161 pregnant women at the largest public maternity hospital in Ribeirão Preto, Brazil. The FFQ recall period was the last 30 days before childbirth. The mother was asked if she had consumed or not each food item over the last 30 days, how often and which portion size. Samples of maternal blood and breast milk for determination of retinol concentrations were collected. Partial Pearson correlation test, agreement by kappa quadratic statistics, cross-classification into quartiles and the method of triads with two biomarkers were performed. The mean FFQ intake of vitamin A was 875 µg/day and the frequency of inadequate intake was 52.8%. Low correlation coefficients were observed between the FFQ and both biomarkers. In cross-classification, considering foods sources with or without provitamin A, 63.6% to 68.3% of the results fell into the same or adjacent quartiles, respectively; less than 10% of all results were classified into opposite quartiles. The validity coefficient of the FFQ was 0.484. FFQ performed better when considering only food sources of preformed vitamin A and both biomarkers (ρ=0.554). As a conclusion, FFQ provided an estimate of vitamin A intake with moderate accuracy, being suitable to rank pregnant women according to categories of intake(AU)

O objetivo foi avaliar a validade relativa de um Questionário de Frequência Alimentar (QFA) para estimar o consumo de vitamina A em mulheres grávidas usando dois biomarcadores como referência, retinol sérico materno e retinol de leite materno. Trata-se de um estudo observacional, descritivo, analítico e transversal. O QFA foi aplicado a 161 gestantes na maior maternidade pública de Ribeirão Preto. O período de abrangência do QFA foi de 30 dias antes do parto. Questionava-se à mãe se ela havia ingerido ou não cada item de alimento contido em um álbum fotográfico nos últimos 30 dias e qual era a frequência e o tamanho da porção consumida. Foram coletadas amostras de sangue materno e leite materno para determinação das concentrações de retinol. Foi realizado o teste de correlação parcial de Pearson, concordância de kappa, classificação cruzada em quartis e o método de tríades com dois biomarcadores. A ingestão média pelo QFA de vitamina A foi de 875mg / dia e a frequência de ingestão inadequada foi de 52,8%. Baixos coeficientes de correlação foram observados entre o QFA e ambos os biomarcadores. Na classificação cruzada, considerando fontes de alimentos com ou sem provitamina A, 63,6% a 68,3% dos resultados caíram no mesmo quartil ou adjacentes, respectivamente; Menos de 10% de todos os resultados foram classificados em quartis opostos. O coeficiente de validade do QFA foi de 0,484. O QFA apresentou melhor desempenho quando considerou apenas fontes alimentares de vitamina A pré-formada e ambos os biomarcadores (ρ = 0,554). A acurácia do QFA para a estimativa de vitamina A foi considerada moderada, sendo adequado para categorizar as gestantes em categorias de consumo(AU)

Changes in intestinal permeability and nutritional status after cytotoxic therapy in patients with cancer.

Damage to intestinal mucosa may impair nutritional status and increase the demand for nutrients involved in intestinal cell proliferation (retinol and folate). It is still unclear if cytotoxic therapy affects serum concentrations of these nutrients in patients with cancer and if this would be associated with disturbances of intestinal mucosa. Intestinal permeability, serum folate, and retinol and nutritional status of 22 patients with hematologic malignancies and 17 healthy volunteers [control group (CG)] were assessed before (T0) and after cytotoxic therapy (T1). Ingestion of lactulose and mannitol was used to assess intestinal permeability. Anthropometric, body composition, phase angle (PA), and biochemical analysis (albumin, retinol, and folate) were also performed. Lactulose/mannitol ratio (0.026 ± 0.014 vs. 0.052 ± 0.037) and lactulose excretion (0.27 ± 0.18% vs. 0.53 ± 0.6%) increased at T1. PA decreased (7.2 ± 1.9° vs. 6.2 ± 0.9°). Serum folate and albumin (20.7 ± 9.5 nmol/L, 37.7 ± 5.5 g/L) were lower than CG (39.2 ± 16.4 nmol/L, 42.9 ± 5.2 g/L) but did not change at T1 (17.5 ± 7.0 nmol/L, 35.9 ± 4.5 g/L). Serum retinol did not differ from CG and did not change at T1 (1.83 ± 0.30 µmol/L vs. 1.69 ± 0.3 µmol/L; CG: 1.86 ± 0.20 µmol/L). Abnormal intestinal permeability, low serum folate levels, and its possible relationship with intestinal alterations, and reduced PA, may be associated with poor nutritional status in cancer patients.