Jeanne Rader

Data from the National Health and Nutrition Examination Surveys. Very large increases in blood folate levels of the U.S. population occurred between 1988-1994 and 1999-2000. Small fluctuations in blood folate levels occurred over the time period 1999-2006. The median red blood cell (RBC) folate level of the U.S. population 4 years of age and older was 266 ng/mL in 2005-2006. The median serum folate level of the U.S. population 4 years of age and older was 12.2 ng/mL in 2005-2006. In 2005-2006, the prevalence of low RBC folate (less than 140 ng/mL) among U.S. women of childbearing age (15-45 years) was 4.5%. In 2005-2006, the prevalence of low serum folate (less than 3 ng/mL) among U.S. women of childbearing age was 0.5%. Folate is an essential vitamin for good health. Women of childbearing age are among the population subgroups that have been shown previously to have low blood folate levels. Low blood folate levels are associated with an increased risk of neural tube birth defects. Beginning in 1998, the Food and Drug Administration (FDA) required the addition of folic acid (a form of folate) to all enriched breads, cereals, flours, corn meal, pasta products, rice, and other cereal grain products sold in the United States. Blood folate data from the National Health and Nutrition Examination Surveys (NHANES) have documented improvements in the folate status of the U.S. population after folate fortification was implemented. Red blood cell (RBC) folate measures long-term folate intake and low levels are associated with adverse health effects. Serum folate reflects recent folate intake and low levels are an early indicator of inadequate folate status. Pre- and postfortification blood folate levels of the U.S. population 4 years of age and older and prevalence of low blood folate among women of childbearing age (15-45 years) are reported.All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as to source, however, is appreciated.

The initial nutritional status of experimental animals can influence their response to subsequent dietary regimens. In the present study, we determined the variations in minerals in diet NIH-31, a breeding colony stock diet, and in tissues of weanling rats nursed by dams fed this diet. Inductively coupled plasma-atomic emission spectrometry (ICP-AES) was used to determine nine elements (Ca, Cu, Fe, K, Mg, Mn, Na, P and Zn) in diet and in liver, kidney, spleen, duodenum and femur from 22- to 26-day-old rats. Wet digestions were performed in mixtures of nitric, perchloric, and sulfuric acids (diets and soft tissues) or nitric and perchloric acids (femur). Solution concentrations ranged from less than 25 ng/ml for the trace elements to greater than 100 micrograms/ml for the major elements. Large variations in mineral content were found between batches of commercially prepared NIH-31 diet; relative amounts of Cu, Fe, Mn and Zn varied markedly. Significant differences in concentrations of major and trace minerals in liver, kidney, spleen and duodenal tissue were found among groups of weanling rats obtained from the same supplier at different times. Mn was readily quantitated in all tissues except spleen, where it was below detection limits. The precision obtained with the ICP-AES methodology has significant advantages for establishing variations in tissue mineral levels.

Weanling male Holtzman rats were fed calcium.deficient, phosphorus-deficient, or control diets for 8 wk. Parathyroid hormone (PTH) was measured by radioimmunoassay, and 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) by a competitive binding assay. Rats fed the calcium-deficient diet (0.01% calcium, 0.6% phosphorus) became mildly hypocalcemic after 6 days. Serum calcium levels reached 5.5 +/- 0.4 mg/dl (mean +/- SD) in 5 wk (control 10.3 +/- 0.4 mg/dl). PTH increased from 285 +/- 112 to 3658 +/- 428 pg/ml within 6 wk. Maximum serum levels of 1,25(OH)2D3 (111.8 +/- 17.3 vs. control 11.4 +/- 3.8 ng/dl) were reached at 3 wk and thereafter declined to 44.6 +/- 14.0 ng/dl. In rats fed the phosphorus-deficient diet (0.6% calcium, 0.04% phosphorus), serum phosphorus fell within 24 h from 9.1 +/- 0.6 to 3.2 +/- 0.1 mg/dl, recovered to 5.6 +/- 0.4 mg/dl for 2-3 days, and then declined again. Serum calcium reached a maximum of 14.4 +/- 0.4 mg/dl at day 2 (control 10.8 +/- 0.5 mg/dl) and then slowly declined. PTH decreased within 24 h from 243 +/- 59 to 36 +/- 0 pg/ml in phosphorus-depleted rats. Serum levels of 1,25(OH)2D3 increased within 24 h and remained elevated after 6 wk of phosphorus deprivation (61.2 +/- 11.7 ng/dl vs. control 18.3 +/- 0.4 ng/dl).

In 1996, the U.S. Food and Drug Administration issued a regulation requiring that all enriched cereal-grain products be fortified with folic acid by January 1998. An average increase in folic acid intake of 100 micro g/d was projected as a result of this fortification. The objective of the present study was to estimate the effect of this fortification on the intake of folic acid and total folate, and on the prevalence of individuals with inadequate folate intake and with high folic acid intake. We used data on food and nutrient intake from 1480 individuals who participated in the 5th and 6th examinations of the Framingham Offspring Cohort Study. Fortification was instituted during the 6th examination so that 931 participants were examined before its implementation (nonexposed) and 549 after implementation (exposed). Published data on total folate in enriched cereal-grain products were used to correct folate content in these foods to reflect fortification. Among nonsupplement users, folic acid intake increased by a mean of 190 [95% confidence interval (CI): 176, 204] micro g/d (P < 0.001) and total folate intake increased by a mean of 323 (95% CI: 296-350) micro g dietary folate equivalents (DFE)/d (P < 0.001) in the exposed participants. Similar increases were seen among supplement users exposed to fortification. The prevalence of exposed individuals with total folate intake below the estimated average requirement (320 micro g DFE/d) decreased from 48.6% (95% CI: 44.2-53.1%) before fortification to 7.0% (95% CI: 3.1-10.9%) after fortification in individuals who did not use folic acid supplements. This prevalence was approximately 1% or less for users of supplements both before and after fortification. Prevalence of individuals with folic acid intake above the upper tolerable intake level (1000 micro g folic acid/d) increased only among supplement users exposed to fortification (from 1.3 to 11.3%, P < 0.001). No changes in folic acid intake were observed over time in the nonexposed participants. By these estimations, folic acid fortification resulted in a mean increase in folic acid intake that was approximately twice as large as previously projected.

Twelve powdered and 13 liquid infant formulas were analyzed by using an extension of AOAC Official Method 996.01 for fat analysis in cereal products. Samples were hydrolyzed with 8 N HCl and extracted with ethyl and petroleum ethers. Fatty acid methyl esters were prepared by refluxing the mixed ether extracts with methanolic sodium hydroxide in the presence of 14% boron trifluoride in methanol. The extracts were analyzed by gas chromatography. In powdered formulas, saturated fatty acid (SFA) content (mean +/- SD; n = 12) was 41.05 +/- 3.94%, monounsaturated fatty acid (MUFA) content was 36.97 +/- 3.38%, polyunsaturated fatty acid (PUFA) content was 20.07 +/- 3.08%, and total trans fatty acid content was 1.30 +/- 1.27%. In liquid formulas, SFA content (mean +/- SD; n = 13) was 42.29 +/- 2.98%, MUFA content was 36.05 +/- 2.47%, PUFA content was 20.65 +/- 2.40%, and total trans fatty acid content was 0.88 +/- 0.54%. Total fat content in powdered formulas ranged from 4.4 to 5.5 g/100 kc...

In 1996, U.S. Food and Drug Administration regulations mandated the fortification of enriched cereal-grain products with folic acid, thereby emphasizing the need for validated methods for total folates in foods, particularly cereal products. The AOAC Official Methods (944.12, 960.46) currently used for the analysis of folate in foods for compliance purposes are microbiological methods. When the fortification regulations were finalized, no Official AOAC or Approved AACC methods for folate in cereal-grain products were in place. The AOAC Official Method (992.05) for folic acid in infant formula does not incorporate important improvements in the extraction procedure and was not considered suitable for the analysis of folates in foods in general. A microbiological assay protocol using a trienzyme extraction procedure was prepared and submitted for comments to 40 laboratories with recognized experience in folate analysis. On the basis of comments, the method was revised to have the conju...

The initial nutritional status of experimental animals can influence their response to subsequent dietary regimens. In the present study, we determined the variations in minerals in diet NIH-31, a breeding colony stock diet, and in tissues of weanling rats nursed by dams fed this diet. Inductively coupled plasma-atomic emission spectrometry (ICP-AES) was used to determine nine elements (Ca, Cu, Fe, K, Mg, Mn, Na, P and Zn) in diet and in liver, kidney, spleen, duodenum and femur from 22- to 26-day-old rats. Wet digestions were performed in mixtures of nitric, perchloric, and sulfuric acids (diets and soft tissues) or nitric and perchloric acids (femur). Solution concentrations ranged from less than 25 ng/ml for the trace elements to greater than 100 micrograms/ml for the major elements. Large variations in mineral content were found between batches of commercially prepared NIH-31 diet; relative amounts of Cu, Fe, Mn and Zn varied markedly. Significant differences in concentrations o...

Monitoring the folate status of US population groups over time has been a public health priority for the past 2 decades, and the focus has been enhanced since the implementation of a folic acid fortification program in the mid-1990s. We aimed to determine how population concentrations of serum and red blood cell (RBC) folate and serum vitamin B-12 have changed over the past 2 decades. Measurement of blood indicators of folate and vitamin B-12 status was conducted in approximately 23,000 participants in the prefortification third National Health and Nutrition Examination Survey (NHANES III; 1988-1994) and in approximately 8000 participants in 3 postfortification NHANES periods (together covering 1999-2004). Serum and RBC folate concentrations increased substantially (by 119-161% and 44-64%, respectively) in each age group in the first postfortification survey period and then declined slightly (by 5-13% and 6-9%, respectively) in most age groups between the first and third postfortifi...

Data from the National Health and Nutrition Examination Surveys. Very large increases in blood folate levels of the U.S. population occurred between 1988-1994 and 1999-2000. Small fluctuations in blood folate levels occurred over the time period 1999-2006. The median red blood cell (RBC) folate level of the U.S. population 4 years of age and older was 266 ng/mL in 2005-2006. The median serum folate level of the U.S. population 4 years of age and older was 12.2 ng/mL in 2005-2006. In 2005-2006, the prevalence of low RBC folate (less than 140 ng/mL) among U.S. women of childbearing age (15-45 years) was 4.5%. In 2005-2006, the prevalence of low serum folate (less than 3 ng/mL) among U.S. women of childbearing age was 0.5%. Folate is an essential vitamin for good health. Women of childbearing age are among the population subgroups that have been shown previously to have low blood folate levels. Low blood folate levels are associated with an increased risk of neural tube birth defects. ...

The Hildebrand grid nebulizer (HGN) was used for the inductively coupled plasma atomic emission spectrometric determination of major, minor and trace elements in perchloric acid digests of rodent femurs, sulphuric acid digests of rodent soft tissues and in solutions leached from foodware using acetic acid. The HGN performed well when the signal-to-background ratio was optimized for each acid solution by adjusting the injector gas flow, solution uptake rate and observation height. Three problems were overcome while using the HGN: (i) nebulizer wash-out time was reduced by rinsing at high uptake rate with the solution to be analysed; (ii) clogging of the injector tip of the torch during femur analysis was minimized by extensive rinsing; and (iii) errors due to the suppression of the Cu, Fe, Mn and Zn signal intensities by matrix elements Ca and P in femur digests were eliminated by calibrating the spectrometer with matched matrix standard solutions. Overall, the precision of analysis for the leach and tissue solutions analysed in this study ranged from 0.5 to 2.9% relative standard deviation.

On July 11, 2003, the U.S. Food and Drug Administration published a final rule amending its food-labeling regulations to require that trans FA be declared in the nutrition label of conventional foods and dietary supplements. The effective date of this final rule is January 1, 2006. This places some urgency on increasing the number and types of currently available foods for which there are trans-fat data. Compositional databases on trans fat content of food are currently limited. The purpose of this study was to determine the trans-fat content of a wide range of foods prior to the effective date of the new regulation. AOAC Official Method of Analysis 996.01 was modified for the analysis of trans fat in noncereal products. Food products for analysis were selected on the basis of market share and data from the USDA's 1994-1996 Continuing Survey of Food Intake by Individuals. Foods were purchased from local supermarkets, weighed, hydrolyzed, converted to FAME, and analyzed by GC. The results showed that trans fat (g/100 g fat) ranged from 0.0 to 48.8 in bread, cake, and related products; from 14.9 to 27.7 in margarines; from 7.7 to 35.3 in cookies and crackers; from 24.7 to 38.2 in frozen potatoes; from 0.0 to 17.1 in salty snacks; from 0.0 to 13.2 in vegetable oils and shortenings; from 0.0 to 2.2 in salad dressings and mayonnaises; and from 0.0 to 2.0 in dry breakfast cereals. Serving sizes for the foods included in this survey ranged from 12 to 161 g, and trans-fat levels ranged from 0.0 to 7.2 g/serving. The significant differences in trans-fat content in products within each food category are due to differences in the type of fats and oils used in the manufacturing processes.

Simultaneous separation of steviol and steviol glycosides is challenging because of differences in their polarity and chemical structure. In this study, simultaneous analysis of steviol and steviol glycosides was achieved by LC with UV detection using a mixed-mode RP weak anion exchange chromatography column. Steviol and seven steviol glycosides were analyzed on an Acclaim Mixed-Mode Wax-1 (Dionex) column with a linear gradient of deionized water adjusted to pH 3.00 with phosphoric acid and acetonitrile. The extraction was performed by sonicating dry plant material at 40 degreesC in acetonitrile-water (30 + 70, v/v). LOQ values (mg/g dry weight of plant material) were rebaudioside B, 0.50; steviol, 0.70, dulcoside A, 1.0; steviolbioside, 1.2; stevioside and rebaudioside C, 2.0; rebaudioside D, 3.3; and rebaudioside A, 5.0. The method demonstrated suitable performance for all analytes tested with respect to accuracy (mean recoveries 95-99%), intraday and interday precision for retention times (0.070-0.28% and 0.33-1.0% RSD, respectively), and linearity. The method was used to authenticate steviol glycosides in several samples of Stevia plant material as well as to quantitate steviol glycosides in dietary supplements containing Stevia.

... Yuoh Ku, Olaf Jansen 1 , Carolyn J. Oles, Esther Z. Lazar and Jeanne I. Rader Corresponding Author ... Division of Research & Applied Technology, HFS-840, Center for Food Safety and Applied Nutrition, US Food ... The mobile phase was isocratic with degassed HPLC grade water ...

This article uses folic acid as an example to illustrate some of the complex issues and general principles that emerge when evaluating fortification of the food supply as one possible means to address a public health recommendation. Distributions of current daily folate intakes from conventional foods and dietary supplements were estimated. Intakes that might result from fortification of cereal-grain products and ready-to-eat cereals at various levels for eight age-gender groups were also estimated by using the US Department of Agriculture's 1987-1988 Nationwide Food Consumption Survey. The results illustrate that fortification of the US food supply tends to increase folate intakes of consumers at the high end of the intake distribution curves in the general population to a greater extent than it affects consumers at the low end of the intake distribution curves in the target population. The effectiveness of food fortification options for a target population and the safety for the general population impose conflicting challenges that must be considered concurrently when making decisions about fortifying the US food supply.

Preparations of blue cohosh (Caulophyllum thalictroides) have been used traditionally by Native Americans for medicinal purposes. Dietary supplements containing dried roots or extracts of blue cohosh rhizomes are available as dietary supplements. The safety and efficacy of these preparations have not been systematically evaluated. Recent studies indicate that ingestion of specific alkaloids in blue cohosh preparations can produce birth defects and neonatal heart failure. Blue cohosh also contains saponins, which may be responsible for uterine-stimulating effects. We determined the amounts of major alkaloids and saponins in preparations of blue cohosh by high-performance liquid chromatography (HPLC). Alkaloids and saponins were monitored with a photodiode array detector and an evaporative light-scattering detector, respectively. Profiles were compared with those of authenticated blue cohosh root extracts. Identities of the alkaloids and saponins were confirmed by HPLC/mass spectrometry and nuclear magnetic resonance spectrometry. Calculations based on the results of analyses of dietary supplements showed that maximum daily intake of alkaloids and saponins will vary with the form (e.g., root, liquid extract) and doses recommended in product labeling. Intakes may vary from < 1 to 75 mg/day for alkaloids and from about 9 to 420 mg/day for saponins.

The L-tryptophan eosinophilia myalgia syndrome (L-Trp-EMS), related to ingestion of impure L-Trp, occurred in epidemic proportions in the United States in 1989. Epidemiologic studies implicated 1,1'-ethylidenebis[L-tryptophan] (EBT) as the impurity most highly associated with development of human L-Trp-EMS. We have previously shown that Lewis (LEW/N) rats fed L-Trp implicated in the L-Trp-EMS epidemic (case-associated L-Trp) develop fasciitis and perimyositis which is associated with a reduction in corticotropin-releasing hormone (CRH) mRNA expression in the hypothalamic paraventricular nucleus (PVN). In this study, we report the effects of EBT- and case-associated L-Trp on CRH mRNA expression in the hypothalamic PVN and secretion of adrenocorticotropic hormone (ACTH) and corticosterone (CORT) into the plasma over a time course of 1-6 weeks in the same rats in which we have found fascial thickening and immune cell activation induced by these compounds. Both control L-Trp and EBT stimulated the secretion of ACTH and CORT at 1-2 weeks, whereas case-associated L-Trp did not. EBT and case-associated L-Trp decreased CRH mRNA expression in the PVN at 2-6 weeks, while control L-Trp had no effect. The striking contrast in the effects of case-associated L-Trp and EBT on the HPA axis suggests that the reduction in CRH mRNA levels in the PVN seen in each case may be related to different mechanisms. It is possible that EBT suppresses CRH mRNA expression directly, in the absence of inflammation, while case-associated L-Trp may act through multiple mechanisms, including that associated with inflammation.(ABSTRACT TRUNCATED AT 250 WORDS)

One new cucurbitane-type triterpenoid glycoside, momordicoside U (1), together with five known cucurbitane-type triterpenoids and related glycosides, 3β,7 β,25-trihydroxycucurbita-5,23 (E)-dien-19-al (2), momordicine I (3), momordicine II (4), 3-hydroxycucurbita-5,24-dien-19-al-7,23-di-O-β-glucopyranoside (5), and kuguaglycoside G (6), were isolated from the whole plant of Momordica charantia. Their structures were determined by chemical and spectroscopic methods. Momordicoside U (1) was evaluated for insulin secretion activity in an in vitro insulin secretion assay and displayed moderate activity.

Serum and erythrocyte (RBC) total folate are indicators of folate status. No nationally representative population data exist for folate forms. We measured the serum folate forms (5-methyltetrahydrofolate (5-methylTHF), unmetabolised folic acid (UMFA), non-methyl folate (sum of tetrahydrofolate (THF), 5-formyltetrahydrofolate (5-formylTHF), 5,10-methenyltetrahydrofolate (5,10-methenylTHF)) and MeFox (5-methylTHF oxidation product)) by HPLC-MS/MS and RBC total folate by microbiologic assay in US population ≥ 1 year (n approximately 7500) participating in the National Health and Nutrition Examination Survey 2011-2. Data analysis for serum total folate was conducted including and excluding MeFox. Concentrations (geometric mean; detection rate) of 5-methylTHF (37·5 nmol/l; 100 %), UMFA (1·21 nmol/l; 99·9 %), MeFox (1·53 nmol/l; 98·8 %), and THF (1·01 nmol/l; 85·2 %) were mostly detectable. 5-FormylTHF (3·6 %) and 5,10-methenylTHF (4·4 %) were rarely detected. The biggest contributor to serum total folate was 5-methylTHF (86·7 %); UMFA (4·0 %), non-methyl folate (4·7 %) and MeFox (4·5 %) contributed smaller amounts. Age was positively related to MeFox, but showed a U-shaped pattern for other folates. We generally noted sex and race/ethnic biomarker differences and weak (Spearman's r< 0·4) but significant (P< 0·05) correlations with physiological and lifestyle variables. Fasting, kidney function, smoking and alcohol intake showed negative associations. BMI and body surface area showed positive associations with MeFox but negative associations with other folates. All biomarkers showed significantly higher concentrations with recent folic acid-containing dietary supplement use. These first-time population data for serum folate forms generally show similar associations with demographic, physiological and lifestyle variables as serum total folate. Patterns observed for MeFox may suggest altered folate metabolism dependent on biological characteristics.

ABSTRACT The performance of a novel, transmission-mode, portable, Fourier transform infrared (FTIR) analyzer was evaluated and compared to that of a benchtop attenuated total reflection (ATR)-FTIR spectrometer. The total concentration of trans fatty acids in the fat extracted from 19 representative fast foods was rapidly (FAME). While the FTIR determination is rapid, the time required for extraction and derivatization is not. For all extracts, the total trans FAME concentration varied from approximately 0.5 to 11 % (of total FAME) as determined using the portable FTIR analyzer. The trans fat contents (mean ± SD), expressed in grams per serving and calculated on the basis of total fat content and FTIR determination of trans fat content, were found to be 1.00 ± 0.42 for hamburgers, 0.67 ± 0.78 for chicken tenders, 1.00 ± 1.24 for French fries, and 0.27 ± 0.23 for apple pies. Determinations of total trans-unsaturated FAME were consistent with those obtained by use of ATR-FTIR and GC official methods (AOCS Cd 14e-09 and AOCS Ce 1j-07, respectively). These results indicate that the portable FTIR analyzer is suitable for the rapid and routine quantification of total trans fat measured as FAME prepared from fats extracted from fast foods.

The increased availability and use of botanical dietary supplements and herbal remedies among consumers has been accompanied by an increased frequency of adulteration of these products with synthetic pharmaceuticals. Unscrupulous producers may add drugs and analogues of various classes, such as phosphodiesterase type 5 (PDE-5) inhibitors, weight loss, hypoglycemic, antihypertensive and anti-inflammatory agents, or anabolic steroids, to develop or intensify biological effects of dietary supplements or herbal remedies. The presence of such adulterated products in the marketplace is a worldwide problem and their consumption poses health risks to consumers. Analytical methods that allow rapid and reliable testing of dietary supplements for the presence of synthetic drugs are needed to address such fraudulent practices. Mass spectrometry (MS) and hyphenated techniques such as liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) have become prim...

A method for the determination of total dietary fiber (TDF), as defined by the CODEX Alimentarius, was validated in foods. Based upon the principles of AOAC Official Methods 985.29, 991.43, 2001.03, and 2002.02, the method quantitates high- and low-molecular-weight dietary fiber (HMWDF and LMWDF, respectively). In 2007, McCleary described a method of extended enzymatic digestion at 37 degrees C to simulate human intestinal digestion followed by gravimetric isolation and quantitation of HMWDF and the use of LC to quantitate low-molecular-weight soluble dietary fiber (LMWSDF). The method thus quantitates the complete range of dietary fiber components from resistant starch (by utilizing the digestion conditions of AOAC Method 2002.02) to digestion resistant oligosaccharides (by incorporating the deionization and LC procedures of AOAC Method 2001.03). The method was evaluated through an AOAC collaborative study. Eighteen laboratories participated with 16 laboratories returning valid ass...

Mycotoxins are toxic secondary metabolites produced by certain molds and are common contaminants of many important food crops, such as grains, nuts, and spices. Some mycotoxins are found in fruits, vegetables, and botanical roots. These contaminants have a broad range of toxic effects, including carcinogenicity, immunotoxicity, neurotoxicity, and reproductive and developmental toxicity. The public health concerns related to both acute and chronic effects of mycotoxins in animals have prompted more than 100 countries to establish regulatory limits for some of the well-known mycotoxins, such as the aflatoxins (AFL). Our research focused on method development for 2 of these toxins, AFL and ochratoxin A (OTA), in ginseng and other selected botanical roots. Methods using an immunoaffinity column (IAC) cleanup, liquid chromatographic separation, and fluorescence detection were modified and evaluated. Two types of IAC cleanup were evaluated: IAC for AFL, and IAC for both AFL and OTA. Three...

AOAC Official Method 999.14 is applicable for the determination of choline in milk and infant formulas. To date, its use has not been extended beyond these matrixes. We modified Official Method 999.14 and applied it to the determination of choline in a range of choline-containing dietary supplements. Dietary supplement tablets, capsules, wafers, softgels, liquid products, and drink powders were included. We found that the standard curve could be extended to cover a wider range of choline concentrations and defined a procedure for the use of Norit for samples in which the vitamin C content was high enough to interfere with the analysis. Recoveries of choline added to infant formula powders and to representative dietary supplement tablets, capsules, powdered drink mix, and wafer products were 85-114%. The use of Norit during the procedure did not affect the recovery of choline added to infant formula powders or to dietary supplements. An alkaline digestion was included for use with a ...