The efficacy and safety of nutritional supplement use in a representative sample of adults in the North/South Ireland Food Consumption Survey

Engineering Redox Cofactor Balance for Improved 5-Methyltetrahydrofolate Production in Escherichia coli

5-Methyltetrahydrofolate (5-MTHF) is the sole active form of folate functioning in the human body and is widely used as a nutraceutical. Unlike the pollution from chemical synthesis, microbial synthesis enables green production of 5-MTHF. In this study, Escherichia coli BL21 (DE3) was selected as the host. Initially, by deleting 6-phosphofructokinase 1 and overexpressing glucose-6-phosphate 1-dehydrogenase and 6-phosphogluconate dehydrogenase, the glycolysis pathway flux decreased, while the pentose phosphate pathway flux enhanced. The ratios of NADH/NAD+ and NADPH/NADP+ increased, indicating elevated NAD(P)H supply. This led to more folate being reduced and the successful accumulation of 5-MTHF to 44.57 μg/L. Subsequently, formate dehydrogenases from Candida boidinii and Candida dubliniensis were expressed, which were capable of catalyzing the reaction of sodium formate oxidation for NAD(P)H regeneration. This further increased the NAD(P)H supply, leading to a rise in 5-MTHF production to 247.36 μg/L. Moreover, to maintain the balance between NADH and NADPH, pntAB and sthA, encoding transhydrogenase, were overexpressed. Finally, by overexpressing six key enzymes in the folate to 5-MTHF pathway and employing fed-batch cultivation in a 3 L fermenter, strain Z13 attained a peak 5-MTHF titer of 3009.03 μg/L, the highest level reported in E. coli so far. This research is a significant step toward industrial-scale microbial 5-MTHF production.

Assessment of the Use of Food Supplements by Military Personnel: Study Protocol and Results

Due to their specific mode of operation, military personnel are challenged physically as well as mentally. In most countries, the use of food supplements by military personnel is not regulated, and a high prevalence of supplementation is expected. However, data on this are scarce or very limited, without insights into the importance of supplementation for the intake of bioactive substances. Our goal was, therefore, to develop a study protocol to enable an assessment of the prevalence of using food supplements and an estimate of the contribution of supplementation practices to the dietary intake of specific nutrients and other compounds. The protocol was tested in a study of Slovene Armed Forces (SAF) personnel. Data were collected using an anonymous questionnaire in a sample of 470 participants from different military units-about half from the barracks located across the country, and the other half returning from military operations abroad. To provide meaningful results, we recorded the use of food supplements and functional foods available in single-sized portions (i.e., energy drinks, protein bars, etc.). Altogether, 68% of the participants reported supplementation, most commonly with vitamin, mineral, and protein supplements. Military rank, participation status in military operations, and physical activity were the main determinants of the specific supplements used. Surprisingly, a lower prevalence of overall and protein supplementation was observed in subjects returning from military operations abroad (62 vs. 74%) than in personnel stationed in barracks across Slovenia; however, the frequency of the use of energy drinks and caffeine supplements was higher in this population (25 vs. 11%). The study design allowed for estimations of the daily intake of supplemented bioactive compounds. We describe the challenges and approaches used in the study to support similar studies in the future and within other populations.

High-Level 5-Methyltetrahydrofolate Bioproduction in Bacillus subtilis by Combining Modular Engineering and Transcriptomics-Guided Global Metabolic Regulation

5-Methyltetrahydrofolate (5-MTHF) is the predominant folate form in human plasma, which has been widely used as a nutraceutical. However, the microbial synthesis of 5-MTHF is currently inefficient, limiting green and sustainable 5-MTHF production. In this study, the Generally Regarded As Safe (GRAS) microorganism Bacillus subtilis was engineered as the 5-MTHF production host. Three precursor supply modules were first optimized by modular engineering for strengthening the supply of guanosine-5-triphosphate (GTP) and p-aminobenzoic acid (pABA). Next, the impact of genome-wide gene expression on 5-MTHF biosynthesis was evaluated using transcriptome analyses, which identified key genes for 5-MTHF production. The effects of potential genes on 5-MTHF synthesis were verified by observing the genes' up-regulated by strong promoter P₅₆₆ and those down-regulated by inhibition through the clustered regularly interspaced short palindromic repeat interference (CRISPRi). Finally, a key gene for improved 5-MTHF biosynthesis, comGC, was integrated into the genome of modular engineered strain B89 for its overexpression and facilitating efficient 5-MTHF synthesis, reaching 3.41 ± 0.10 mg/L with a productivity of 0.21 mg/L/h, which was the highest level achieved by microbial synthesis. The engineered 5-MTHF-producing B. subtilis developed in this work lays the foundation of further enhancing 5-MTHF production by microbial fermentation, which can be used for isolation and purification of 5-MTHF as food and nutraceutical ingredients.

A Nutraceutical Formula Is Effective in Raising the Circulating Vitamin and Mineral Levels in Healthy Subjects: A Randomized Trial

Low levels of nutrient intake are common in industrialized countries. This has negative implications on health and is associated with chronic diseases. Supplementation of vitamins, minerals, and key nutrients to optimal levels may, therefore, be beneficial for individual health and for the health economy. Although the use of supplements has become very common, due to a lack of monitoring, there is very limited data on the efficacy of supplementation with different formulas. In this study, we present the results of a randomized controlled study on the efficacy of a novel formulated nutraceutical, N247, in 250 healthy volunteers aged 26-75 years and a placebo control group (n = 35). The broad-spectrum formulation of N247 includes essential vitamins, minerals, and trace elements that are adequately balanced in regard to synergies and related metabolic functions. Moreover, tolerance, safety, and nutrient availability is an important aspect of daily, long-term use of N247. After 3 months of regular N247 use, levels of vitamins and minerals in serum were significantly increased in the N247 group compared with the control group and a placebo group, with excellent compliance rates. Coupled with additional natural ingredients that aim to increase the potency of the nutrients, N247 may represent a novel and beneficial supplement for individuals with nutritional deficiencies. Clinical Trial Registration:https://clinicaltrials.gov/, identifier: NCT04054505.

Suboptimal Health, Dietary Supplementation, and Public Health Approaches to Regulatory Challenges in Dubai

Objectives: Presently, limited data are available on dietary supplements (DSs) and their associated effects on health status although the consumption of DS continues to expand. This study is aimed to explore the possible relationship between DSs consumption and suboptimal health status (SHS) in Dubai, United Arab Emirates (UAE). Methods: This study was a cross-sectional research held among a sample of citizens and residents in the Emirate of Dubai in the UAE using a well-structured, self-administered, anonymous survey. Frequency tables, odds ratios, and confidence intervals were generated during the data analysis using SPSS version 23. Results: A total of 618 participants were enrolled in this study and fully completed the questionnaire. In this study, 317 participants (51.3%) (95% CI: 47.3%-55.3%) reported the use of DS products. A significant association between DS consumption and suboptimal health status was detected (P < .001). DS consumers had a 1.5-fold increased odds of suboptimal health status when compared with non-DS consumers (95% CI 1.4-1.7). Conclusion: The findings of this study suggest a need to develop policies and programs that will help minimize the risk of possible adverse events that are associated with the utilization of DSs.

Synthetic biology-driven microbial production of folates: Advances and perspectives

With the development and application of synthetic biology, significant progress has been made in the production of folate by microbial fermentation using cell factories, especially for using generally regarded as safe (GRAS) microorganism as production host. In this review, the physiological functions and applications of folates were firstly discussed. Second, the current advances of folate-producing GRAS strains development were summarized. Third, the applications of synthetic biology-based metabolic regulatory tools in GRAS strains were introduced, and the progress in the application of these tools for folate production were summarized. Finally, the challenges to folates efficient production and corresponding emerging strategies to overcome them by synthetic biology were discussed, including the construction of biosensors using tetrahydrofolate riboswitches to regulate metabolic pathways, adaptive evolution to overcome the flux limitations of the folate pathway. The combination of new strategies and tools of synthetic biology is expected to further improve the efficiency of microbial folate synthesis.

Geomapping Vitamin D Status in a Large City and Surrounding Population-Exploring the Impact of Location and Demographics

Vitamin D status was assessed in a large urban area to compare differences in deficiency and to geomap the results. In total, 36,466 participants from 28 geographical areas were identified in this cross-sectional, retrospective analysis of general practitioner (GP)-requested 25(OH)D tests at St James's Hospital, Dublin between 2014 and 2018. The population were community-dwelling adults, median age 50.7 (18-109 years) with 15% of participants deficient (<30 nmol/L), rising to 23% in the winter. Deficiency was greatest in younger (18-39 years) and oldest (80+ years) adults, and in males versus females (18% vs. 11%, p < 0.001). Season was the biggest predictor of deficiency (OR 4.44, winter versus summer, p < 0.001), followed by location (west Dublin OR 2.17, north Dublin 1.54, south Dublin 1.42 versus rest of Ireland, p < 0.001) where several urban areas with an increased prevalence of deficiency were identified. There was no improvement in 25(OH)D over the 5-year period despite increased levels of testing. One in four adults were vitamin D deficient in the winter, with significant variations across locations and demographics. Overall this study identifies key groups at risk of 25(OH)D deficiency and insufficiency, thus providing important public health information for the targeting of interventions to optimise 25(OH)D. Mandatory fortification may be necessary to address this widespread inadequacy.

In vitro and in silico characterisation of Lactobacillus paraplantarum D2-1, a starter culture for soymilk fermentation

Soymilk contains several functional nutrients and is thus a promising ingredient for production of functional foods. The present research aimed to study starter properties, functional characteristics and safety of Lactobacillus paraplantarum D2-1, a promising starter culture for soymilk fermentation. Strain D2-1 actively fermented soymilk within 24 h but had weak activity of additional acid production after 7 d. Succinate and acetoin, which could be linked to flavour and taste, were accumulated in fermented soymilk. In vitro study revealed that the organism has several beneficial properties, including high survival ability in artificial gastric juice, high abilities of mucus adhesion and biofilm formation and production of γ-aminobutyric acid and conjugated linoleic acid, without any significant risks for consumption. Genome sequencing supported the desirable metabolic properties of the strain. These results indicate that L. paraplantarum D2-1 is a suitable starter for soymilk fermentation and is a promising probiotic candidate that can be used safely.

Phylloquinone Intakes and Food Sources and Vitamin K Status in a Nationally Representative Sample of Irish Adults

BACKGROUND

Data from a nationally representative sample of 18- to 64-y-old Irish adults conducted in 1999 highlighted low phylloquinone intakes. That survey, however, did not include older adults (aged ≥65 y), a subgroup that is potentially at higher risk of low phylloquinone intakes, or a biomarker of vitamin K status.

OBJECTIVES

The objectives of this work were to measure the phylloquinone intake and its adequacy and the serum percentage of undercarboxylated osteocalcin (%ucOC), a vitamin K status biomarker, in a nationally representative sample of Irish adults aged 18-90 y, and to compare these newer data on dietary phylloquinone in adults aged 18-64 y with those from the previous survey.

METHODS

Data and biobanked serum samples from the National Adult Nutrition Survey, a randomly selected sample of Irish adults aged 18-90 y (N = 1500), were accessed. Phylloquinone intakes were estimated from 4-d food diary data and were compared across age groups (18-35, 36-50, 51-64, and ≥65 y). Serum %ucOC was assessed by immunoassay (n = 692).

RESULTS

The mean ± SD intake of phylloquinone from all sources was 85.2 ± 59.1 μg/d, 99% of which was derived from food. Phylloquinone intakes and serum %ucOC were significantly (P < 0.05) lower (14-25%) and higher (27-39%), respectively, in the 18- to 35-y age group than in the 36- to 50-y, 51- to 64-y, and ≥65-y age groups (no differences between these 3 groups; P > 0.2 in all cases). Mean phylloquinone intakes had increased (P < 0.01) modestly (6 μg/d) in 18-64-y-olds across a decade. Of the total study population, 55% had phylloquinone intakes below the United Kingdom recommended intake of 1 μg ⋅ kg body weight^-1 ⋅ d^-1 CONCLUSION: Our study shows that younger adults (aged 18-35 y) appear to be at higher risk of inadequate vitamin K intake and lower vitamin K status, the health implications of which are unclear and warrant further investigation.

α-Tocopherol Stereoisomers in Human Plasma Are Affected by the Level and Form of the Vitamin E Supplement Used

BACKGROUND

Studies examining vitamin E intake and the percentage of the population meeting dietary guidelines do not distinguish between natural (RRR-α-tocopherol) and synthetic (all-rac-α-tocopherol) intake, even though these different isomeric forms differ in bioactivity.

OBJECTIVE

This study aimed to determine the effect of RRR-α-tocopherol vs. all-rac-α-tocopherol intake on the percentage of the population meeting the vitamin E recommendation and on plasma α-tocopherol stereoisomer distribution.

METHODS

With the use of data from the Irish National Adult Nutrition Survey (NANS), this study examined the percentage of the Irish population meeting the European Union (EU) RDA for vitamin E of 12 mg/d, correcting for a bioactivity difference in all-rac- vs. RRR-α-tocopherol, where 1 mg of all-rac-α-tocopherol is considered to be equivalent to 1:1.36 (0.74) mg in the EU RDA. In a subcohort of supplement users and nonusers, plasma α- and γ-tocopherol concentrations and α-tocopherol stereoisomer distribution were measured. Receiver operating characteristic (ROC) curve analysis was conducted to determine ability to discriminate supplement user types.

RESULTS

Analysis of the NANS showed that 100% of participants still met the recommended intake of 12 mg/d, after all-rac-α-tocopherol intake was corrected for α-tocopherol equivalent bioactivity. In the subcohort analysis, the percentage of plasma RRR-α-tocopherol was significantly lower in high all-rac-α-tocopherol supplement (>11 mg/d) users (82%) compared with nonusers and with high RRR-α-tocopherol supplement (>35 mg/d) users (91% and 93% respectively, P < 0.01). High RRR-α-tocopherol supplement users had a significantly higher plasma α-tocopherol than low all-rac-α-tocopherol supplement (<2.5 mg/d) users (34 vs. 25 μmol/L, P = 0.01). ROC analysis demonstrated an ability to distinguish between RRR- and all-rac-α-tocopherol consumers, which may be useful in investigating the potential effect of RRR- and all-rac-α-tocopherol intake on health.

CONCLUSIONS

This study demonstrated that the percentage of the population meeting the vitamin E recommendation was unaffected when all-rac-α-tocopherol intake was corrected for α-tocopherol equivalent bioactivity. all-rac-α-Tocopherol intake led to a decrease in the percentage of plasma RRR-α-tocopherol relative to RRR-α-tocopherol intake.

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.

A cross-sectional survey on dietary supplements consumption among Italian teen-agers

Introduction

In the last decades, dietary supplements consumption has increased in the Western world for all age groups. The long-term potentially dangerous effects related to an indiscriminate consumption of dietary supplements are still unknown and are becoming a matter of public health concern. Therefore, the aims of the present study were: to explore the contribution of dietary supplements to micronutrient daily intake, and to evaluate awareness and knowledge about dietary supplements.

Methods

Participants (age ranging from 14 to 18 years) were recruited among students attending 8 high schools in the province of Frosinone (Italy). An anonymous questionnaire, composed of 12 multiple-choice items, was administered to all the participants. T-test and the analysis of variance (ANOVA) were performed to describe differences between means of the groups, while the chi-square test was used to compare observed and expected frequencies. The logistic regression model, aimed at identifying the characteristics of potential consumers of dietary supplements,

Results

A total of 686 teenagers (288 males and 398 females, average age: 17,89±0,91 years) participated in the study. The 83,6% of participants affirmed to be aware of dietary supplements. 239 participants consumed dietary supplements: 118 males and 121 females. 49,1% of females consumed dietary supplements less than twice a week, whereas 43,6% of males consumed dietary supplements from 2 to 5 times per week. Statistically significant differences emerged between the genders with respect to the source of information regarding dietary supplements, the perceived indications for their use, and the choice of the store/place to purchase them.

Discussion

Findings in the present study provide insight into the consumption of dietary supplements among young Italians, highlighting the need to foster further awareness among adolescents about the correct use of dietary supplements, especially in terms of indications and contraindications.

A systematic literature review of complementary and alternative medicine prevalence in EU

BACKGROUND

Studies suggest that complementary and alternative medicine (CAM) is widely used in the European Union (EU). We systematically reviewed data, reporting research quality and the prevalence of CAM use by citizens in Europe; what it is used for, and why.

METHODS

We searched for general population surveys of CAM use by using Ovid MEDLINE (1948 to September 2010), Cochrane Library (1989 to September 2010), CINAHL (1989 to September 2010), EMBASE (1980 to September 2010), PsychINFO including PsychARTICLES (1989 to September 2010), Web of Science (1989 to September 2010), AMED (1985 to September 2010), and CISCOM (1989 to September 2010). Additional studies were identified through experts and grey literature. Cross-sectional, population-based or cohort studies reporting CAM use in any EU language were included. Data were extracted and reviewed by 2 authors using a pre-designed extraction protocol with quality assessment instrument.

RESULTS

87 studies were included. Inter-rater reliability was good (kappa = 0.8). Study methodology and quality of reporting were poor. The prevalence of CAM use varied widely within and across EU countries (0.3-86%). Prevalence data demonstrated substantial heterogeneity unrelated to report quality; therefore, we were unable to pool data for meta-analysis; our report is narrative and based on descriptive statistics. Herbal medicine was most commonly reported. CAM users were mainly women. The most common reason for use was dissatisfaction with conventional care; CAM was widely used for musculoskeletal problems.

CONCLUSION

CAM prevalence across the EU is problematic to estimate because studies are generally poor and heterogeneous. A consistent definition of CAM, a core set of CAMs with country-specific variations and a standardised reporting strategy to enhance the accuracy of data pooling would improve reporting quality.

Intakes of dietary folate and other B vitamins are associated with risks of esophageal adenocarcinoma, Barrett's esophagus, and reflux esophagitis

Folate is implicated in carcinogenesis via effects on DNA synthesis, repair, and methylation. Efficient folate metabolism requires other B vitamins and is adversely affected by smoking and alcohol. Esophageal adenocarcinoma (EAC) may develop through a process involving inflammation [reflux esophagitis (RE)] leading to metaplasia [Barrett's esophagus (BE)] and carcinoma. Within a population-based, case-control study, we investigated associations between dietary folate and related factors and risks of EAC, BE, and RE. EAC and BE cases had histologically confirmed disease; RE cases had endoscopically visible inflammation. Controls, age-sex frequency matched to EAC cases, were selected through population and general practice registers. Participants underwent structured interviews and completed food-frequency questionnaires. Multivariate ORs and 95% CIs were computed using logistic regression. A total of 256 controls and 223 EAC, 220 BE, and 219 RE cases participated. EAC risk decreased with increasing folate intake (OR highest vs. lowest = 0.56; 95% CI: 0.31, 1.00; P-trend < 0.01). Similar trends were found for BE (P-trend < 0.01) and RE (P-trend = 0.01). Vitamin B-6 intake was significantly inversely related to risks of all 3 lesions. Riboflavin intake was inversely associated with RE. Vitamin B-12 intake was positively associated with EAC. For EAC, there was a borderline significant interaction between folate intake and smoking (P-interaction = 0.053); compared with nonsmokers with high (≥ median) folate intake, current smokers with low intakes (<median) had an 8-fold increased risk (OR: 8.15; 95% CI: 3.61, 18.40). The same group had increased BE risk (OR: 2.93; 95% CI: 1.24, 6.92; P-interaction = 0.12). Folate and other dietary methyl-group factors are implicated in the etiology of EAC and its precursors.

Characterisation and toxicological assessment of Neutral Methacrylate Copolymer for GRAS evaluation

Neutral Methacrylate Copolymer is a fully polymerised copolymer used in the pharmaceutical industry to permit pH-independent delayed release of active ingredients from oral dosage forms. This function has potential use with food supplements and this article describes available information on the safety of the substance. Oral administration of radiolabelled copolymer to rats resulted in the detection of chemically unchanged copolymer in the faeces, with negligible absorption. Safety studies revealed no adverse toxicity following repeated administration at doses of up to 2000 mg/kg bw/d in a sub-chronic study in rats or 250 mg/kg bw/d in a sub-chronic study in dogs. No reproductive toxicity occurred at up to 2000 mg/kg bw/d in rats or rabbits. The substance shows no evidence of genotoxicity, has low acute toxicity and no irritation or sensitisation potential. An ADI value of 20 mg/kg bw was concluded from two alternative approaches. Daily exposure from use in dietary supplements is estimated as up to 10.0 mg/kg bw in adults and 13.3 mg/kg bw in children. There would therefore appear to be no safety concerns under the intended conditions of use. The information provided is intended to support an evaluation that the substance may be "generally recognized as safe" (GRAS).

Use of food supplements and determinants of usage in a sample Italian adult population

OBJECTIVE

The aims were to collect data on consumption of different food supplements in a sample of the adult Italian population and to characterize users by demographic, physical and health-related characteristics, lifestyle and behaviour.

DESIGN

Cross-sectional survey.

SETTING

The study was conducted in 2008 in ten towns of Italy (two towns from each of the five macro-areas: Northwest, Northeast, Centre, South and Islands).

SUBJECTS

Adults (n 10 000) aged ≥18 years were randomly selected and asked to fill in a self-administered questionnaire regarding their use of food supplements and the above variables. The effect of these variables on food supplement use was evaluated by univariate and multivariate logistic regression.

RESULTS

Of the 1723 individuals who returned the questionnaire, 49% were users of food supplements. A large proportion (54%) of users used more than one category of food supplement: vitamin and/or mineral supplements were the most used (61%), followed by supplements with botanicals and botanical extracts (28%). The results obtained by logistic regression showed that gender, town size, education level, sports practice, regular use of wholemeal cereal-based foods and presence of a low stress level were determinants for the use of food supplements in the examined population. However, these determinants were not shared by all categories of supplements.

CONCLUSIONS

The results of this preliminary study highlight that associations between demographic, dietary and lifestyle factors and use of different categories of food supplements differ according to products, and cannot be accounted for simply by dichotomizing individuals as users or non-users.

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.

The role of vitamers and dietary-based metabolites of vitamin D in prevention of vitamin D deficiency

There is little doubt that vitamin D deficiency across all age groups in Europe is a problem. Low vitamin D status arises due to limited, if any, dermal synthesis during the winter months at latitudes above 40°N, putting increased importance on dietary supply of the vitamin. However, dietary intakes by most populations are low due to the limited supply of vitamin D-rich foods in the food chain. Thus strategies that effectively address this public health issue are urgently required. It has been emphasized and re-emphasized that there are only a limited number of public health strategies available to correct low dietary vitamin D intake: (1) improving intake of naturally occurring vitamin D-rich foods, (2) vitamin D fortification (mandatory or voluntarily) of food, and (3) vitamin D supplementation. Recent evidence suggests that the levels of vitamin D added to food would need to be high so as to ensure dietary requirements are met and health outcomes optimized. In addition, knowledge of the most effective forms of vitamin D to use in some of these preventative approaches is important. There is still uncertainty in relation to the relative efficacy of vitamin D₂ versus D₃, the two main food derived forms and those used in vitamin D supplements. The major metabolite of vitamin D with biological activity is 1,25(OH)₂D; however, this is usually used for pharmacological purposes and is not typically used in normal, healthy people. The other major metabolite, 25(OH)D, which has also been used for pharmacological purposes is present in certain foods such as meat and meat products (particularly offal) as well as eggs. This metabolite may have the potential to boost vitamin D status up to five times more effectively that native vitamin D₃ in foods. However, the exact bioactivity of this compound needs to be established.

The third Italian National Food Consumption Survey, INRAN-SCAI 2005-06--part 1: nutrient intakes in Italy

BACKGROUND AND AIMS

Italian National Food Consumption Survey, INRAN-SCAI 2005-06, is the third national food consumption survey performed in Italy. This study describes energy and nutrient intakes in Italy.

METHODS AND RESULTS

A national cross-sectional food consumption survey was conducted using consecutive 3-day food records between October 2005 and December 2006. A sample of 3323 males and females aged 0.1-97.7 years living in private households was investigated. Individual food records were converted into energy and nutrient intakes with the use of recently updated national food composition databases. For each subject, intakes of energy and of 27 nutrients were calculated, including six minerals (i.e., iron, calcium, phosphorus, magnesium, potassium and zinc) and 10 vitamins (i.e., thiamine, riboflavin, vitamin C, vitamin B₆, retinol, β-carotene, vitamin A as retinol equivalents (REs), vitamin E, vitamin D and vitamin B₁₂. On average, 36% of calories appeared to derive from fat (11% from saturated fatty acids) and 45% from available carbohydrates (15% from soluble carbohydrates).

CONCLUSIONS

The results of the INRAN-SCAI 2005-06 survey in terms of nutrient intakes provide an important piece of information for nutrition surveillance of the population and may also be used to identify priorities for further research.

Legislation on nutraceuticals and food supplements: a comparison between regulations in U.S.A. and E.U

This chapter provides a short review of the main regulations concerning functional food and nutraceutical products set out by the U.S. Food and Drug Administration and in the European Union by the European Commission. The directives are presented in chronological order with an overview on the reaction and feedback they received from consumers and manufacturing industry. A comparison between the U.S. and E.U. regulations, their acceptance and impact on the market is presented, together with a final suggestion to enhance the future development and distribution of functional products, which belong to an equivocal area between food and drugs.

The nutrition transition in the Republic of Ireland: trends in energy and nutrient supply from 1961 to 2007 using Food and Agriculture Organization food balance sheets

Over the course of the last 50 years the Republic of Ireland has gone from being one of the poorest countries in Europe to one of the richest; however, it is now experiencing increasing rates of obesity and non-communicable chronic disease. Although several national nutrition surveys have been carried out in Ireland since 1990, there is little information on the Irish diet before then. We analysed the FAO food balance sheets for Ireland from 1961 to 2007 in order to characterise the changes in energy and nutrient supply that took place during that period. Food balance sheets were downloaded from the FAOSTAT database and per capita supply of commodities was analysed using dietary analysis software. Energy from carbohydrate as a percentage of total energy fell from 55 % in 1961 to 46 % in 2007, whereas energy from fat increased from 29 % to 34 %; these values are well outside WHO recommendations for the prevention of chronic disease. Energy from alcohol as a percentage of total energy has doubled within the last 20 years. On a nutrient-density basis, vitamins and minerals met or exceeded WHO recommendations, apart from vitamin D, folate, Ca and Fe. Although there are methodological limitations associated with the use of food balance sheets, the present results demonstrate that the current imbalances in the Irish diet were already evident several decades ago. Because they are so long established, they will be difficult to reverse unless major public health nutrition interventions are implemented.

Beta-carotene is an important vitamin A source for humans

Experts in the field of carotenoids met at the Hohenheim consensus conference in July 2009 to elucidate the current status of β-carotene research and to summarize the current knowledge with respect to the chemical properties, physiological function, and intake of β-carotene. The experts discussed 17 questions and reached an agreement formulated in a consensus answer in each case. These consensus answers are based on published valid data, which were carefully reviewed by the individual experts and are justified here by background statements. Ascertaining the impact of β-carotene on the total dietary intake of vitamin A is complicated, because the efficiency of conversion of β-carotene to retinol is not a single ratio and different conversion factors have been used in various surveys and following governmental recommendations within different countries. However, a role of β-carotene in fulfilling the recommended intake for vitamin A is apparent from a variety of studies. Thus, besides elucidating the various functions, distribution, and uptake of β-carotene, the consensus conference placed special emphasis on the provitamin A function of β-carotene and the role of β-carotene in the realization of the required/recommended total vitamin A intake in both developed and developing countries. There was consensus that β-carotene is a safe source of vitamin A and that the provitamin A function of β-carotene contributes to vitamin A intake.

How is the adequacy of micronutrient intake assessed across Europe? A systematic literature review

EURopean micronutrient RECommendations Aligned is a network of excellence funded by the European commission, and established to address the problem of differences between countries in micronutrient recommendations as well as to understand how nutritional information including requirements and adequacy of intake is processed among different population groups. The aims of the present paper were to review the methods used for the adequacy assessment of the intake of six micronutrients of public health concern (vitamin A, folate, vitamin B12, Fe, Zn and iodine) in non-European and European nutrition surveys carried out on the apparently healthy population and to compare in particular the adequacy across surveys for folate intake. A systematic literature review was conducted to identify nutrition surveys that assessed micronutrient intake adequacy. The search yielded 9049 records, out of which 337 were eligible for the selected micronutrients. The majority (83·9 %) of the European surveys compared the adequacy of the nutrient intake against the Recommended Dietary Allowances (RDA); only a few surveys (8·0 %) used the estimated average requirement cut-point method, while none of them used the probability approach. The comparison of folate inadequacy across eight countries revealed that about 25 % of the adult female population had inadequate intakes when judged against the different recommendations used by the respective investigators, but nearly 75 % had inadequate intakes when compared against the estimated average requirement cut-point value of 320 μg/d. The present review showed that different methods were applied across Europe to estimate the adequacy of micronutrient intake, which led to different prevalence estimates of micronutrient inadequacy.

One is okay, more is better? Pharmacological aspects and safe limits of nutritional supplements

The use of vitamins, minerals and other supplements has increased considerably during recent years. In the National Diet and Nutrition Survey of British adults aged 19-64 years 40% of those surveyed were taking supplements. In 2005 sales of dietary supplements in the UK were approximately pound sterling 325.7 x 106 in 'bricks and mortar' shops (excluding health food shops). The physiological effects of vitamins and minerals in amounts approximating to the UK reference nutrient intake or the EU RDA are well understood in terms of reducing the risk of micronutrient deficiency. However, the effects of vitamins, minerals and other supplements in larger amounts have attracted much attention in recent decades, and these effects, some of which may be pharmacological, are not as well categorised. Some of these effects are beneficial, some are not. Although vitamins and minerals and other supplements are generally safe at higher doses, there are some safety issues that are relevant in the context of the wide availability of supplements without a doctor's prescription. Thus, several authorities throughout the world have established upper limits (UL) for the intake of vitamins and minerals, and the EU is in the process of setting maximum permitted levels (MPL) for vitamins and minerals in food supplements. The present paper discusses the potential benefits and safety issues relating to the use of supplements at doses higher than the RDA. The rationale for the establishment of UL is also discussed, explaining the differences between the values set by different authorities and the expected guidance and legislation from the European Commission on MPL for vitamins and minerals in food supplements.

The impact of voluntary fortification of foods on micronutrient intakes in Irish adults

The objective of this work was to quantify the impact of the voluntary fortification of foods on dietary intakes of vitamins and minerals of Irish adults. Foods that were voluntarily fortified were identified and pre- and post-fortification levels of micronutrients were determined from data supplied by manufacturers and food composition tables. Using food consumption data in 1379 adults aged 18–64 years, estimated using a 7-d food diary during the North/South Ireland Food Consumption Survey, intakes of micronutrients were determined, both including and excluding the fortification component in foods. Of approximately 3000 foods recorded as consumed, 1·9 % were fortified, mainly breakfast cereals and beverages. Median micronutrient content of fortified foods (FF) ranged from 18–33 % EC RDA per typical serving. Among consumers (65 % of men, 68 % of women), FF contributed, on average, 3·9 % (men) and 5·0 % (women) to mean daily intake (MDI) of energy. Relative to their contribution to MDI of energy, FF contribute a greater % MDI for Fe (men 16, women 19), folate (men 18, women 21), vitamins B1(men 14, women 16), B2(men 16, women 18), B6(men 12, women 15), D (men 5, women 11), B12(men 5, women 7) and niacin (men 10, women 12). Fortification significantly improved the adequacy of intake of some micronutrients, particularly of riboflavin, folate, vitamin D and Fe in women and did not contribute to an increased risk of adverse effects from excessive intake of any micronutrient.

Vitamin D status of 51–75-year-old Irish women: its determinants and impact on biochemical indices of bone turnover

Objectives

To assess the vitamin D status of Irish postmenopausal women during wintertime, and to examine its relationship with serum parathyroid hormone (PTH) and biochemical markers of bone turnover. In addition, the determinants of wintertime serum 25-hydroxyvitamin D (25OH–D) levels in these women were investigated.

Design

A cross-sectional observational study.

Setting

Cork City, Ireland (52°N).

Subjects

Ninety-five apparently healthy, free-living postmenopausal women (aged 51–75 years), not taking any medication and free from any condition likely to affect vitamin D status or calcium/bone metabolism.

Results

Forty-eight per cent and 7% of women had serum 25OH–D levels <50 nmol l−1and <25 nmol l−1, respectively. 25OH–D levels in these women were positively associated with dietary calcium intake (P= 0.0002) and use of vitamin D-containing supplements (P= 0.031), and negatively associated with cigarette smoking (P= 0.027) and body mass index (BMI) (P= 0.030). Low serum 25OH-D levels (<50 nmol l−1) were associated (P<0.01) with elevated serum PTH levels. There were no significant differences in urinary pyridinium crosslinks or serum osteocalcin, biochemical indices of bone turnover, between subjects with serum 25OH–D levels above or below 50 nmol l−1.

Conclusions

A high proportion of Irish postmenopausal women had low vitamin D status (< 50 nmol l−1) during late wintertime, which appeared to lead to elevated levels of serum PTH but not of bone turnover markers. Use of regular low-dose supplemental vitamin D, meeting daily calcium recommendations, cessation of smoking and maintaining BMI in the normal range are important factors that could help maintain adequate vitamin D levels during wintertime in these women.

Dietary and cancer-related behaviors of vitamin/mineral dietary supplement users in a large cohort of French women

BACKGROUND

Several epidemiological studies suggested an association between vitamin/mineral dietary supplement use and cancer risk. However, characteristics of supplement users may themselves be related to cancer risk, and therefore could confound such etiological studies. Very little is known about the characteristics of French supplement users.

AIM OF THE STUDY

To identify cancer-related behaviors and dietary characteristics of vitamin/mineral supplement users in the E3N cohort of French women.

METHODS

Data on supplement use and cancer-related and socio-demographic characteristics were collected by self-administered questionnaires completed by 83,058 women, 67,229 of whom also completed a food frequency questionnaire. Supplement users were compared to non-users by unconditional logistic regression.

RESULTS

Vitamin/mineral supplement users were significantly older and leaner (odds ratio [OR] for BMI >or= 30 vs. <18.5 kg/m2 = 0.35, 95% confidence interval [CI] 0.31-0.39), were less often current smokers, had a higher level of education and had more leisure physical activity. They used more phytooestrogen supplements (OR=3.95, 95 % CI 3.69-4.23), had more often a family history of breast cancer and had more often undergone cancer-screening. Users tended to have a healthier diet: less alcohol, more vegetables, fruit, dairy products, fish and soups. They had higher dietary intakes for most micro-nutrients, fiber and omega3 fatty acids, lower fat intake and either similar or lower prevalence of inadequate dietary intake for all relevant nutrients except magnesium.

CONCLUSIONS

To avoid major confounding, the lifestyle characteristics of supplement users should be considered in studies investigating the association between supplement use and cancer risk.

Vitamin D intake and status in Irish elderly women and adolescent girls

AIM

To assess vitamin D status during summer and winter in Irish girls and elderly women, and to estimate vitamin D intake in these two age-groups.

METHODS

Ambulatory free-living, elderly Irish women (aged 70-76 years; n = 43) and girls (aged 11-13 years; n = 17) were recruited. Fasting serums were collected during August/ September 2002 and February/March 2003 and analysed for 25 (OH) D by HPLC.

RESULTS

Mean daily intakes of vitamin D were 4.6 microg and 2.1 microg in elderly women and girls, respectively. Serum 25 (OH) D was significantly lower (P<0.001) during winter than summer in both age-groups. Eight (20%) and one (during late summer) and sixteen (37.2%) and eight (47%) (during late winter) of the elderly women and girls, respectively, had inadequate vitamin D status (serum 25 (OH) D <40 nmol/l).

CONCLUSION

Inadequate vitamin D status during winter time is quite common in elderly women and adolescent girls in Ireland.

Vitamin intakes from supplements and fortified food in German children and adolescents: results from the DONALD study

Frequent consumption of supplements is a common behavior in adults, as well as children and adolescents. We report on vitamin intake from consuming supplements, taking into account the vitamin intake from fortified and usual foods. A total of 5990 3-d weighed dietary records from 931 German subjects (452 males, 479 females, 2-18 y of age) between 1986 and 2003 from the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study were evaluated. We identified 133 different vitamin-containing supplements in 451 records (7.5%). Slightly more males (8.0%) than females (7.1%) consumed supplements, with highest frequencies found between ages 15 and 18 y. For the majority (10 of 13) of vitamins (vitamin A, vitamin E, vitamin K, thiamin, riboflavin, vitamin B-6, vitamin B-12, niacin, biotin, and vitamin C), intake from usual and fortified food already reached or exceeded 80% of the recommended dietary allowances in all age groups. In the case of folate and pantothenic acid, intake from supplements was necessary to achieve at least 80% of recommended dietary allowances for half of the age groups, especially in females. Supplements with vitamin D considerably helped increase vitamin intake but failed to achieve 80% of references in almost all age groups. Intakes of vitamin A and folic acid exceeded the tolerable upper level most frequently in many age groups and were most pronounced in up to 32% and 13% of children aged 2-3 y. Intake of vitamin D, vitamin E, and vitamin C exceeded the tolerable upper level in single age groups only (<7% of subjects). For the other vitamins, no exceeded limits were identified. The ubiquitous availability of supplements might indicate that even healthy children and adolescents profit by taking them. However, it is difficult to evaluate whether consumers receive more benefits or risks from the unrestricted consumption of supplements as they are marketed today.

Public health aspects of food fortification: a question of balance

Micronutrient malnutrition is widespread throughout the world, with important health and economic consequences. Tools to address this situation include food fortification, supplementation and dietary diversification, each having different and complementary roles. Fortification (mandatory and voluntary) has been practised over several decades in Western countries as well as in developing countries. Iodised salt was introduced in the USA in 1924 to reduce severe I deficiency. In 1938 voluntary enrichment of flours and breads with niacin and Fe was initiated to reduce the incidence of pellagra and Fe-deficiency anaemia respectively. Micronutrient intakes in European countries appear to be generally adequate for most nutrients. However, a number of population subgroups are at higher risk of suboptimal intakes (below the lower reference nutrient intake) for some micronutrients, e.g. folate, Fe, Zn and Ca in children, adolescents and young women. Dietary surveys indicate that fortified foods play a role in mitigating such risks for several important nutrients. The number of foods suited to fortification are considerably limited by several factors, including technological properties (notably moisture, pH and O2 permeability), leading to unacceptable taste and appearance, as well as cost and consumer expectations. In countries in which voluntary fortification is widely practised micronutrient intakes are considerably below tolerable upper intake levels. Concerns about safety are addressed in relation to the potentially increased level or proportion of fortified foods (e.g. following potential EU legislation), for nutrients with relatively low tolerable upper intake levels and where the potential benefit and risks are in different subpopulations (e.g. folic acid). Recent models for assessing these issues are discussed.

Supplement use is associated with health status and health-related behaviors in the 1946 British birth cohort

Use of dietary supplements may be one of a number of health-related behaviors that cluster together. The current study investigated the underlying diet, health-related characteristics, and behaviors of users and nonusers of dietary supplements in a longitudinal study of health. Participants (n = 1776) completed a 5-d food diary including information on dietary supplement use (vitamins, minerals, and nutraceuticals) at age 53 y. Sociodemographic information and data on smoking, alcohol, and physical activity were obtained along with anthropometric measurements, blood pressure, and a blood sample (nonfasting subjects). A significantly greater percentage of women reported supplement use compared with men (45.1 vs. 25.2%). Supplement use was associated with lower BMI, lower waist circumference, higher plasma folate and plasma vitamin B-12 concentrations, nonsmoking, participation in physical activity, and nonmanual social class in women and with plasma folate concentrations and participation in physical activity in men. Nonsupplement users tended to be nonconsumers of breakfast cereals, fruit, fruit juice, yogurt, oily fish, and olive oil and had lower dietary intakes of potassium, magnesium, phosphorus, iron, and vitamin C even after adjustment for sociodemographic and behavioral factors. Overall, supplement users tended to differ from nonsupplement users on a range of health-related behaviors and health status indicators, although there were fewer significant associations in men. Similarly, dietary supplements users tended to have underlying diets that, were healthier and those taking supplements may be the least likely to need them. These results support the notion of a clustering of healthy behaviors and cardiovascular risk factors, particularly for women.

Development and validation of a questionnaire to test knowledge and practices of dietitians regarding dietary supplements

OBJECTIVE

We developed a questionnaire to evaluate dietitians' knowledge and practices about the use of dietary supplements in light of new draft regulations in South Africa that will allow dietitians to prescribe supplements for the management of nutrition-related diseases.

METHODS

A cross-sectional validation study was carried out in two phases: 1) questionnaire planning and development and 2) determination of reliability (internal consistency). The study sample comprised 48 nurses, 105 dietetic interns, and 367 registered dietitians. An expert academic group comprising nine dietitians with research and teaching experience rated the academic relevance and importance of knowledge questions in an item pool of 355 questions to ensure face and content validity. Criterion validity was measured by testing the knowledge questions (KQs) on 48 nurses and 105 dietetic interns. Thereafter questions were deleted based on their difficulty, discrimination, and Cronbach's alpha values. The final questionnaire, which at this point included a test of 50 KQs, was mailed to registered dietitians (n = 1450) in South Africa to determine internal consistency of the final KQs.

RESULTS

Criterion validity of the KQs was indicated by a significant difference (P = 0.000) in the mean test scores between nurses (36.9, 95% confidence interval 24.2 to 39.6) and dietetic interns (40.2, 95% confidence interval 38.8 to 41.7). Item discrimination was attained by the deletion of NQs having a minimum correlation of 0.20 with overall test score. Further, item difficulty was controlled for by removal of questions correctly answered by more than 80% (too easy) or fewer than 20% (too difficult). Internal consistency of the KQs, after completion by 367 dietitians, was 0.87 (Cronbach's alpha). The mean knowledge score of dietitians ranged from 56.5% to 62.5%, with the oldest group (> or =40 y) having the highest score (P = 0.018). Thirty-eight percent of dietitians recommended dietary supplements at least 3 times a week; 51% consumed dietary supplements themselves; and 17% sold them to clients.

CONCLUSIONS

A valid and reliable questionnaire that tests knowledge and practices of dietary supplements was developed for dietitians. This tool can be used by academic institutions to evaluate the knowledge and practices of final-year students. It can also be used on a representative sample of dietitians in South Africa and possibly elsewhere within the profession.

Seasonality of vitamin D status and bone turnover in patients with Crohn's disease

BACKGROUND

While winter-time vitamin D deficiency has been well-documented in Crohn's disease patients, less is known about vitamin D status during summertime and whether a seasonal variation exists in bone turnover.

AIMS

To compare vitamin D status and bone turnover markers in Crohn's disease patients with age- and sex-matched controls during late-summer and late-winter.

SUBJECTS

Crohn's disease patients (n = 44; mean age 36.9 years, currently in remission) and matched controls (n = 44) were recruited from Cork University Hospital and Cork City area, respectively.

METHODS

Bloods were analysed for 25-hydroxyvitamin D, parathyroid hormone, bone-specific alkaline phosphatase, osteocalcin and urine analysed for N-telopeptides of type 1 collagen.

RESULTS

Serum 25-hydroxyvitamin D concentrations were significantly (P < 0.003) lower in Crohn's disease patients than in control subjects during both seasons. In Crohn's disease patients, serum 25-hydroxyvitamin D concentrations were lower (P < 0.0001) whereas serum parathyroid hormone, osteocalcin and bone-specific alkaline phosphatase and urinary N-telopeptides of type 1 collagen levels were higher (P < 0.001) during late-winter than late-summer.

CONCLUSION

There were notable seasonal variations in vitamin D status and bone turnover markers in Crohn's disease patients. The impact of winter decline in vitamin D status and increase in bone turnover on long-term risk of osteopenia/osteoporosis in Crohn's disease patients is unclear.

Vitamin D intake and status in Irish postmenopausal women

OBJECTIVE

The objective of this study was to assess vitamin D status during late-summer and late-winter/early-spring in postmenopausal Irish women, and whether it was influenced by vitamin D-containing supplement use.

DESIGN

A longitudinal observational study.

SETTING

Cork City, Ireland (51 degrees north).

SUBJECTS

A total of 59 apparently healthy, free-living, postmenopausal women aged between 51 and 69 y were sampled during February/March 2002. Of these, 48 and 47 returned during August/September 2002 and February/March 2003, respectively. None of the women were suffering from any medical condition likely to affect vitamin D status. Fasting serums were collected and analysed for 25-hydroxyvitamin D (25 (OH) D) and parathyroid hormone (PTH) by enzyme immunoassays.

RESULTS

Mean daily intake of vitamin D was 3.2 microg from food sources alone and 5.8 microg when vitamin D-containing supplements were included (P<0.01). Serum 25 (OH) D was significantly lower (P<0.001) during February/March 2002 than both August/September 2002 and February/March 2003. Serum 25 (OH) D was also significantly higher (P < or = 0.05) in women who were vitamin D-containing supplement users than nonusers during all three sampling points. Between 17 and 36% of women had inadequate vitamin D status (defined as serum 25 (OH) D <40 nmol/l) during late-winter, but only 4% had inadequate vitamin D status during late-summer. Serum 25 (OH) D was inversely related to serum PTH (r = -0.33; P = 0.028).

CONCLUSION

Suboptimal vitamin D status is common in postmenopausal Irish women during winter. Vitamin D supplementation is associated with improved vitamin D status, even during summertime.

Approaches to assessment of exposure to food- and supplement-derived amino acids

Although the amino acid composition of almost all food proteins is known, estimating the amino acid intake from the diet is extremely difficult because of the lack of available data. A conservative approach would be to determine the population distribution of protein intake, select the 97.5(th) or higher percentile of intake, assume all comes from the target protein, and estimate exposure to some specific amino acid. Any number of dietary survey methodologies could be used to conduct such a conservative approach. However, given the great variety of brands of food supplements, estimates of amino acid intakes from supplements are problematic. Firstly, few studies include supplements in their target nutrient sources because brand-level data would need to be retained and nutritional composition data would need to be recorded. Probabilistic modeling offers some solution provided some basic data are gathered. The percentage of the population regularly taking supplements and the frequency of consumption must be known. Therefore, data on the dietary supplement market would need to be known including the percent of brands containing amino acids and if possible specific amino acids together with concentrations. A probabilistic model as follows would ensue: probability of being a consumer of amino acid supplements; probability distribution function of frequency of use of supplements; probability distribution function of dose per eating occasion; market characteristics; probability distribution function for dietary amino acid intake. Using multiple iterations and perhaps bootstrapping on some elements of the model, fully worst-case model scenarios of exposure could be computed.

Vitamin D intakes in 18–64-y-old Irish adults

OBJECTIVE

To estimate vitamin D intakes in a representative sample of Irish adults and to assess the contribution of foods to these intake estimates.

DESIGN

Vitamin D intakes in 1379, 18-64-y-old adults from the North/South Ireland Food Consumption Survey were estimated using a combination of new analytical data for vitamin D in foods, determined by HPLC, and used to revise recipe calculations, together with existing data from McCance and Widdowson's The Composition of Foods, 5th Edition plus supplements.

RESULTS

The total mean daily intake (MDI) of vitamin D (1 microg=40 IU) from all sources was 4.2 microg. The MDI was significantly higher (P<0.001) when the contribution from nutritional supplements was included (4.2 microg) compared with food sources only (3.2 microg). Men had significantly higher intakes (4.4 microg) than women (4.0 microg; P<0.001), which increased significantly (P<0.001) with age in both sexes. Meat/meat products (30.1%), fish/fish products (14.3%) and eggs/egg dishes (9.1%) were the main contributors to vitamin D intake. Supplements contributed 6.8 and 12% to MDI in men and women, respectively. In all, 74% of adults had an MDI of vitamin D that was less than the median (5 microg) of the recommended daily range of 0-10 microg.

CONCLUSION

The findings of this study suggest that a large number of Irish adults have low vitamin D intakes. This, along with emerging evidence of low vitamin D status in at least some population subgroups, suggests that strategies to increase vitamin D intakes, including fortification of food, should be investigated.

Evolution of dietary antioxidants

Oxygen is vital for most organisms but, paradoxically, damages key biological sites. Oxygenic threat is met by antioxidants that evolved in parallel with our oxygenic atmosphere. Plants employ antioxidants to defend their structures against reactive oxygen species (ROS; oxidants) produced during photosynthesis. The human body is exposed to these same oxidants, and we have also evolved an effective antioxidant system. However, this is not infallible. ROS breach defences, oxidative damage ensues, accumulates with age, and causes a variety of pathological changes. Plant-based, antioxidant-rich foods traditionally formed the major part of the human diet, and plant-based dietary antioxidants are hypothesized to have an important role in maintaining human health. This hypothesis is logical in evolutionary terms, especially when we consider the relatively hypoxic environment in which humans may have evolved. In this paper, the human diet is discussed briefly in terms of its evolutionary development, different strategies of antioxidant defence are outlined, and evolution of dietary antioxidants is discussed from the perspectives of plant need and our current dietary requirements. Finally, possibilities in regard to dietary antioxidants, evolution, and human health are presented, and an evolutionary cost-benefit analysis is presented in relation to why we lost the ability to make ascorbic acid (vitamin C) although we retained an absolute requirement for it.

Effects of cultivation conditions on folate production by lactic acid bacteria

A variety of lactic acid bacteria were screened for their ability to produce folate intracellularly and/or extracellularly. Lactococcus lactis, Streptococcus thermophilus, and Leuconostoc spp. all produced folate, while most Lactobacillus spp., with the exception of Lactobacillus plantarum, were not able to produce folate. Folate production was further investigated in L. lactis as a model organism for metabolic engineering and in S. thermophilus for direct translation to (dairy) applications. For both these two lactic acid bacteria, an inverse relationship was observed between growth rate and folate production. When cultures were grown at inhibitory concentrations of antibiotics or salt or when the bacteria were subjected to low growth rates in chemostat cultures, folate levels in the cultures were increased relative to cell mass and (lactic) acid production. S. thermophilus excreted more folate than L. lactis, presumably as a result of differences in the number of glutamyl residues of the folate produced. In S. thermophilus 5,10-methenyl and 5-formyl tetrahydrofolate were detected as the major folate derivatives, both containing three glutamyl residues, while in L. lactis 5,10-methenyl and 10-formyl tetrahydrofolate were found, both with either four, five, or six glutamyl residues. Excretion of folate was stimulated at lower pH in S. thermophilus, but pH had no effect on folate excretion by L. lactis. Finally, several environmental parameters that influence folate production in these lactic acid bacteria were observed; high external pH increased folate production and the addition of p-aminobenzoic acid stimulated folate production, while high tyrosine concentrations led to decreased folate biosynthesis.

Increased production of folate by metabolic engineering of Lactococcus lactis

The dairy starter bacterium Lactococcus lactis is able to synthesize folate and accumulates large amounts of folate, predominantly in the polyglutamyl form. Only small amounts of the produced folate are released in the extracellular medium. Five genes involved in folate biosynthesis were identified in a folate gene cluster in L. lactis MG1363: folA, folB, folKE, folP, and folC. The gene folKE encodes the biprotein 2-amino-4-hydroxy-6-hydroxymethyldihydropteridine pyrophosphokinase and GTP cyclohydrolase I. The overexpression of folKE in L. lactis was found to increase the extracellular folate production almost 10-fold, while the total folate production increased almost 3-fold. The controlled combined overexpression of folKE and folC, encoding polyglutamyl folate synthetase, increased the retention of folate in the cell. The cloning and overexpression of folA, encoding dihydrofolate reductase, decreased the folate production twofold, suggesting a feedback inhibition of reduced folates on folate biosynthesis.

Impact of ready-to-eat breakfast cereal (RTEBC) consumption on adequacy of micronutrient intakes and compliance with dietary recommendations in Irish adults

OBJECTIVE

To describe the consumption of ready-to-eat-breakfast cereals (RTEBCs) in Irish adults and its impact on adequacy and safety of micronutrient intakes and compliance with dietary recommendations.

DESIGN

Analysis for this paper used data from the North/South Ireland Food Consumption Survey that estimated habitual food intake using a 7-day food diary in a representative sample of adults aged 18-64 years ( 662 men, 717 women).

RESULTS

Despite the small quantity consumed (mean 28.6 g day-1 or 4.7% of total energy intake), RTEBCs made an important contribution to the mean daily intake of carbohydrate (8.1%), starch (10.8%), dietary fibre (9.8%) and non-starch polysaccharides (NSP) (10.8%) in consumers. Increased consumption was associated with a more fibre-dense diet and with greater compliance with dietary recommendations for fat, carbohydrate and NSP. Fortified RTEBCs contributed significantly to mean daily intakes of iron (18%), thiamin (14%), riboflavin (17%), niacin (15%), vitamin B6 (13%), total folate (18%) and vitamin D (10%) and most of the contribution was from micronutrients added to RTEBCs. Increased consumption of fortified RTEBCs was associated with an increased nutrient density for a number of micronutrients and with a lower prevalence of dietary inadequacy of calcium, iron, riboflavin and folate, particularly in women. However, it was not associated with intakes in excess of the Tolerable Upper Intake Level for any micronutrient.

CONCLUSIONS

The consumption of RTEBCs is associated with improved compliance with dietary recommendations for fat, carbohydrate and fibre, with a more micronutrient-dense diet and a reduced risk of dietary inadequacy for calcium, iron, riboflavin and folate, without increasing the risk of excessive intakes of micronutrients.

Can supplements help meet the micronutrient needs of the developing world?

Supplementation has many potential advantages over fortification and dietary approaches for improving micronutrient intake. Pregnant and lactating women and infants are most likely to benefit from supplementation. Recent experience with vitamin A supplementation in young children has proved to be remarkably successful. Demonstrated efficacy of vitamin A supplements for improved child survival in many settings and a technical consensus on how to implement interventions were major factors in achieving this success. Bilateral and UN agencies worked together so that in 1999 80 % of children under 5 years of age in the least-developed countries received a vitamin A capsule in the last 6 months. At least one million child lives saved were associated with the increase in coverage in the last 2 years of the 1990s. Experience with Fe-folate supplements has not been as successful. Whilst a technical consensus has been reached on how to implement programmes to control Fe deficiency, the lack of convincing evidence of efficacy of Fe-folate supplements in terms of maternal and child survival outcomes has undoubtedly contributed to the limited pursuit of effective action. A new multiple micronutrient supplement for use amongst women of reproductive age in developing countries has been formulated. UNICEF is employing the supplement in programmes aimed at helping to prevent low birth weight. The new supplement is likely to be more efficacious than Fe-folate supplements for both maternal and child survival and development outcomes. Successful completion of rigorous efficacy trials will be critical for creating the political support needed to achieve universal coverage.