Dietary sources of vitamin A, C, E and beta-carotene in a adult Mediterranean population

OBJECTIVE: Estimation of vitamin A, C, E and beta-carotene food sources, as well as its nutritional intake and density in adult Catalonian population. METHODOLOGY: A cross-sectional study was conducted over 2,346 individuals obtained from the sample of Catalonian Survey of Nutritional Status aged 18 to 75 years old to estimate usual dietary intake of vitamins A, C, E and beta-carotene using two 24 hour dietary recalls administered in two periods (june-july and november-december of 1992). Replicated 24 hour Recalls allowed for estimation of usual intake. Calculation of food sources for vitamins encompassed three phases: foods transformation into nutrients, aggregation of foods in categories and sum of nutrients by food categories. RESULTS: Intake of vitamin A (equivalents of retinol of provitamin A and vitamin A), E, C were closely near or higher than RDA. Nutritional density of vitamin C, E and beta-carotene were higher in female group. Nutritional density was positively associated to age for vitamins C, E and beta-carotene. Addition fat was the first source of vitamin E and it reached 33.8% of total vitamin E intake. Vegetables contributed in 17.3 % to the total vitamin C, whereas fruits accounted for 57.9%. Fruits recached 40.6% of the total beta-carotene intake, whereas vegetables accounted for 34.8%. The major contributors of vitamin A were milk and dairy products. CONCLUSIONS: Nutritional intake of vitamin A, C and E are over the RDA parameters suggesting an healthy nutritional status that must be confirmed and ratify by biochemical assessment. Nutritional densities were higher in female gender than in males in vitamins C, E, and beta-carotene possibly due to a higher intake of total lipids in male gender than in females. Nutritional density was positively associated to age in the same group of vitamins, suggesting a higher intake of empty calories in younger group. Fruits and Vegetables accounted for more than 70% of vitamin C and beta-carotene and major contributors were citrics, carrots, tomatoes, spinach, and cauliflower, highlighting their importance in elaboration of dietary guide lines.     

Improved immunogenicity of a core-coated tetanus toxoid delivery system.

A new microparticulate delivery system composed of a stabilizing gelatin/poloxamer microcore surrounded by a PLGA coat was designed to improve the stability of tetanus toxoid (TT) encapsulated in PLGA microspheres. Microcores were prepared by a spray-congealing technique and encapsulated within PLGA using an oil-in-oil (o/o) solvent evaporation technique. SEM analysis of the cross-sections of the microcapsules revealed the adequate encapsulation of the cores, showing an intimate contact between the core and the coating. This structure was responsible for an osmotic phenomenon observed in vitro, which led to the release of the encapsulated TT in a short period of time. Nevertheless, it was observed that the release was affected by the presence of the poloxamer in the core: microspheres without poloxamer in the core exhibit a faster release (2 h) than those that incorporate the surfactant (24 h). The in vivo evaluation of this system showed that the encapsulated toxoid induced a low but continuous levels of neutralizing antibodies (Nt), whereas those obtained for the control (aluminum phosphate-adsorbed toxoid) decreased after reaching the maximum level at 14 weeks. Moreover, the administration of a mixture of encapsulated and adsorbed TT led to significant higher and more prolonged Nt levels than those measured for the adsorbed toxoid.