Clinical and Vitamin Response to a Short-Term Multi-Micronutrient Intervention in Brazilian Children and Teens: From Population Data to Interindividual Responses.

SCOPE: Micronutrients are in small amounts in foods, act in concert, and require variable amounts of time to see changes in health and risk for disease. These first principles are incorporated into an intervention study designed to develop new experimental strategies for setting target recommendations for food bioactives for populations and individuals. METHODS AND RESULTS: A 6-week multivitamin/mineral intervention is conducted in 9-13 year olds. Participants (136) are (i) their own control (n-of-1); (ii) monitored for compliance; (iii) measured for 36 circulating vitamin forms, 30 clinical, anthropometric, and food intake parameters at baseline, post intervention, and following a 6-week washout; and (iv) had their ancestry accounted for as modifier of vitamin baseline or response. The same intervention is repeated the following year (135 participants). Most vitamins respond positively and many clinical parameters change in directions consistent with improved metabolic health to the intervention. Baseline levels of any metabolite predict its own response to the intervention. Elastic net penalized regression models are identified, and significantly predict response to intervention on the basis of multiple vitamin/clinical baseline measures. CONCLUSIONS: The study design, computational methods, and results are a step toward developing recommendations for optimizing vitamin levels and health parameters for individuals.

Determination of folate in infant formula and adult/pediatric nutritional formula by ultra-high performance liquid chromatography-tandem mass spectrometry: First Action 2013.13.

A UHPLC-MS/MS method for the determination of folate (vitamin B9) in infant formula and adult/pediatric nutritional formula was assessed for compliance with standard method performance requirements set forth by the AOAC INTERNATIONAL Stakeholder Panel for Infant Formula and Adult Nutritionals (SPIFAN). A single-laboratory validation (SLV) study was conducted as the first step in the process to validate the method. In the study, 12 matrixes, representing the range of infant and adult nutritional products, were evaluated for folate [the sum of supplemental folic acid plus 5-methyl tetrahydrofolic acid (5-Me THF)]. Method response was linear in the range of 1.0-900 ng/mL, corresponding to 0.33-300 microg/l100 g in reconstituted sample. LOD for folic acid and 5-Me THF, expressed in reconstituted product, were 0.10 microg/100 g and 0.05 microg/100 g, respectively, and LOQ were 0.33 microg/100 g and 0.10 microg/100 g, respectively. Repeatability was <5.3% and intermediate precision was <5.5%. Recovery rates of spiking at 50 and 100% of target values in nonfortified products were within 90-110%. Evaluation of trueness was performed on Certified Reference Material (SRM 1849 Infant/Adult Nutritional Formula) and gave 96.4% of theoretical value. Based on the results of the SLV, the method meets the SPIFAN requirements for AOAC First Action status for the determination of folates in infant formula and adult/pediatric nutritional formula.

Choline in infant formula and adult/pediatric nutritional Formula by ultra high-performance liquid chromatography/ Tandem mass spectrometry: AOAC First Action 2012.18.

The method described below is for the determination of choline in infant formula and adult/pediatric nutritional formula by ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The single-laboratory validation data were submitted to the Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) Expert Review Panel (ERP) for review at the AOAC INTERNATIONAL Annual Meeting held September 30 to October 3, 2012 in Las Vegas, NV. The ERP determined that the data reviewed met the standard method performance requirements set by SPIFAN, and the method was approved as AOAC Official First Action. The analytical range was found to be between 0.16 and 3.2 microg/mL. The recovery rates were within 80-120% at 50 and 100% of native levels for all samples. Repeatability precision (RSDr) was < 3%, with intermediate reproducibility (RSDir) no higher than 4%.

Determination of vitamin B12 in infant formula and adult nutritionals by liquid chromatography/UV detection with immunoaffinity extraction: First Action 2011.08.

At the "Standards Development and International Harmonization: AOAC INTERNATIONAL Mid-Year Meeting," on June 29, 2011, an Expert Review Panel agreed that the method "Determination of Vitamin B12 in Infant Formulas and Adult Nutritionals by Liquid Chromatography/UV Detection with Immunoaffinity Extraction" be adopted AOAC Official First Action status. The method is applicable for the determination of vitamin B12, which includes added cyanocobalamin and natural forms, making it applicable to both fortified and nonfortified products. Vitamin B12 is extracted from the sample in sodium acetate buffer in the presence of sodium cyanide (100 degrees C, 30 min). After purification and concentration with an immunoaffinity column, vitamin B12 is determined by LC with UV detection (361 nm). A single-laboratory validation study was conducted on a range of products, including milk- and soy-based infant formulas, cereals, cocoa beverages, health care products, and polyvitamin premixes. The method demonstrated linear response over a large range of concentrations, recovery rates of 100.8 +/- 7.5% (average +/- SD), repeatability RSD (RSDr) of 2.1%, and intermediate reproducibility (RSD(iR)) of 4.3%. LOD and LOQ values were 0.10 and 0.30 microg/100 g, respectively, and correlation with the reference microbiological assay was good (R2 = 0.9442). The results of the study were published in J. AOAC Int. 91, 786-793 (2008). The performance characteristics of the method met the standard method performance requirements set forth by the Stakeholder Panel on Infant Formula and Adult Nutritionals; thus, the method was determined to be appropriate for First Action status.

Determination of vitamin B12 in food products by liquid chromatography/UV detection with immunoaffinity extraction: single-laboratory validation.

A fast and simple method to determine vitamin B12 in foods is presented. The method allows, in addition to the determination of added cyanocobalamin, the determination of natural vitamin B12 forms, making it also applicable to nonfortified products, especially those that are milk-based. Vitamin B12 is extracted in sodium acetate buffer in the presence of sodium cyanide (100 degrees C, 30 min). After purification and concentration with an immunoaffinity column, vitamin B12 is determined by liquid chromatography with UV detection (361 nm). The method has been validated in analyses of a large range of products: milk- and soy-based infant formulas, cereals, cocoa beverages, health care products, and polyvitamin premixes. The method showed appropriate performance characteristics: linear response over a large range of concentrations, recovery rates of 100.8 +/- 7.5% (average +/- standard deviation), relative standard deviation of repeatability, RSDr, of 2.1%, and intermediate reproducibility, RSDiR, of 4.3%. Limits of detection and quantitation were 0.10 and 0.30 microg/100 g, respectively, and correlation with the reference microbiological assay was good (R2 = 0.9442). The proposed method is suitable for the routine determination of vitamin B12 in fortified foods, as well as in nonfortified dairy products. It can be used as a faster, more selective, and more precise alternative to the classical microbiological determination.