Manual de instrumentos de evaluación dietética (Edición en español) / Dietary Assessment Resource Manual

El manual presenta, el producto del trabajo cuidadoso y fundamentado de la Dra. Frances Thompson y colaboradores, constituye una fuente de información objetiva sobre métodos de evaluación dietética, que será de interés para nutriólogos, médicos, salubristas y otros interesados en el tema. El Instituto de Nutrición de Centro América y Panamá (INCAP), pone a disposición de estudiosos de la nutrición, la salud clínica y pública, y de otros campos vinculados a la Seguridad Alimentaria y Nutricional, esta valiosa publicación, en su versión en español, que con seguridad servirá también al desarrollo de nuevos métodos y técnicas dietéticas

Ferritin concentrations in dried serum spots prepared by standard compared with simplified approaches: a validation study in Guatemala City.

BACKGROUND: Spot ferritin assay on dried serum spot (DSS) samples provides reliable and accurate assessment. Standard DSS preparations, however, involve precise serum aliquots and require some skill and training of field personnel. OBJECTIVE: We evaluated the validity of the spot ferritin assay on DSS samples prepared by simplified approaches and standard technique in Guatemala City. DESIGN: Venous blood (5 mL) was obtained from 104 subjects aged 24 +/- 15 y (x +/- SD) and transferred into nonheparin-containing (2 plain and 2 self-sealing) capillary blood collection tubes. Three DSS samples were prepared: A (standard, 20 microL serum), B (blot, approximately 30-35 mm serum column), and C (dispenser, 20 microL serum pushed directly from self-sealing capillary tubes with a dispenser). Spots were air-dried and placed in hermetic plastic bags with a desiccant. Two weeks later, entire spots for DSS A and C samples and a circle in the center for DSS B samples were analyzed. RESULTS: DSS ferritin A, B, and C correlated strongly with traditional ferritin (r = 0.71-0.88, P < 0.001). The geometric mean (-1 SD and +1 SD) values for the DSS A, B, and C and traditional ferritin methods were 27.5 (12.6, 60.2), 32.4 (13.5, 77.6), 27.5 (11.7, 64.6), and 30.2 (13.8, 66.1) microg/L, respectively, and did not differ significantly. The difference in ferritin values by various DSS approaches compared with the traditional approach was small (<4 microg/L; P > 0.05). CONCLUSIONS: Simplified and standard DSS methods provide accurate iron-status assessment in population studies. The simplified DSS approaches for serum ferritin measurement need to be evaluated further in populations in whom iron deficiency is prevalent.

Day-to-day variations in iron, zinc and copper in breast milk of Guatemalan mothers.

OBJECTIVE: To assess the within-subject and between-subject coefficients of variation (CV) of iron, zinc and copper concentrations in the milk of Guatemalan mothers. METHODS: We performed a cross-sectional study in lactating women who had delivered a healthy infant 1 to 6 months previously in two low-income peri-urban areas (San Bartolome Milpas Altas and Ciudad Peronia) and a low-income rural area (San Juan Chamelco) in Guatemala. Women infested with Ascaris lumbricoides or Trichuris trichiura received a single dose of albendazole (400 mg) or placebo. Two weeks after treatment, milk samples were collected on 3 or 4 consecutive days. Trace element concentrations in milk were measured by inductively coupled plasma/atomic emission spectrometry. RESULTS: The instrumental error of the inductively coupled plasma/atomic emission spectrometry method, expressed as SD, was 0.04, 0.27 and 0.02 mg/L for iron, zinc and copper, respectively. Concentrations in milk samples collected from 47 mothers on 3 or 4 consecutive days, expressed as mean +/- SD, were 0.28 +/- 0.13, 2.03 +/- 0.37 and 0.29 +/- 0.07 mg/L for iron, zinc and copper, respectively. The within-subject CV was 46.1%, 18.2%, and 22.8% and the between-subject CV was 61.2%, 48.3% and 31.7% for iron, zinc and copper, respectively. Stage of lactation, infestation with intestinal parasites and residential area had a significant influence on milk zinc, copper and iron concentrations. CONCLUSIONS: One sample of milk is sufficient to give a reliable estimate of the zinc concentration in milk. Two samples taken on consecutive days are required for a reliable estimate of iron and copper concentrations.

Use of the deuterated-retinol-dilution technique to monitor the vitamin A status of Nicaraguan schoolchildren 1 y after initiation of the Nicaraguan national program of sugar fortification with vitamin A.

BACKGROUND: Nicaragua initiated a national program of vitamin A fortification of its domestic sugar supply starting with the 1999-2000 sugarcane harvest. OBJECTIVE: This study was conducted to document any change in the vitamin A status of a cohort of children during the first year of the program. DESIGN: The vitamin A status of 21 Nicaraguan schoolchildren (mean age: 6.7 y; range: 5.3-9.3 y) was assessed in March 2000 and in March 2001. Total-body vitamin A stores and liver vitamin A concentrations were estimated with the deuterated-retinol-dilution (DRD) technique at a dose of 5 mg [(2)H(4)]retinyl acetate at baseline and 5 mg [(2)H(8)]retinyl acetate during the repeat test 1 y later. Plasma retinol and carotenoids were measured by HPLC. RESULTS: Median total-body vitamin A stores increased from 0.33 to 0.72 mmol (P = 0.0001), liver vitamin A concentrations from 0.52 to 0.78 mumol/g (P = 0.0003), and plasma retinol concentrations increased from 0.97 to 1.17 mumol/L (P = 0.01). CONCLUSION: The vitamin A status of Nicaraguan schoolchildren improved during the year after the initial distribution of vitamin A-fortified sugar in Nicaragua.

Patrón dietético e ingesta de nutrientes de niños pre-escolares de tres aldeas rurales del departamento de Santa Rosa, Guatemala / Dietary pattern and nutrients intake of preschool children of three rural hamlets in the Province of Santa Rosa, Guatemala

Se presentan los resultados de una evaluación nutricional encaminada a mostrar el pátron general de consumo de alimentos y la ingesta de nutrientes en 303 pre-escolares (seis a 71 meses de edad) de tres aldeas rurales de la región sur-oriental de la República de Guatemala. Esta evaluación dietética se realizó como paso previo a una intervención alimentario-nitricional en la misma área geográfica. La información dietética fue recabada entre los meses de junio a agosto de 1991 por personal del Centro de Estudios en Sensoriopatías, Senectud e Impedimentos y Alteraciones Metabólicas CeSSIAM utilizando dos instrumentos de recolección de datos, mediante entrevistas efectuadas en visitas domiciliarias. Las informantes fueron las madres o personas encargadas de la alimentación de los niños. Los datos obtenidos fueron convertidos inicialmente a pesos, y posteriormente a micronutrientes con el objetivo de compararlos con los estándares dietéticos establecidos para los niños de esas edades. Los resultados mostraron un patrón dietético en el que la tortilla de maíz y los frijoles resultaron ser los aliemntos de mayor consumo, constituyendo, a la vez, las principales fuentes de caloría, proteínas y hierro. La ingesta de vitamina A mostró una adecuación dietética bastante baja y provino, en su mayoría, de fuentes de origen vegetal. Con excepción de proteína y hierro, las ingestas de micronutrientes estuvieron por debajo de las recomendaciones dietéticas