Approaches to setting dietary reference values for micronutrients, and translation into recommendations.

Dietary reference values (DRV) are estimates of the daily amounts of nutrients or food energy that meet the needs of healthy people. In the UK, three terms are used to express these estimates, assuming a normal distribution of requirements in a population. These are the estimated average requirement, the lower reference nutrient intake and the reference nutrient intake.

Nutritional and social contribution of meat in diets: Interplays among young urban and rural men.

Considering the recent increase in the demand for meat and its subsequent implications for health and food security, there is an increasing need to explore its nutritional and social importance among young men in settings experiencing nutrition transition. A better understanding of meat in the diets of this group could contribute to the design of socio-culturally appropriate interventions to improve healthy eating, as these men are key decision makers in family food choices. This mixed-methods study aimed to assess the nutritional and social contribution of meat in the diet of young adult men in urban and rural Zambia.

A systematic review of iodine deficiency among women in the UK.

Objective: The present study reviewed the literature on iodine status among women of childbearing age and pregnant women in the UK. Particular attention was given to study quality and methods used to assess iodine status.

Design: A systematic review was conducted to examine the literature and critically evaluate study design.

Oral human papillomavirus infection in England and associated risk factors: a case-control study.

Objectives: This study was conducted to determine the prevalence of and associated risk factors for infection with oral high-risk human papillomavirus (HR-HPV) in adult participants within England, and to explore any association with oral mucosal buccal epithelial cell and whole blood folate concentration.

Design: This was an observational study to determine oral HR-HPV prevalence in the study population. A case-control study was performed to explore the association between infection and folate status.

Methyl-donor depletion of head and neck cancer cells in vitro establishes a less aggressive tumour cell phenotype.

Purpose: DNA methylation plays a fundamental role in the epigenetic control of carcinogenesis and is, in part, influenced by the availability of methyl donors obtained from the diet. In this study, we developed an in-vitro model to investigate whether methyl donor depletion affects the phenotype and gene expression in head and neck squamous cell carcinoma (HNSCC) cells.

Methods: HNSCC cell lines (UD-SCC2 and UPCI-SCC72) were cultured in medium deficient in methionine, folate, and choline or methyl donor complete medium.

Methyl Donor Status Influences DNMT Expression and Global DNA Methylation in Cervical Cancer Cells.

Background: Methyl donor status influences DNA stability and DNA methylation although little is known about effects on DNA methyltransferases. The aim of this study was to determine whether methyldonor status influences DNA methyltransferase (Dnmt) gene expression in cervical cancer cells, and if so, whether there are associated effects on global DNA methylation.

Materials And Methods: The human cervical cancer cell line, C4 II, was grown in complete medium and medium depleted of folate (FM+) and folate and methionine (FM).

Fortified breakfast cereal consumed daily for 12 wk leads to a significant improvement in micronutrient intake and micronutrient status in adolescent girls: a randomised controlled trial.

Background: Poor micronutrient status is reported among adolescents across Europe and USA. This may be related to the well-documented decline in the regular consumption of breakfast by this group. The regular consumption of a breakfast cereal offers a possible means to improve micronutrient status; fortified cereal is likely to have enhanced benefit.

Tumour suppressor gene methylation and cervical cell folate concentration are determinants of high-risk human papillomavirus persistence: a nested case control study.

Background: Persistent infection with one or more high-risk human papillomavirus [HR-HPV] types increases the risk of intraepithelial neoplasia and cervical cancer. A nested case-control study was conducted to investigate the importance of cervical cell folate concentration and tumour suppressor gene methylation as risk factors for HR-HPV persistence.

Methods: Cervical cell samples from 955 women with HR-HPV infection and normal, borderline or mild dyskaryosis were retrieved from the archive of a population-based screening trial.

Multiple vitamin deficiencies in a patient with a history of chronic alcohol excess and self-neglect in the UK.

We report a case of inadequate diet (caused by extreme self-neglect and alcohol excess) which led to chronic severe deficiencies of vitamins A, D and E. At presentation the patient had widespread follicular hyperkeratosis of the skin, keratomalacia of both eyes and a severe cognitive impairment. He responded well to treatment including high dose parenteral vitamins, but lasting impairments in his vision and cognition have caused permanent disability.

Effects of an exercise and hypocaloric healthy eating intervention on indices of psychological health status, hypothalamic-pituitary-adrenal axis regulation and immune function after early-stage breast cancer: a randomised controlled trial.

Introduction: Many women experience emotional distress, depression and anxiety after a diagnosis of breast cancer. Psychological stress and depression have been associated with hypothalamic-pituitary-adrenal (HPA) axis dysregulation that may adversely affect immune system functioning and impact upon survival. This study investigated the effects of a lifestyle intervention on indices of psychological health status, HPA axis regulation and immune function in overweight women recovering from early-stage breast cancer treatment.

Riboflavin depletion of intestinal cells in vitro leads to impaired energy generation and enhanced oxidative stress.

Background: Riboflavin is an essential component of the human diet, with an established role for its derivative cofactors in oxidative metabolism. Our previous in vivo data suggest that riboflavin may act as a signalling molecule in the intestinal lumen, regulating crypt development and cell turnover. Our in vitro studies in riboflavin-depleted intestinal cells in culture indicate that riboflavin depletion impairs normal mitosis.

Effects of mixed dietary supplements on total plasma homocysteine concentrations (tHcy): a randomized, double-blind, placebo-controlled trial.

Background: Although a number of studies have reported raised total plasma homocysteine (tHcy) concentrations in free-living older people, there are no data on homocysteine response to a mixed nutrient supplement in older patients. A raised plasma homocysteine concentration in older patients is partly a reflection of their co-morbidity, including impaired renal function, and there is uncertainty about the extent to which dietary interventions can improve plasma tHcy.

Aim: To determine the plasma tHcy response to dietary supplements during acute illness.

Systemic folate status, rectal mucosal folate concentration and dietary intake in patients at differential risk of bowel cancer (The FAB2 Study).

Background/objectives: Folate has been strongly implicated in the aetiology of colorectal cancer. However, the relationship between dietary folate intake, rectal mucosal folate status and colorectal cancer risk is uncertain. The study aimed to estimate nutrient intakes and measure systemic folate status and rectal mucosal folate concentration in people at differential risk of developing colorectal cancer.

A vitamin B-12 supplement of 500 μg/d for eight weeks does not normalize urinary methylmalonic acid or other biomarkers of vitamin B-12 status in elderly people with moderately poor vitamin B-12 status.

Plasma vitamin B-12 is the most commonly used biomarker of vitamin B-12 status, but the predictive value for low vitamin B-12 status is poor. The urinary methylmalonic acid (uMMA) concentration has potential as a functional biomarker of vitamin B-12 status, but the response to supplemental vitamin B-12 is uncertain. A study was conducted to investigate the responsiveness of uMMA to supplemental vitamin B-12 in comparison with other biomarkers of vitamin B-12 status [plasma vitamin B-12, serum holotranscobalamin (holoTC), plasma MMA] in elderly people with moderately poor vitamin B-12 status.

Improvement in nutritional status reduces the clinical impact of infections in older adults.

Objectives: To determine the effect of a dietary intervention and micronutrient supplementation on self-reported infections in older adults.

Design: A randomized, placebo-controlled intervention trial.

Setting: Community living older people in South Yorkshire, United Kingdom.

Determinants of urinary methylmalonic acid concentration in an elderly population in the United Kingdom.

Background: An age-related deterioration of vitamin B-12 status has been well documented. The early detection of deficiency may prevent the development of serious clinical symptoms, but plasma vitamin B-12 concentration is known to be an imperfect measure of vitamin B-12 status. Urinary methylmalonic acid (MMA) may be a more informative biomarker of vitamin B-12 status; however, biochemical, dietary, and other lifestyle determinants are not known.

Riboflavin in development and cell fate.

Riboflavin (7,8-dimethyl-10-ribitylisoalloxazine; vitamin B2) is a water-soluble vitamin, cofactor derivatives of which (FAD, FMN) act as electron acceptors in the oxidative metabolism of carbohydrate, amino acids and fatty acids and which in the reduced state can donate electrons to complex II of the electron transport chain. This means that riboflavin is essential for energy generation in the aerobic cell, through oxidative phosphorylation. The classic effects of riboflavin deficiency on growth and development have generally been explained in terms of these functions.

Correcting a marginal riboflavin deficiency improves hematologic status in young women in the United Kingdom (RIBOFEM).

Background: Moderate riboflavin deficiency is prevalent in certain population groups in affluent countries, but the functional significance of this deficiency is not clear. Studies have indicated a role for riboflavin in the absorption and use of iron.

Objective: We investigated the effect of riboflavin supplementation on hematologic status in a group of moderately riboflavin-deficient women aged 19-25 y in the United Kingdom.

Riboflavin depletion impairs cell proliferation in adult human duodenum: identification of potential effectors.

Background And Aims: Riboflavin (vitamin B2) is an essential dietary component with a known function in oxidative metabolism. Our previous data using a rat model of riboflavin deficiency suggested that riboflavin also functions as a luminal signaling molecule regulating crypt development and cell turnover. Riboflavin deficiency is prevalent in both high- and low-income countries across the globe.

Recruiting older people to a randomised controlled dietary intervention trial--how hard can it be?

Background: The success of a human intervention trial depends upon the ability to recruit eligible volunteers. Many trials fail because of unrealistic recruitment targets and flawed recruitment strategies. In order to predict recruitment rates accurately, researchers need information on the relative success of various recruitment strategies.

Blood folate status and expression of proteins involved in immune function, inflammation, and coagulation: biochemical and proteomic changes in the plasma of humans in response to long-term synthetic folic acid supplementation.

We used plasma proteomics to identify human proteins responsive to folate status. Plasma was collected from subjects treated with placebo or 1.2 mg of folic acid daily for 12 weeks in a randomized controlled trial.

Comparison of (6 S)-5-methyltetrahydrofolic acid v. folic acid as the reference folate in longer-term human dietary intervention studies assessing the relative bioavailability of natural food folates: comparative changes in folate status following a 16-week placebo-controlled study in healthy adults.

Folic acid (pteroylmonoglutamic acid) has historically been used as the reference folate in human intervention studies assessing the relative bioavailability of dietary folate. Recent studies using labelled folates indicated different plasma response kinetics to folic acid than to natural (food) folates, thus obviously precluding its use in single-dose experiments. Since differences in tissue distribution and site of biotransformation were hypothesised, the question is whether folic acid remains suitable as a reference folate for longer-term intervention studies, where the relative bioavailability of natural (food) folate is assessed based on changes in folate status.

Folate status and aberrant DNA methylation are associated with HPV infection and cervical pathogenesis.

Aberrant DNA methylation is a recognized feature of human cancers, and folate is directly involved in DNA methylation via one-carbon metabolism. Previous reports also suggest that folate status is associated with the natural history of human papillomavirus (HPV) infection. A cross-sectional study was conducted to test the hypothesis that folate status and aberrant DNA methylation show a progressive change across stages of cervical pathology from normal cells to cervical cancer.

Erythrocyte pyridoxamine phosphate oxidase activity: a potential biomarker of riboflavin status?

Background: Riboflavin status is commonly measured by the in vitro stimulation of erythrocyte glutathione reductase with flavin adenine dinucleotide and expressed as an erythrocyte glutathione reductase activation coefficient (EGRAC). However, this assay is insensitive to poor riboflavin status in subjects with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Because G6PD deficiency is common in parts of the world where ariboflavinosis is endemic, it is important to have a measure of riboflavin status that is unaffected by differences in G6PD status.

Study Protocol: randomised controlled trial to investigate the functional significance of marginal riboflavin status in young women in the UK (RIBOFEM).

Background: The functional significance of moderate riboflavin deficiency as it is currently assessed is not well understood. Animal and human studies have suggested a role for riboflavin in the absorption and mobilisation of iron and as such may be important in maintaining haematological status. Recent National Diet and Nutrition Surveys in the United Kingdom have shown that young women in particular are at risk of moderate riboflavin deficiency and low iron status.