Selenium intakes in the Irish adult population.

Selenium (Se) is an essential trace element which has an important role as a constituent of seleno-proteins involved in various physiological processes. Previous research in Irish adults suggests that intakes of this important nutrient are suboptimal. The aim of the present study was to estimate the current intakes and major food sources of Se by Irish adults. Mean daily intakes (MDIs) of Se were calculated using data from the National Adult Nutrition Survey which involved 1500 Irish adults aged 18-90 years. The Se content of foods and drinks consumed over a 4-d period was determined using data from the Irish Total Diet Study (TDS). Adequacy of Se intakes was assessed by calculating the proportion of the population with intakes below the adequate intake (AI) of 70 µg/d and lower reference nutrient intake of 40 µg/d (LRNI). The MDI of Se in the total population was 71⋅7 µg/d, with significantly higher intakes reported in men (80⋅2 µg/d) compared with women (63⋅4 µg/d, P < 0⋅01). Meat and meat products were the major contributing food group to Se intakes for both men (37 %) and women (31 %). Overall, 47 % of the population were not meeting the recommended AI, while 4 % of the total population were not meeting the LRNI. Although the average intake of Se is above the AI, a significant proportion of the population is not meeting this recommendation and continued monitoring of Se intakes is necessary, particularly by at-risk groups and also in the context of sustainability.

Food and nutrient intakes and compliance with recommendations in school-aged children in Ireland: findings from the National Children's Food Survey II (2017-2018) and changes since 2003-2004.

The childhood years represent a period of increased nutrient requirements during which a balanced diet is important to ensure optimal growth and development. The aim of this study was to examine food and nutrient intakes and compliance with recommendations in school-aged children in Ireland and to examine changes over time. Analyses were based on two National Children's Food Surveys; NCFS (2003-2004) (n 594) and NCFS II (2017-2018) (n 600) which estimated food and nutrient intakes in nationally representative samples of children (5-12 years) using weighed food records (NCFS: 7-d; NCFS II: 4-d). This study found that nutrient intakes among school-aged children in Ireland are generally in compliance with recommendations; however, this population group have higher intakes of saturated fat, free sugars and salt, and lower intakes of dietary fibre than recommended. Furthermore, significant proportions have inadequate intakes of vitamin D, Ca, Fe and folate. Some of the key dietary changes that have occurred since the NCFS (2003-2004) include decreased intakes of sugar-sweetened beverages, fruit juice, milk and potatoes, and increased intakes of wholemeal/brown bread, high-fibre ready-to-eat breakfast cereals, porridge, pasta and whole fruit. Future strategies to address the nutrient gaps identified among this population group could include the continued promotion of healthy food choices (including education around 'healthy' lifestyles and food marketing restrictions), improvements of the food supply through reformulation (fat, sugar, salt, dietary fibre), food fortification for micronutrients of concern (voluntary or mandatory) and/or nutritional supplement recommendations (for nutrients unlikely to be sufficient from food intake alone).

Vitamin B-6 and riboflavin, their metabolic interaction, and relationship with MTHFR genotype in adults aged 18-102 years.

BACKGROUND: The generation of the active form of vitamin B-6, pyridoxal 5'-phosphate (PLP), in tissues is dependent upon riboflavin as flavin mononucleotide, but whether this interaction is important for maintaining vitamin B-6 status is unclear. OBJECTIVE: To investigate vitamin B-6 and riboflavin status, their metabolic interaction, and relationship with methylenetetrahydrofolate reductase (MTHFR) genotype in adulthood. METHODS: Data from 5612 adults aged 18-102 y were drawn from the Irish National Adult Nutrition Survey (NANS; population-based sample) and the Trinity-Ulster Department of Agriculture (TUDA) and Genovit cohorts (volunteer samples). Plasma PLP and erythrocyte glutathione reductase activation coefficient (EGRac), as a functional indicator of riboflavin, were determined. RESULTS: Older (≥65 y) compared with younger (<65 y) adults had significantly lower PLP concentrations (P < 0.001). A stepwise decrease in plasma PLP was observed across riboflavin categories, from optimal (EGRac ≤1.26), to suboptimal (EGRac: 1.27-1.39), to deficient (EGRac ≥1.40) status, an effect most pronounced in older adults (mean ± SEM: 76.4 ± 0.9 vs 65.0 ± 1.1 vs 55.4 ± 1.2 nmol/L; P < 0.001). In individuals with the variant MTHFR 677TT genotype combined with riboflavin deficiency, compared with non-TT (CC/CT) genotype participants with sufficient riboflavin, we observed PLP concentrations of 52.1 ± 2.9 compared with 76.8 ±0.7 nmol/L (P < 0.001). In participants with available dietary data (i.e., NANS cohort, n = 936), PLP was associated with vitamin B-6 intake (nonstandardized regression coefficient ß: 2.49; 95% CI 1.75, 3.24; P < 0.001), supplement use (ß: 81.72; 95% CI: 66.01, 97.43; P < 0.001), fortified food (ß: 12.49; 95% CI: 2.08, 22.91; P = 0.019), and EGRac (ß: -65.81; 95% CI: -99.08, -32.54; P < 0.001), along with BMI (ß: -1.81; 95% CI: -3.31, -0.30; P = 0.019). CONCLUSIONS: These results are consistent with the known metabolic dependency of PLP on flavin mononucleotide (FMN) and suggest that riboflavin may be the limiting nutrient for maintaining vitamin B-6 status, particularly in individuals with the MTHFR 677TT genotype. Randomized trials are necessary to investigate the PLP response to riboflavin intervention within the dietary range. The TUDA study and the NANS are registered at www.ClinicalTrials.gov as NCT02664584 (27 January 2016) and NCT03374748 (15 December 2017), respectively.Clinical Trial Registry details: Trinity-Ulster-Department of Agriculture (TUDA) study, ClinicalTrials.gov no. NCT02664584 (January 27th 2016); National Adult Nutrition Survey (NANS), ClinicalTrials.gov no. NCT03374748 (December 15th 2017).

Adequacy of calcium and vitamin D nutritional status in a nationally representative sample of Irish teenagers aged 13-18 years.

CONTEXT AND PURPOSE: In light of the key roles of vitamin D and calcium in adolescent bone health, there is a critical need for representative data on nutritional status for both micronutrients in teenagers. The present work used data from the recent representative National Teens' Food Survey II (2019-2020) to assess calcium and vitamin D intakes of teenagers in Ireland, including adequacy of such intakes, as well as, for the first time, to characterise serum 25-hydroxyvitamin D (25(OH)D) concentrations and their determinants. METHODS: Usual calcium and vitamin D intake estimates were generated using food intake data (via 4-day weighed food records) from a nationally representative sample of teenagers aged 13-18 years in Ireland (n 428). Serum 25(OH)D was measured (via LC-MS/MS) in the 57.5% (n 246) who provided a blood sample. RESULTS: Sixty-seven and 94% of Irish teenagers had intakes of calcium and vitamin D below the respective Estimated Average Requirements values, reflecting a high degree of inadequacy of intake for both micronutrients (and higher in girls than boys; P < 0.001). In addition, 21.7% and 33.1% of teenagers had serum 25(OH)D < 30 nmol/L (risk of vitamin D deficiency) and 30-49.9 nmol/L (inadequacy), respectively. Extended winter sampling, being aged 16-18 years, low total vitamin D intake, being overweight/obese or being of non-white skin type were significant (P < 0.05) predictors of serum 25(OH)D < 30 nmol/L. CONCLUSIONS: There was a high prevalence of inadequacy of intake of calcium and vitamin D in Irish teenagers, and a fifth were at increased risk of vitamin D deficiency.

Modelling the impact of mandatory folic acid fortification of bread or flour in Ireland on the risk of occurrence of NTD-affected pregnancies in women of childbearing age and on risk of masking vitamin B12 deficiency in older adults.

PURPOSE: The rate of neural tube defects (NTDs) in Europe has remained similar since the 1990s despite folic acid supplement recommendations (400 µg/day) for women of childbearing age. Mandatory folic acid fortification of staple foods has proved effective for reducing the prevalence of NTDs in over 80 countries. This study estimated the impact of addition of folic acid to bread or flour in the Republic of Ireland on reducing the risk of occurrence of NTD-affected pregnancies and the possible risk of masking (undiagnosed) vitamin B12 deficiency in older adults. METHODS: Analyses were based on the Irish National Adult Nutrition Survey (2008-2010). Folic acid fortification was modelled using DaDiet© software. Estimates were made of the increase in average daily folic acid intake in women (18-50 years) and the risk of exceeding the tolerable upper intake level (UL) of 1000 µg for folic acid in adults over 50 years of age. RESULTS: The fortification scenarios examined would reduce the risk of NTD-affected pregnancies by 8-32%, corresponding to an increase of 39-152 µg in the mean daily folic acid intake of WCBA. The risk of masking anaemia associated with vitamin B12 deficiency in older adults would be negligible as the probability of exceeding the UL for folic acid, even by a small amount, is very low (≤ 0.2%). CONCLUSIONS: These levels of addition of folic acid to bread or flour would effectively reduce the risk of NTDs while allowing safe consumption of folic acid at current levels from other fortified foods and supplements.

Nutritional challenges for older adults in Europe: current status and future directions.

Population ageing is rapidly progressing and it is estimated that by 2050 one in every five people globally will be aged 60 years or over. Research has shown that adequate nutritional status can positively impact the ageing process, resulting in improved quality of life and the prevention of chronic disease and mortality. However, due to physiological and social changes associated with ageing, older adults may be at increased risk of nutrient deficiencies. This review aims to investigate the nutrient intake and status of older adults in Europe and to explore the potential role of fortified foods and nutritional supplements in addressing some of the nutritional challenges identified in this population group. The available literature has highlighted unfavourable intakes of total and saturated fat, sugar, salt and dietary fibre together with low intakes and suboptimal status of key micronutrients such as vitamins D, B2, B12, folate and calcium. Evidence has shown that the consumption of fortified foods and use of nutritional supplements make significant contributions to intakes and status of these micronutrients in older adults. Continued monitoring of nutrient intake and status is important in light of changing fortification practices and food consumption patterns. Future strategies to address the nutritional issues identified in older adults could include the promotion of healthy food choices together with improvements of the food supply including reformulation (fat, sugar and salt), food fortification or supplementation to support successful ageing of our populations.

The Development, Validation, and User Evaluation of Foodbook24: A Web-Based Dietary Assessment Tool Developed for the Irish Adult Population.

BACKGROUND: The application of technology in the area of dietary assessment has resulted in the development of an array of tools, which are often specifically designed for a particular country or region. OBJECTIVE: The aim of this study was to describe the development, validation, and user evaluation of a Web-based dietary assessment tool "Foodbook24." METHODS: Foodbook24 is a Web-based, dietary assessment tool consisting of a 24-hour dietary recall (24HDR) and food frequency questionnaire (FFQ) alongside supplementary questionnaires. Validity of the 24HDR component was assessed by 40 participants, who completed 3 nonconsecutive, self-administered 24HDR using Foodbook24 and a 4-day semi-weighed food diary at separate time points. Participants also provided fasted blood samples and 24-hour urine collections for the identification of biomarkers of nutrient and food group intake during each recording period. Statistical analyses on the nutrient and food group intake data derived from each method were performed in SPSS version 20.0 (SPSS Inc). Mean nutrient intakes (and standard deviations) recorded using each method of dietary assessment were calculated. Spearman and Pearson correlations, Wilcoxon Signed Rank and Paired t test were used to investigate the agreement and differences between the nutritional output from Foodbook24 (test method) and the 4-day semi-weighed food diary (reference method). Urinary and plasma biomarkers of nutrient intake were used as an objective validation of Foodbook24. To investigate the user acceptability of Foodbook24, participants from different studies involved with Foodbook24 were asked to complete an evaluation questionnaire. RESULTS: For nutrient intake, correlations between the dietary assessment methods were acceptable to very good in strength and statistically significant (range r=.32 to .75). There were some significant differences between reported mean intakes of micronutrients recorded by both methods; however, with the exception of protein (P=.03), there were no significant differences in the reporting of energy or macronutrient intake. Of the 19 food groups investigated in this analysis, there were significant differences between 6 food groups reported by both methods. Spearman correlations for biomarkers of nutrient and food group intake and reported intake were similar for both methods. A total of 118 participants evaluated the acceptability of Foodbook24. The tool was well-received and the majority, 67.8% (80/118), opted for Foodbook24 as the preferred method for future dietary intake assessment when compared against a traditional interviewer led recall and semi-weighed food diary. CONCLUSIONS: The results of this study demonstrate the validity and user acceptability of Foodbook24. The results also highlight the potential of Foodbook24, a Web-based dietary assessment method, and present a viable alternative to nutritional surveillance in Ireland.

The role of fortified foods and nutritional supplements in increasing vitamin D intake in Irish preschool children.

PURPOSE: There are limited data on the contribution of fortified foods and nutritional supplements to intakes of vitamin D in young children. Our objective was to examine the intake, adequacy, risk of excessive intake and sources of dietary vitamin D. METHODS: The nationally representative cross-sectional dietary survey of young children (aged 1-4 years) (n 500) was used to evaluate vitamin D intake and quantify the contribution of the base diet, fortified foods and nutritional supplements to total intake. RESULTS: Median (IQR) intakes of vitamin D were generally low in this young population, ranging from 2.0 (1.9) to 2.5 (4.9) µg/day. Ninety-three and 78 % of children had intakes below 10 and 5 µg/day, respectively. While vitamin D supplement users (17 %) had the highest intakes [6.7 (6.4) µg/day] (P < 0.001), 74 % had intakes below 10 µg/day. Vitamin D-fortified foods, consumed by 77 % of children [2.2 (2.0) µg/day], made nutritionally significant contributions to intake [0.8 (1.6) µg/day], particularly in younger children [1.5 (4.6) µg/day]. Children who did not use nutritional supplements or fortified foods had significantly (P < 0.001) lower intakes of vitamin D than the other groups [1.0 (0.8) µg/day]. Our analyses show the importance of milk and yoghurt, meat and fortified ready-to-eat cereals as sources of vitamin D in this age group. The use of nutritional supplements or fortified foods at current levels does not represent a risk of intakes exceeding the European Food Safety Authority (EFSA) tolerable upper intake level (UL) (50 µg/day), as intakes did not exceed or even approach the UL (P95: 22 % of UL). CONCLUSION: Intakes of vitamin D in preschool children in Ireland are generally low. Nutritional supplements and fortified foods make significant contributions to intakes of vitamin D, without risk of unacceptably high intakes. Though supplements are effective in raising intakes of vitamin D in users, uptake is low (17 %). Food fortification may represent a suitable public health approach to increasing vitamin D intakes. The national food consumption data of Irish preschool children provide the ideal starting point for modelling of fortification scenarios to identify which foods and levels of addition will ensure effective and safe increases in vitamin D intake.

Estimating safe maximum levels of vitamins and minerals in fortified foods and food supplements.

PURPOSE: To show how safe maximum levels (SML) of vitamins and minerals in fortified foods and supplements may be estimated in population subgroups. METHODS: SML were estimated for adults and 7- to 10-year-old children for six nutrients (retinol, vitamins B6, D and E, folic acid, iron and calcium) using data on usual daily nutrient intakes from Irish national nutrition surveys. RESULTS: SML of nutrients in supplements were lower for children than for adults, except for calcium and iron. Daily energy intake from fortified foods in high consumers (95th percentile) varied by nutrient from 138 to 342 kcal in adults and 40-309 kcal in children. SML (/100 kcal) of nutrients in fortified food were lower for children than adults for vitamins B6 and D, higher for vitamin E, with little difference for other nutrients. Including 25 % 'overage' for nutrients in fortified foods and supplements had little effect on SML. Nutritionally significant amounts of these nutrients can be added safely to supplements and fortified foods for these population subgroups. The estimated SML of nutrients in fortified foods and supplements may be considered safe for these population subgroups over the long term given the food composition and dietary patterns prevailing in the respective dietary surveys. CONCLUSIONS: This risk assessment approach shows how nutrient intake data may be used to estimate, for population subgroups, the SML for vitamins and minerals in both fortified foods and supplements, separately, each taking into account the intake from other dietary sources.

Dietary fat intakes in Irish adults in 2011: how much has changed in 10 years?

Imbalances in dietary fat intakes are linked to several chronic diseases. This study describes dietary intakes and food sources of fat and fatty acids in 1051 Irish adults (aged 18-90 years), using data from the 2011 national food consumption survey, the National Adult Nutrition Survey. It also compares current intakes for 18-64-year-olds with those reported in the last such survey in 2001, the North/South Ireland Food Consumption Survey. Dietary fat intakes were estimated using data from 4-d semi-weighed (2011) and 7-d estimated (2001) food diaries. In 2011, intakes for 18-64-year-olds were as follows: total fat, 34·1 (sd 6·1) % total energy (%TE); SFA, 13·3 (sd 3·3) %TE; MUFA, 12·5 (sd 2·6) %TE; PUFA, 6·1 (sd 2·2) %TE; and trans-fat, 0·511 (sd 0·282) %TE. Apart from MUFA, intakes decreased (P65 years had the highest intakes of SFA; however, intakes were typically higher than UK-recommended values for all groups. In contrast, intakes of long-chain n-3 fatty acids were lowest in younger age groups. Intakes of trans-fat were well within UK-recommended levels. Although there have been some improvements in the profile of intakes since 2001, imbalances persist in the quantity and quality of dietary fat consumed by Irish adults, most notably for total and SFA and for younger age groups for long-chain n-3 fatty acids.

Impact of voluntary fortification and supplement use on dietary intakes and biomarker status of folate and vitamin B-12 in Irish adults.

BACKGROUND: Ireland has traditionally operated a liberal policy of voluntary fortification, but little is known about how this practice, along with supplement use, affects population intakes and status of folate and vitamin B-12. OBJECTIVE: The aim was to examine the relative impact of voluntary fortification and supplement use on dietary intakes and biomarker status of folate and vitamin B-12 in Irish adults. DESIGN: Folic acid and vitamin B-12 from fortified foods and supplements were estimated by using brand information for participants from the cross-sectional National Adult Nutrition Survey 2008-2010. Dietary and biomarker values were compared between 6 mutually exclusive consumption groups formed on the basis of folic acid intake. RESULTS: The consumption of folic acid through fortified foods at low, medium, and high levels of exposure [median (IQR) intakes of 22 (13, 32), 69 (56, 84), and 180 (137, 248) µg/d, respectively]; from supplements [203 (150, 400) µg/d]; or from both sources [287 (220, 438) µg/d] was associated with significantly higher folate intakes and status compared with nonconsumption of folic acid (18% of the population). Median (IQR) red blood cell (RBC) folate increased significantly from 699 (538, 934) nmol/L in nonconsumers to 1040 (83, 1390) nmol/L in consumers with a high intake of fortified foods (P < 0.001), with further nonsignificant increases in supplement users. Supplement use but not fortification was associated with significantly higher serum vitamin B-12 concentrations relative to nonconsumers (P < 0.001). Two-thirds of young women had suboptimal RBC folate for protection against neural tube defects (NTDs); among nonconsumers of folic acid, only 16% attained optimal RBC folate. CONCLUSIONS: The consumption of voluntarily fortified foods and/or supplement use was associated with significantly higher dietary intakes and biomarker status of folate in Irish adults. Of concern, the majority of young women remain suboptimally protected against NTDs.

Small Increments in Vitamin D Intake by Irish Adults over a Decade Show That Strategic Initiatives to Fortify the Food Supply Are Needed.

BACKGROUND: Food fortification could be an effective method of increasing vitamin D intakes and preventing deficiency with minimal risk of excessive dosing. OBJECTIVE: Secular trends in vitamin D intakes were examined over a 10-y period. METHODS: We compared vitamin D intakes among 18- to 64-y-old adults from the base diet, fortified foods, and supplements in 2 nationally representative dietary surveys in 1999 and 2009 implemented using the same methodology. RESULTS: There was a slight increase in the median (IQR) intake of vitamin D from 2.9 (3.2) to 3.5 (3.7) µg/d (mean ± SD, 4.3 ± 4.0 to 5.0 ± 6.4 µg). The median (IQR) intake from the base diet was 2.3 (1.6) µg/d in 1999 and 2.1 (1.8) µg/d in 2009. In vitamin D supplement users, median (IQR) intakes were 7.6 (6.7) and 8.7 (7.2) µg/d and the prevalence of inadequacy decreased from 67% to 57% in 2009. Although the consumption of vitamin D-containing supplements was similar in the 2 surveys (17% and 16%), the use of calcium-vitamin D supplements increased from 3% to 10% among women aged 50-64 y. The prevalence of fortified food consumption was also similar at 60%, and median (IQR) vitamin D intakes in consumers were 2.9 (2.2) and 3.7 (2.9) µg/d in 1999 and 2009, respectively. Mathematical modeling of food fortification using modified vitamin D composition data showed that there is potential to increase vitamin D intakes at the lower end of the distribution, without increasing the risk of exceeding the Tolerable Upper Intake Level. CONCLUSIONS: We report small increases in vitamin D intakes among Irish adults over a decade of focus on vitamin D and in the context of a voluntary fortification policy. Strategic management of vitamin D in the food supply is required to yield measurable benefits.

Impact of voluntary food fortification practices in Ireland: trends in nutrient intakes in Irish adults between 1997-9 and 2008-10.

Because of the discretionary nature of voluntary food fortification in the European Union, there is a need to monitor fortification practices and consumption of fortified foods in order to assess the efficacy and safety of such additions on an ongoing basis. The present study aimed to investigate the nutritional impact of changes in voluntary fortification practices in adults aged 18-64 years using dietary intake data from two nationally representative cross-sectional food consumption surveys, the North/South Ireland Food Consumption Survey (NSIFCS) (1997-9) and the National Adult Nutrition Survey (NANS) (2008-10). The supply of fortified foods increased between 1997-9 and 2008-10, resulting in a higher proportion of adults consuming fortified foods (from 67 to 82 ) and a greater contribution to mean daily energy intake (from 4.6 to 8.4%). The overall nutrient profile of fortified foods consumed remained favourable, i.e. higher in starch and dietary fibre and lower in fat and saturated fat, with polyunsaturated fat, sugars and Na in proportion to energy. Women, particularly those of childbearing age, remained the key beneficiaries of voluntary fortification practices in Ireland. Continued voluntary fortification of foods has increased protection against neural tube defect-affected pregnancy by folic acid and maintained the beneficial impact on the adequacy of Fe intake. Increased consumption of fortified foods did not contribute to an increased risk of intakes exceeding the tolerable upper intake level for any micronutrient. Recent increases in voluntary fortification of foods in Ireland have made a favourable nutritional impact on the diets of adults and have not contributed to an increased risk of adverse effects.

The 3 epimer of 25-hydroxycholecalciferol is present in the circulation of the majority of adults in a nationally representative sample and has endogenous origins.

Fundamental knowledge gaps in relation to the 3 epimer of 25-hydroxycholecalciferol [3-epi-25(OH)D3] limit our understanding of its relevance for vitamin D nutrition and health. The aims of this study were to characterize the 3-epi-25(OH)D3 concentrations in a nationally representative sample of adults and explore its determinants. We also used data from a recent randomized controlled trial (RCT) of supplemental cholecalciferol (vitamin D3) conducted in winter in older adults to directly test the impact of changes in vitamin D status on serum 3-epi-25(OH)D3 concentrations. Serum 25-hydroxycholecalciferol [25(OH)D3] and 3-epi-25(OH)D3 concentrations (via LC-tandem mass spectrometry) from our vitamin D3 RCT in adults (aged ≥50 y) and data on dietary, lifestyle, and biochemical characteristics of participants of the recent National Adult Nutrition Survey in Ireland (aged 18-84 y; n = 1122) were used in the present work. In the subsample of participants who had serum 3-epi-25(OH)D3 concentrations greater than the limit of quantification (n = 1082; 96.4%), the mean, 10th, 50th (median), and 90th percentile concentrations were 2.50, 1.05, 2.18, and 4.30 nmol/L, respectively, whereas the maximum 3-epi-25(OH)D3 concentration was 15.0 nmol/L. A regression model [explaining 29.9% of the variability in serum 3-epi-25(OH)D3] showed that age >50 y, vitamin D supplement use, dietary vitamin D, meat intake, season of blood sampling, and sun exposure habits were significant positive determinants, whereas increasing waist circumference and serum 25-hydroxyergocalciferol concentration were significant negative determinants. The RCT data showed that mean serum 25(OH)D3 and 3-epi-25(OH)D3 concentrations increased (49.3% and 42.1%, respectively) and decreased (-28.0% and -29.1%, respectively) significantly (P < 0.0001) with vitamin D3 (20 µg/d) and placebo supplementation, respectively, over 15 wk of winter. In conclusion, we provide data on serum 3-epi-25(OH)D3 in a nationally representative sample of adults. Our combined observational and RCT data might suggest that both dietary supply and dermal synthesis of vitamin D3 contribute to serum 3-epi-25(OH)D3 concentration.

Dietary vitamin D2--a potentially underestimated contributor to vitamin D nutritional status of adults?

It has been suggested that vitamin D2 is not very prevalent in the human food chain. However, data from a number of recent intervention studies suggest that the majority of subjects had measurable serum 25-hydroxyvitamin D2 (25(OH)D2) concentrations. Serum 25(OH)D2, unlike 25(OH)D3, is not directly influenced by exposure of skin to sun and thus has dietary origins; however, quantifying dietary vitamin D2 is difficult due to the limitations of food composition data. Therefore, the present study aimed to characterise serum 25(OH)D2 concentrations in the participants of the National Adult Nutrition Survey (NANS) in Ireland, and to use these serum concentrations to estimate the intake of vitamin D2 using a mathematical modelling approach. Serum 25(OH)D2 concentration was measured by a liquid chromatography-tandem MS method, and information on diet as well as subject characteristics was obtained from the NANS. Of these participants, 78.7 % (n 884) had serum 25(OH)D2 concentrations above the limit of quantification, and the mean, maximum, 10th, 50th (median) and 90th percentile values of serum 25(OH)D2 concentrations were 3.69, 27.6, 1.71, 2.96 and 6.36 nmol/l, respectively. To approximate the intake of vitamin D2 from these serum 25(OH)D2 concentrations, we used recently published data on the relationship between vitamin D intake and the responses of serum 25(OH)D concentrations. The projected 5th to 95th percentile intakes of vitamin D2 for adults were in the range of 0.9-1.2 and 5-6 µg/d, respectively, and the median intake ranged from 1.7 to 2.3 µg/d. In conclusion, the present data demonstrate that 25(OH)D2 concentrations are present in the sera of adults from this nationally representative sample. Vitamin D2 may have an impact on nutritional adequacy at a population level and thus warrants further investigation.

Adequacy of vitamin D intakes in children and teenagers from the base diet, fortified foods and supplements.

OBJECTIVE: To describe vitamin D intakes in children and teenagers and the contribution from supplements and fortified foods in addition to the base diet. DESIGN: Analysis of 7 d weighed food records collected during the Children's and Teens' National Nutrition Surveys in Ireland. Food composition data for vitamin D were updated from international analytical sources. SETTING: Nationally representative cross-sectional dietary surveys. SUBJECTS: Children (n 594; 5-12 years) and teenagers (n 441; 13-17 years). RESULTS: Median vitamin D intakes were 1.9, 2.1 and 2.4 µg/d in 5-8-, 9-12- and 13-17-year-olds, respectively. The prevalence of vitamin D-containing supplement use was 21, 16 and 15% in 5-8-, 9-12- and 13-17-year-olds and median intakes in users ranged from 6.0 to 6.7 µg/d. The prevalence of inadequate intakes, defined as the percentage with mean daily intakes below the Estimated Average Requirement of 10 µg/d, ranged from 88 to 96% in supplement users. Foods fortified with vitamin D, mainly breakfast cereals, fat spreads and milk, were consumed by 71, 70 and 63 % of 5-8-, 9-12- and 13-17-year-olds. Non-supplement users who consumed vitamin D-fortified foods had median intakes of 1.9-2.5 µg/d, compared with 1.2-1.4 µg/d in those who did not consume fortified foods. CONCLUSIONS: It is currently not possible for children consuming the habitual diet to meet the US Institute of Medicine dietary reference intake for vitamin D. In the absence of nationally representative 25-hydroxyvitamin D data in children, the implications of this observation for prevalence of vitamin D deficiency and health consequences are speculative.

The impact of voluntary food fortification on micronutrient intakes and status in European countries: a review.

This review aims to assess the efficacy and safety of voluntary fortification as an option to address the occurrence of inadequate micronutrient intakes in population subgroups in Europe. Although legislation is harmonised across the European Union, fortification practices and patterns of consumption of fortified foods vary considerably between countries. While the proportion of children consuming fortified foods is greater than adults, the proportion of dietary energy obtained from fortified foods is generally low (<10% in Ireland, where fortified foods are widely consumed). There are a few systematic studies on the overall nutritional impact of voluntary fortification, but there are several studies on the impact of fortified ready-to-eat breakfast cereals. The available evidence indicates that voluntary fortification can reduce the risk of sub-optimal intakes of a range of micronutrients at a population level and can also improve status for selected micronutrients (e.g. folate, vitamin D and riboflavin) in children and adults. Although concerns have been raised regarding the potential of food fortification to lead to unacceptably high micronutrient intakes, particularly for those consuming higher amounts of fortified foods, data from national surveys on total micronutrient intakes (including fortified foods) in Europe show that small proportions of the population, particularly children, may exceed the upper intake level (UL) for some micronutrients. The risk of adverse effects occurring in these individuals exceeding the UL by modest amounts is low. In conclusion, voluntary fortification practices have been shown to improve intake and status of key micronutrients in European Union population groups and do not contribute appreciably to risk of adverse effects.

Vitamin D status of Irish adults: findings from the National Adult Nutrition Survey.

Previous national nutrition surveys in Irish adults did not include blood samples; thus, representative serum 25-hydroxyvitamin D (25(OH)D) data are lacking. In the present study, we characterised serum 25(OH)D concentrations in Irish adults from the recent National Adult Nutrition Survey, and determined the impact of vitamin D supplement use and season on serum 25(OH)D concentrations. Of the total representative sample (n 1500, aged 18+ years), blood samples were available for 1132 adults. Serum 25(OH)D was measured via immunoassay. Vitamin D-containing supplement use was assessed by questionnaire and food diary. Concentrations of serum 25(OH)D were compared by season and in supplement users and non-users. Year-round prevalence rates for serum 25(OH)D concentration < 30, < 40, < 50 and < 75 nmol/l were 6.7, 21.9, 40.1 and 75.6 %, respectively (11.1, 31.1, 55.0 and 84.0 % in winter, respectively). Supplement users had significantly higher serum 25(OH)D concentrations compared to non-users. However, 7.5 % of users had winter serum 25(OH)D < 30 nmol/l. Only 1.3 % had serum 25(OH)D concentrations >125 nmol/l. These first nationally representative serum 25(OH)D data for Irish adults show that while only 6.7 % had serum 25(OH)D < 30 nmol/l (vitamin D deficiency) throughout the year, 40.1 % had levels considered by the Institute of Medicine as being inadequate for bone health. These prevalence estimates were much higher during winter time. While vitamin D supplement use has benefits in terms of vitamin D status, at present rates of usage (17.5 % of Irish adults), it will have only very limited impact at a population level. Food-based strategies, including fortified foods, need to be explored.

Biochemical and metabolomic phenotyping in the identification of a vitamin D responsive metabotype for markers of the metabolic syndrome.

SCOPE: Metabolic phenotyping promises to be a useful tool in human intervention studies. This study examined whether metabolic phenotyping could identify responders to vitamin D supplementation in terms of the metabolic syndrome. METHODS AND RESULTS: In a double-blind, randomised placebo-controlled dietary intervention subjects were assigned to receive 15 µg vitamin D(3) or placebo daily. Serum 25-hydroxyvitamin D (25(OH)D) and biochemical markers of the metabolic syndrome were measured at baseline and following the 4-wk intervention. k-means clustering and (1) H-NMR metabolomic analysis were used to explore responsive phenotypes. Vitamin D supplementation significantly increased serum 25(OH)D to an endpoint concentration of 78.1 ± 20.0 nmol/L (p<0.001). There was no effect of supplementation on the measured markers of the metabolic syndrome. k-means cluster analysis based on 13 biochemical markers of the metabolic syndrome and 25(OH)D concentrations revealed five discrete biomarker clusters. One of these clusters, characterised by lower serum 25(OH)D and higher levels of adipokines, showed significant responses in insulin (15% decrease), homestatic model assessment scores (19% decrease) and c-reactive protein (54% decrease). Metabolomic analysis revealed further changes and the extent of change in serum vitamin D correlated negatively with changes in glucose. CONCLUSION: Overall, metabolic phenotyping revealed a phenotype that was responsive to vitamin D supplementation.

Intake of selected nutrients from foods, from fortification and from supplements in various European countries.

BACKGROUND: Recent European Union regulation requires setting of maximum amount of micronutrients in dietary supplements or foods taking into account the tolerable upper intake level (ULs) established by scientific risk assessment and population reference intakes. OBJECTIVE: To collect and evaluate recently available data on intakes of selected vitamins and minerals from conventional foods, food supplements and fortified foods in adults and children. Intake of calcium, copper, iodine, iron, magnesium, phosphorus, selenium, zinc, folic acid, niacin and total vitamin A/retinol, B(6), D and E was derived from nationally representative surveys in Denmark, Germany, Finland, Ireland, Italy, the Netherlands, Poland, Spain and the United Kingdom. Intake of high consumers, defined as the 95th percentile of each nutrient, was compared to the UL. RESULTS: For most nutrients, adults and children generally consume considerably less than the UL with exceptions being retinol, zinc, iodine, copper and magnesium. The major contributor to intakes for all nutrients and in all countries is from foods in the base diet. The patterns of food supplements and voluntary fortification vary widely among countries with food supplements being responsible for the largest differences in total intakes. In the present study, for those countries with data on fortified foods, fortified foods do not significantly contribute to higher intakes for any nutrient. Total nutrient intake expressed as percentage of the UL is generally higher in children than in adults. CONCLUSION: The risk of excessive intakes is relatively low for the majority of nutrients with a few exceptions. Children are the most vulnerable group as they are more likely to exhibit high intakes relative to the UL. There is a need to develop improved methods for estimating intakes of micronutrients from fortified foods and food supplements in future dietary surveys.