Janet M. Roseland

Including Food 25-Hydroxyvitamin D in Intake Estimates May Reduce the Discrepancy between Dietary and Serum Measures of Vitamin D Status

The discrepancy between the commonly used vitamin D status measures-intake and serum 25-hydroxyvitamin D [25(OH)D] concentrations--has been perplexing. Sun exposure increases serum 25(OH)D concentrations and is often used as an explanation for the higher population-based serum concentrations in the face of apparently low vitamin D intake. However, sun exposure may not be the total explanation. 25(OH)D, a metabolite of vitamin D, is known to be present in animal-based foods. It has been measured and reported only sporadically and is not currently factored into U.S. estimates of vitamin D intake. Previously unavailable preliminary USDA data specifying the 25(OH)D content of a subset of foods allowed exploration of the potential change in the reported overall vitamin D content of foods when the presence of 25(OH)D was included. The issue of 25(OH)D potency was addressed, and available commodity intake estimates were used to outline trends in projected vitamin D intake when 25(OH)D in foods was taken into account. Given the data available, there were notable increases in the total vitamin D content of a number of animal-based foods when potency-adjusted 25(OH)D was included, and in turn there was a potentially meaningful increase (1.7-2.9 μg or 15-30% of average requirement) in vitamin D intake estimates. The apparent increase could reduce discrepancies between intake estimates and serum 25(OH)D concentrations. The relevance to dietary interventions is discussed, and the need for continued exploration regarding 25(OH)D measurement is highlighted.

Analytical ingredient content and variability of adult multivitamin/mineral products: national estimates for the Dietary Supplement Ingredient Database.

BACKGROUND Multivitamin/mineral products (MVMs) are the dietary supplements most commonly used by US adults. During manufacturing, some ingredients are added in amounts exceeding the label claims to compensate for expected losses during the shelf life. Establishing the health benefits and harms of MVMs requires accurate estimates of nutrient intake from MVMs based on measures of actual rather than labeled ingredient amounts. OBJECTIVES Our goals were to determine relations between analytically measured and labeled ingredient content and to compare adult MVM composition with Recommended Dietary Allowances (RDAs) and Tolerable Upper Intake Levels. DESIGN Adult MVMs were purchased while following a national sampling plan and chemically analyzed for vitamin and mineral content with certified reference materials in qualified laboratories. For each ingredient, predicted mean percentage differences between analytically obtained and labeled amounts were calculated with the use of regression equations. RESULTS For 12 of 18 nutrients, most products had labeled amounts at or above RDAs. The mean measured content of all ingredients (except thiamin) exceeded labeled amounts (overages). Predicted mean percentage differences exceeded labeled amounts by 1.5-13% for copper, manganese, magnesium, niacin, phosphorus, potassium, folic acid, riboflavin, and vitamins B-12, C, and E, and by ∼25% for selenium and iodine, regardless of labeled amount. In contrast, thiamin, vitamin B-6, calcium, iron, and zinc had linear or quadratic relations between the labeled and percentage differences, with ranges from -6.5% to 8.6%, -3.5% to 21%, 7.1% to 29.3%, -0.5% to 16.4%, and -1.9% to 8.1%, respectively. Analytically adjusted ingredient amounts are linked to adult MVMs reported in the NHANES 2003-2008 via the Dietary Supplement Ingredient Database (http://dsid.usda.nih.gov) to facilitate more accurate intake quantification. CONCLUSIONS Vitamin and mineral overages were measured in adult MVMs, most of which already meet RDAs. Therefore, nutrient overexposures from supplements combined with typical food intake may have unintended health consequences, although this would require further examination.

Sodium content of popular commercially processed and restaurant foods in the United States

Purpose The purpose of this study was to provide baseline estimates of sodium levels in 125 popular, sodium-contributing, commercially processed and restaurant foods in the U.S., to assess future changes as manufacturers reformulate foods. Methods In 2010–2013, we obtained ~ 5200 sample units from up to 12 locations and analyzed 1654 composites for sodium and related nutrients (potassium, total dietary fiber, total and saturated fat, and total sugar), as part of the U.S. Department of Agriculture-led sodium-monitoring program. We determined sodium content as mg/100 g, mg/serving, and mg/kcal and compared them against U.S. Food and Drug Administrations (FDA) sodium limits for “low” and “healthy” claims and to the optimal sodium level of < 1.1 mg/kcal, extrapolating from the Healthy Eating Index-2010. Results Results from this study represent the baseline nutrient values to use in assessing future changes as foods are reformulated for sodium reduction. Sodium levels in over half (69 of 125) of the foods, including all main dishes and most Sentinel Foods from fast-food outlets or restaurants (29 of 33 foods), exceeded the FDA sodium limit for using the claim “healthy”. Only 13 of 125 foods had sodium values below 1.1 mg/kcal. We observed a wide range of sodium content among similar food types and brands. Conclusions Current sodium levels in commercially processed and restaurant foods in the U.S. are high and variable. Targeted benchmarks and increased awareness of high sodium content and variability in foods would support reduction of sodium intakes in the U.S.

Interlaboratory Trial for Measurement of Vitamin D and 25-Hydroxyvitamin D [25(OH)D] in Foods and a Dietary Supplement Using Liquid Chromatography-Mass Spectrometry

Assessment of total vitamin D intake from foods and dietary supplements (DSs) may be incomplete if 25-hydroxyvitamin D [25(OH)D] intake is not included. However, 25(OH)D data for such intake assessments are lacking, no food or DS reference materials (RMs) are available, and comparison of laboratory performance has been needed. The primary goal of this study was to evaluate whether vitamin D3 and 25(OH)D3 concentrations in food and DS materials could be measured with acceptable reproducibility. Five experienced laboratories from the United States and other countries participated, all using liquid chromatography tandem-mass spectrometry but no common analytical protocol; however, various methods were used for determining vitamin D3 in the DS. Five animal-based materials (including three commercially available RMs) and one DS were analyzed. Reproducibility results for the materials were acceptable. Thus, it is possible to obtain consistent results among experienced laboratories for vitamin D3 and 25(OH)D3 in foods and a DS.

Vitamin D in Foods: An Evolution of Knowledge

Abstract Accurate data for vitamin D in foods are essential to support epidemiological and clinical studies seeking to identify associations between total vitamin D “exposure” and health outcomes that require quantification of dietary intake and also to inform health professionals about wise food choices for clients. Challenges in developing reliable vitamin D food composition data encompass the existence of multiple forms of the vitamin including its hydroxylated metabolite 25(OH)D, variation among samples of the same food because of animal diet, ultraviolet exposure of provitamin D sterol-containing foods, and validation of analytical methods. Decisions made during development of vitamin D food composition databases also affect the representativeness of mean values used to calculate dietary intake in a specific context. These challenges are discussed, along with the potential impact on estimation of vitamin D intake from foods. Data for naturally occurring vitamin D3 and 25(OH)D3 in animal products are summarized.

The Emerging Issue of 25-Hydroxyvitamin D in Foods

With vitamin D at the center of considerable research and clinical interest, it is concerning that the measurement of its metabolized form, 25-hydroxyvitamin D [(25(OH)D], presents such a conundrum. First, available assays for 25(OH)D do not consistently produce the same measured outcomes, and some have reported quantitative amounts ranging from 17.1 to 35.6 ng/mL for the same sample analyzed depending on the assay used (1). The serum concentration of 25(OH)D is the best measure of vitamin D status, and the variation introduced by the assay differences not only impedes pooling 25(OH)D results and cross-comparing research outcomes, it can also cause differences in clinical determinations and resulting interventions. Fortunately, in 2010, a collaborative effort was established to promote the standardization of laboratorymeasures of serum 25(OH)D (2, 3). Although still a work in progress, these efforts enhance the likelihood that questions about vitamin D benefits and/or adverse effects will be clarified (3). Second, tables of food composition in the United States do not include the 25(OH)D contained in foods.Many animals consumed as human food metabolize some of the vitamin D in their diets to 25(OH)D, which is the major transport form of vitamin D and can be found in many tissues after slaughter (4). Therefore, animalderived foods contain 25(OH)D along with the nonmetabolized form.Moreover, 25(OH)D absorbed from the diet has been found to be more potent in increasing serum concentrations of 25(OH)D than is the equivalent amount of nonmetabolized dietary vitamin D (4). When the 25(OH)D content of animal-derived foods is not measured and included in tables of food composition, the ability to obtain a reasonable estimate of total vitamin D intake, and in turn its impact on vitamin D status, is not only uncertain but very likely to lead to underestimates of true intake. There have been reports concerning the discrepancy between recommended intakes for vitamin D and the reported vitamin D intakes based on national surveys that are coupled to available tables of food composition (5). This has caused public health concern and led to discussions about the need to increase vitamin D fortification of the food supply. However, tables of food composition in the United States currently report quantitative amounts in foods for only the nonmetabolized forms of vitamin D. This may explain, in part, the discrepancy between the reported population-based intakes of vitamin D and the measures of serum 25(OH)D from national surveys, the latter beingmuch higher thanwould be expected given the estimates of intake (6). We, in turn, agree with the conclusion that some, but not all, of the difference between intake and serum measures can be attributed to the contribution of sunlight (7), and the failure to take into account the contributions of 25(OH)D from food is likely a significant factor in this regard. Recently, the USDA and the Office of Dietary Supplements, NIH, worked collaboratively to demonstrate that there could be meaningful underestimates of vitaminD intake in the United States if 25(OH)D in foods is ignored. With the use of the only available US data, which were preliminary and limited, we concluded that current estimates of vitamin D intake among US men and women aged

Nutrient composition and retention in whole turkeys with and without added solution1

20 y would be increased by 1.7–2.9 mg/d [or 15– 30% of the Estimated Average Requirement (6)] if the 25(OH)D in the diet were included in the intake estimates (8). Those who rely on vitamin D intake estimates should be mindful of this data gap. Just as importantly, our work (8) has made it clear that, similar to the challenges facing those measuring 25(OH)D in serum, the determination of 25(OH)D amounts in foods requires exploration and standardization of laboratory methodologies. The USDA has conducted initial studies to examine consistency among analytical laboratories in assaying 25(OH)D in various food materials based on the laboratories’ existing methods (9). Up to now, the lack of well-characterized control and reference materials, as well as the lack of validated methodologies, has presented analytical challenges. However, the results of our exploration suggest the likelihood of agreement among at least some of the existing analytical laboratories and have yielded several potential standard reference materials for measuring 25(OH)D in foods. Such work needs to continue so that vitamin D intake can be more accurately assessed relative to measures of status and better used to simulate or model the impact of modifying the nutrient content of the food supply. Such modeling is an essential task before health policies and related dietary interventions can be determined as appropriate. Targeted efforts and collaborative activities are needed now to allow for systematic analyses of 25(OH)D in foods and to elevate the determination of 25(OH)D in foods to a higher rung within the nutrition research agenda.

A Research Communication Brief: Gluten Analysis in Beef Samples Collected Using a Rigorous, Nationally Representative Sampling Protocol Confirms That Grain-Finished Beef Is Naturally Gluten-Free

&NA; Whole turkeys sold in retail outlets are typically processed with added solutions to improve their taste and tenderness. The purpose of this study was to evaluate the nutrient composition of whole turkeys with and without added solution, and to update the nutrient profile of turkey for the USDA National Nutrient Database for Standard Reference. Eleven pairs of turkeys with added solution were obtained from statistically representative retail outlets using a nationwide sampling plan developed for USDAs National Food and Nutrient Analysis Program; 4 pairs of turkeys without added solution were purchased from local food outlets. Turkeys were roasted to an internal temperature of 165°F (74°C). Values of selected nutrients in light and dark meat, including skin, were determined by USDA approved laboratories using quality assurance protocols. Both raw and cooked turkeys, with and without added solution, were compared by one‐way and 2‐way factorial ANOVA. The results showed a significant interaction for fat (P < 0.0001) and zinc (P = 0.0070) between turkeys that were raw and cooked and those prepared with or without added solution. Fat was higher in raw turkeys with added solution compared to without added solution. Similarly, sodium, phosphorus, and calcium values were significantly higher in turkeys with added solution (P < 0.05) than in turkeys without added solution. Data from this study will be useful for developing strategies to address sodium‐related health issues, nutrition monitoring, consumption surveys, and policy development.

The caffeine contents of dietary supplements commonly purchased in the US: analysis of 53 products with caffeine-containing ingredients

Knowing whether or not a food contains gluten is vital for the growing number of individuals with celiac disease and non-celiac gluten sensitivity. Questions have recently been raised about whether beef from conventionally-raised, grain-finished cattle may contain gluten. To date, basic principles of ruminant digestion have been cited in support of the prevailing expert opinion that beef is inherently gluten-free. For this study, gluten analysis was conducted in beef samples collected using a rigorous nationally representative sampling protocol to determine whether gluten was present. The findings of our research uphold the understanding of the principles of gluten digestion in beef cattle and corroborate recommendations that recognize beef as a naturally gluten-free food.