Background: Worldwide, an estimated 250 million children <5 y old are vitamin A (VA) deficient. In Mexico, despite ongoing efforts to reduce VA de

Current dietary guidelines for breast cancer patients (BCPs) fail to address adequate dietary intakes of macro- and micronutrients that may improve pa

Background: Retinol isotope dilution (RID) methodology provides a quantitative estimate of total body vitamin A (VA) stores and is the best method currently available for assessing VA status in adults and children. The methodology has also been used to test the efficacy of VA interventions in a number of low-income countries. Infections, micronutrient deficiencies (eg, iron and zinc), liver disease, physiological age, pregnancy, and lactation are known or hypothesized to influence the accuracy of estimating total body VA stores using the isotope dilution technique. Objective: Our objectives were to review the strengths and limitations of RID methods, to discuss what is known about the impact of various factors on results, and to summarize contributions of model-based compartmental analysis to assessing VA status. Methods: Relevant published literature is reviewed and discussed. Results: Various equations and compartmental modeling have been used to estimate the total body VA stores using stable isotopes, including a newer 3-day equation that provides an estimate of total body VA stores in healthy adults. At present, there is insufficient information on absorption of the isotope tracer, and there is a need to further investigate how various factors impact the application of RID techniques in field studies. Conclusions: Isotope dilution methodology can provide useful estimates of total body VA stores in apparently healthy populations under controlled study conditions. However, more research is needed to determine whether the method is suitable for use in settings where there is a high prevalence of infection, iron deficiency, and/or liver disease.

Vitamin A (VA) deficiency (VAD) continues to be a major nutritional problem in developing countries, including Central America. In Mexico, milk is a

Alcalase is the enzyme of choice to release antihypertensive peptides from amaranth proteins, but the hydrolysis conditions have not been optimized yet. Furthermore, in vivo assays are needed to confirm such a hypotensive effect. Our aim was to optimize the hydrolysis of amaranth protein with alcalase and to test in vivo the hypotensive effect of the hydrolysates. A response surface analysis was carried out to optimize the hydrolysis reaction. The response variable was the Angiotensin Converting Enzyme (ACE-I) inhibition. The hydrolysis degree was determined (free alpha-amino groups measurement). The optimized hydrolysate bioavailability was assessed in the sera of mice and the hypotensive effect was assessed in spontaneously hypertensive rats. Control groups were administered captopril or water. The optimized hydrolysis conditions were: pH = 7.01, temperature = 52 °C, enzyme concentration 0.04 mU/mg, and time = 6.16 h. The optimized hydrolysate showed a 93.5% of ACE-I inhibition and a hydrolysis degree of 74.77%. After supplementation, the hydrolysate was bioavailable in mice from 5 to 60 min, and the hypotensive effect started at 4 h in spontaneously hypertensive rats (p < 0.05 vs. water group). This effect was similar to the captopril hypotensive effect for the next 3 h (p > 0.05). The use of amaranth-optimized hydrolysates as hypotensive supplements or ingredient for functional foods seems feasible.

Background: Vitamin A deficiency (VAD) is a nutritional problem affecting the health of people in developing countries because VAD compromises innate and adaptive immunity, increasing a person’s predisposition toward infectious diseases. In addition, a high prevalence of infectious diseases continues to be a problem in developing countries, including Giardia lamblia. G. lamblia may be related to VAD because of its ability to change the intestinal architecture, thereby compromising the absorption of vitamin A. The aim of this study was to evaluate the effect of giardiasis on serum retinol levels and vitamin A liver stores in school children. Methods: Thirty Giardia-infected school children participated in this study. Vitamin A liver stores were evaluated with the modified relative dose response (MRDR) technique, and antiparasitic treatment was administered. In addition, anthropometric and dietary data were collected. Results: According to anthropometric indicators (age-appropriate Z scores for weight, height and body mass index) and daily vitamin A intake, the children had a normal nutritional status. Although the mean serum retinol levels did not change significantly after treatment for Giardia (p > 0.05), the MRDR values showed significant improvement (p < 0.002). Conclusion: Giardiasis not only compromises the vitamin A status through intestinal malabsorption, it also causes profound mobilization of liver retinol stores.