The aim of the present study was to assess the prevalence of deficiency of folate and vitamin B12 and, simultaneously, the nutrient intake adequacy of folate, vitamin B12, iron, vitamin A, vitamin C, vitamin B6 and calcium in 391 adolescent anaemic (Hb<120 g/l) schoolgirls living in the delta region of Myanmar (Burma). Dietary intakes were assessed using a 3 d estimated food record. The distribution of observed intakes calculated from the food records were adjusted for usual intakes, and the prevalence of inadequacy was estimated using the estimated average requirement cut-point method. Median (first, third quartile) serum folate and vitamin B12 concentrations were 6·5 (4·6, 8·5) nmol/l and 612·8 (443·2, 795·2) pmol/l, respectively. The prevalence of folate deficiency defined as <6·8 nmol/l was 54 %; however, vitamin B12 deficiency defined as <148 pmol/l was negligible (<1 %). The prevalence of inadequate intake of folate was high (100 %) as was the prevalence of inadequate intakes of vitamin A, vitamin C, vitamin B6 and calcium, ranging from 60 to 100 %. Red meat or poultry was rarely consumed, but fish was consumed on a daily basis. Green leafy vegetables were also consumed frequently but consumption of dairy products was uncommon. Folate deficiency was high, and the prevalence of inadequate intake of folate among other key micronutrients was relatively common in this sample of anaemic adolescent schoolgirls. Appropriate strategies such as food fortification and dietary diversification are needed to improve the micronutrient status of these young women to ensure optimal health and future reproductive success.

Folate plays an important role in the synthesis and methylation of DNA as a cofactor in one-carbon metabolism. Inadequate folate intake has been linked to adverse health events. However, comparable information on dietary folate intake across European countries has never been reported. The objective of the present study was to describe the dietary folate intake and its food sources in ten countries in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. A cross-sectional analysis was conducted in 36 034 participants (aged 35–74 years) who completed a single 24 h dietary recall using a computerised interview software program, EPIC-Soft® (International Agency for Research on Cancer, Lyon). Dietary folate intake was estimated using the standardised EPIC Nutrient DataBase, adjusted for age, energy intake, weight and height and weighted by season and day of recall. Adjusted mean dietary folate intake in most centres ranged from 250 to 350 μg/d in men and 200 to 300 μg/d in women. Folate intake tended to be lower among current smokers and heavier alcohol drinkers and to increase with educational level, especially in women. Supplement users (any types) were likely to report higher dietary folate intake in most centres. Vegetables, cereals and fruits, nuts and seeds were the main contributors to folate intake. Nonetheless, the type and pattern of consumption of these main food items varied across the centres. These first comparisons of standardised dietary folate intakes across different European populations show moderate regional differences (except the UK health conscious group), and variation by sex, educational level, smoking and alcohol-drinking status, and supplement use.

Accumulating evidence suggests that changes in dietary folate intake may modulate the risks of Alzheimer's disease (AD) through as yet unknown mechanisms. The aims of the present study were to investigate how dietary folate affects the brain folate distribution, levels of oxidised lipid and DNA damage in the absence/presence of β-amyloid(25–35) (Aβ) peptide challenge, a pathogenic hallmark of AD. Male Wistar rats were assigned to diets with folic acid at 0 (folate deprivation; FD), 8 (moderate folate; MF) and 8 mg folic acid/kg diet+0·003 % in drinking-water (folate supplementation; FS) for 4 weeks. A single injection of Aβ peptide (1 mg/ml) or the vehicle solution was intracerebroventricularly (icv) administrated to rats a week before killing. Brain folate, a marker of oxidative injury, and neuronal death were assayed. In the absence of an Aβ injection, FD rats showed reduced folate levels, and increased 2-thiobarbituric acid-reactive substances and a mitochondrial (mt)DNA 4834 bp large deletion (mtDNA4834 deletion) in the hippocampus compared with the counterpart brains of control rats (P < 0·05). A single icv injection of Aβ peptide potentiated lipid peroxidation in the medulla of FD rats, which was ameliorated by feeding FD rats with the MF and FS diets (P < 0·05). Feeding the FS diet to Aβ-injected rats enriched brain folate levels and reduced mtDNA4834 deletion in the hippocampal and medullary regions compared with corresponding tissues of Aβ+FD rats (P < 0·05). Aβ+FS rats had reduced rates of neuronal death in the frontal cortex compared with Aβ+FD rats (P < 0·05). Taken together, our data revealed that folate deprivation differentially depleted brain folate levels, and increased lipid peroxidation and mtDNA4834 deletions, particularly, in the hippocampus. Upon Aβ challenge, the FS diet may protect various brain regions against lipid peroxidation, mitochondrial genotoxicity and neural death associated with folate deprivation.

Folate intake is strongly influenced by various methods of cooking that can degrade the natural forms of the vitamin in foods. The aim of the present study was to determine the effect of different cooking methods on folate retention in various foods that contribute to folate intake in the UK diet. Typical purchasing and cooking practices of representative food folate sources were determined from a questionnaire survey of local shoppers (n 100). Total folate was determined by microbiological assay (Lactobacillus casei NCIMB 10463) following thermal extraction and tri-enzyme (α-amylase, protease and conjugase) treatment in raw foods and after typical methods of cooking. Boiling for typical time periods resulted in only 49 % retention of folate in spinach (191·8 and 94·4 μg/100 g for raw and boiled spinach respectively; P<0·005), and only 44 % in broccoli (177·1 and 77·0 μg/100 g for raw and boiled broccoli respectively, P<0·0001). Steaming of spinach or broccoli, in contrast, resulted in no significant decrease in folate content, even for the maximum steaming periods of 4·5 min (spinach) and 15·0 min (broccoli). Prolonged grilling of beef for the maximum period of 16·0 min did not result in a significant decrease in folate content (54·3 and 51·5 μg/100 g for raw and grilled beef respectively). Compared with raw values, boiling of whole potatoes (skin and flesh) for 60·0 min did not result in a significant change in folate content (125·1 and 102·8 μg/100 g for raw and boiled potato respectively), nor was there any effect on folate retention whether or not skin was retained during boiling. These current results show that the retention of folate in various foods is highly dependent both on the food in question and the method of cooking. Thus, public health efforts to increase folate intake in order to improve folate status should incorporate practical advice on cooking.