Postdiagnosis dietary factors, supplement use and breast cancer prognosis: Global Cancer Update Programme (CUP Global) systematic literature review and meta-analysis.

Little is known about how diet might influence breast cancer prognosis. The current systematic reviews and meta-analyses summarise the evidence on postdiagnosis dietary factors and breast cancer outcomes from randomised controlled trials and longitudinal observational studies. PubMed and Embase were searched through 31st October 2021. Random-effects linear dose-response meta-analysis was conducted when at least three studies with sufficient information were available. The quality of the evidence was evaluated by an independent Expert Panel. We identified 108 publications. No meta-analysis was conducted for dietary patterns, vegetables, wholegrains, fish, meat, and supplements due to few studies, often with insufficient data. Meta-analysis was only possible for all-cause mortality with dairy, isoflavone, carbohydrate, dietary fibre, alcohol intake and serum 25-hydroxyvitamin D (25(OH)D), and for breast cancer-specific mortality with fruit, dairy, carbohydrate, protein, dietary fat, fibre, alcohol intake and serum 25(OH)D. The results, with few exceptions, were generally null. There was limited-suggestive evidence that predefined dietary patterns may reduce the risk of all-cause and other causes of death; that isoflavone intake reduces the risk of all-cause mortality (relative risk (RR) per 2 mg/day: 0.96, 95% confidence interval (CI): 0.92-1.02), breast cancer-specific mortality (RR for high vs low: 0.83, 95% CI: 0.64-1.07), and recurrence (RR for high vs low: 0.75, 95% CI: 0.61-0.92); that dietary fibre intake decreases all-cause mortality (RR per 10 g/day: 0.87, 95% CI: 0.80-0.94); and that serum 25(OH)D is inversely associated with all-cause and breast cancer-specific mortality (RR per 10 nmol/L: 0.93, 95% CI: 0.89-0.97 and 0.94, 95% CI: 0.90-0.99, respectively). The remaining associations were graded as limited-no conclusion.

Foods, nutrients and hip fracture risk: A prospective study of middle-aged women.

BACKGROUND AND AIMS: Hip fracture affects 1.6 million people globally each year, and increases morbidity and mortality. There is potential for risk reduction through diet modification, but prospective evidence for associations between intake of several foods and nutrients and hip fracture risk is limited. This study aimed to investigate associations between food and nutrient intakes and hip fracture risk in the UK Women's Cohort Study, and to determine the role of body mass index (BMI) as a potential effect modifier. METHODS: Dietary, lifestyle, anthropometric, and socio-economic information of UK women, ages 35-69 years, were collected in a survey at recruitment (1995-1998), and included a validated 217-item food frequency questionnaire. Hip fracture cases were identified by linking participant data at recruitment with their Hospital Episode Statistics (HES) up to March 2019. Cox regression models were used to estimate associations between standard portions of food and nutrient intakes and hip fracture risk over a median follow-up time of 22.3 years. RESULTS: Among 26,318 women linked to HES data (556,331 person-years), 822 hip fracture cases were identified. After adjustment for confounders, every additional cup of tea or coffee per day was associated with a 4% lower risk of hip fracture (HR (95% CI): 0.96 (0.92, 1.00)). A 25 g/day increment of dietary protein intake was also associated with a 14% lower risk of hip fracture (0.86 (0.73, 1.00)). In subgroup analyses, BMI modified linear associations between dietary intakes of protein, calcium, total dairy, milk, and tea and hip fracture risk (pinteraction = 0.02, 0.002, 0.003, 0.001, and 0.003, respectively); these foods and nutrients were associated with a reduced risk of hip fracture in underweight but not healthy or overweight participants. In particular, risk of hip fracture in underweight participants (28 cases, 545 participants) was 45% lower for every 25 g/day protein consumed (0.55 (0.38, 0.78)). CONCLUSIONS: This is the first prospective cohort study internationally of multiple food and nutrient intakes in relation to hip fracture risk by BMI using linkage to hospital records. Results suggest that the potential roles of some foods and nutrients in hip fracture prevention, particularly protein, tea and coffee in underweight women, merit confirmation. PROTOCOL REGISTRATION: Clinicaltrials.gov NCT05081466.

Prenatal and Postpartum Maternal Iodide Intake from Diet and Supplements, Urinary Iodine and Thyroid Hormone Concentrations in a Region of the United Kingdom with Mild-to-Moderate Iodine Deficiency.

Iodine is essential for normal thyroid function, supporting healthy fetal and child development. Iodine requirements increase in pregnancy, but many women in regions without salt iodization have insufficient intakes. We explored associations between iodide intake and urinary iodine concentration (UIC), urinary iodine/creatinine ratio (I/Cr), thyroid stimulating hormone, thyroglobulin, free triiodothyronine, free thyroxine and palpable goiter in a region of mild-to-moderate iodine insufficiency. A total of 246 pregnant women aged 18-40 in Bradford, UK, joined the Health and Iodine in Babies (Hiba) study. They provided detailed information on diet and supplement use, urine and serum samples and were assessed for goiter at around 12, 26 and 36 weeks' gestation, and 6, 18 and 30 weeks postpartum. Dietary iodide intake from food and drink was estimated using six 24 h recalls. During pregnancy, median (IQR) dietary iodide intake was 101 µg/day (54, 142), with 42% from dairy and 9% from white fish. Including supplements, intake was 143 µg/day (94, 196), with 49% < UK reference nutrient intake (140 µg/day). Women with Pakistani heritage had 129 µg/day (87, 190) median total intake. Total intake during pregnancy was associated with 4% (95% CI: 1%, 7%) higher UIC, 5% (3%, 7%) higher I/Cr, 4% (2%, 6%) lower thyroglobulin and 21% (9%, 32%) lower odds of palpable goiter per 50 µg/day. This cohort consumed less iodide in pregnancy than UK and World Health Organization dietary recommendations. UIC, I/Cr and thyroglobulin were associated with intake. Higher intake was associated with fewer goiters. Because dairy was the dominant source of iodide, women following plant-based or low-dairy diets may be at particular risk of iodine insufficiency.

Maternal Fatty Fish Intake Prior to and during Pregnancy and Risks of Adverse Birth Outcomes: Findings from a British Cohort.

Fish is an important source of the essential fatty acids contributing to foetal growth and development, but the evidence linking maternal fatty fish consumption with birth outcomes is inconsistent. In the UK, pregnant women are recommended to consume no more than two 140 g portions of fatty fish per week. This study aimed to investigate the association between fatty fish consumption before and during pregnancy with preterm birth and size at birth in a prospective birth cohort. Dietary intake data were acquired from a cohort of 1208 pregnant women in Leeds, UK (CARE Study) to assess preconception and trimester-specific fatty fish consumption using questionnaires. Multiple 24-h recalls during pregnancy were used to estimate an average fatty fish portion size. Intake was classified as ≤2, >2 portions/week and no fish categories. Following the exclusion of women taking cod liver oil and/or omega-3 supplements, the associations between fatty fish intake with size at birth and preterm delivery (<37 weeks gestation) were examined in multivariable regression models adjusting for confounders including salivary cotinine as a biomarker of smoking status.. The proportion of women reporting any fatty fish intake decreased throughout pregnancy, with the lowest proportion observed in trimester 3 (43%). Mean intakes amongst consumers were considerably lower than that recommended, with the lowest intake amongst consumers observed in the 1st trimester (106 g/week, 95% CI: 99, 113). This was partly due to small portion sizes when consumed, with the mean portion size of fatty fish being 101 g. After adjusting for confounders, no association was observed between fatty fish intake before or during pregnancy with size at birth and preterm delivery.

Soy intake and vasomotor menopausal symptoms among midlife women: a pooled analysis of five studies from the InterLACE consortium.

BACKGROUND/OBJECTIVES: Phytoestrogen rich-foods such as soy may be associated with less frequent/severe vasomotor menopausal symptoms (VMS), although evidence is limited. We thus investigated the associations between the consumption of soy products and soy milk and the frequency/severity of VMS. SUBJECTS/METHODS: We pooled data from 19,351 middle-aged women from five observational studies in Australia, UK, USA, and Japan that contribute to the International Collaboration for a Life course Approach to reproductive health and Chronic disease Events (InterLACE). Information on soy consumption, VMS and covariates were collected by self-report. We included 11,006 women who had complete data on soy consumption, VMS and covariates at baseline for the cross-sectional analysis. For the prospective analysis, 4522 women who were free of VMS at baseline and had complete data on VMS at follow-up were considered. Multinomial logistic regression and binary logistic regression models were used. RESULTS: No statistically significant evidence of an association was found between soy products (relative risk ratio (RRR): 0.92, 95% CI: 0.76-1.11) or soy milk (RRR: 1.24, 95% CI: 0.93-1.65) and the likelihood of reporting frequent or severe VMS cross-sectionally. Prospective results indicated that frequent consumption of soy products (odds ratio (OR): 0.63, 95% CI: 0.45-0.89) but not soy milk (OR: 1.11, 95% CI: 0.85-1.45) was associated with lower likelihood of reporting subsequent VMS, after adjustment for socio-demographic and reproductive factors. CONCLUSIONS: These are the first ever findings from pooled observational data of association between consumption of soy products and VMS.

Dietary intake and blood concentrations of antioxidants and the risk of cardiovascular disease, total cancer, and all-cause mortality: a systematic review and dose-response meta-analysis of prospective studies.

Background: High dietary intake or blood concentrations (as biomarkers of dietary intake) of vitamin C, carotenoids, and vitamin E have been associated with reduced risk of cardiovascular disease, cancer, and mortality, but these associations have not been systematically assessed. Objective: We conducted a systematic review and meta-analysis of prospective studies of dietary intake and blood concentrations of vitamin C, carotenoids, and vitamin E in relation to these outcomes. Design: We searched PubMed and Embase up to 14 February 2018. Summary RRs and 95% CIs were calculated with the use of random-effects models. Results: Sixty-nine prospective studies (99 publications) were included. The summary RR per 100-mg/d increment of dietary vitamin C intake was 0.88 (95% CI: 0.79, 0.98, I2 = 65%, n = 11) for coronary heart disease, 0.92 (95% CI: 0.87, 0.98, I2 = 68%, n = 12) for stroke, 0.89 (95% CI: 0.85, 0.94, I2 = 27%, n = 10) for cardiovascular disease, 0.93 (95% CI: 0.87, 0.99, I2 = 46%, n = 8) for total cancer, and 0.89 (95% CI: 0.85, 0.94, I2 = 80%, n = 14) for all-cause mortality. Corresponding RRs per 50-µmol/L increase in blood concentrations of vitamin C were 0.74 (95% CI: 0.65, 0.83, I2 = 0%, n = 4), 0.70 (95% CI: 0.61, 0.81, I2 = 0%, n = 4), 0.76 (95% CI: 0.65, 0.87, I2 = 56%, n = 6), 0.74 (95% CI: 0.66, 0.82, I2 = 0%, n = 5), and 0.72 (95% CI: 0.66, 0.79, I2 = 0%, n = 8). Dietary intake and/or blood concentrations of carotenoids (total, ß-carotene, α-carotene, ß-cryptoxanthin, lycopene) and α-tocopherol, but not dietary vitamin E, were similarly inversely associated with coronary heart disease, stroke, cardiovascular disease, cancer, and/or all-cause mortality. Conclusions: Higher dietary intake and/or blood concentrations of vitamin C, carotenoids, and α-tocopherol (as markers of fruit and vegetable intake) were associated with reduced risk of cardiovascular disease, total cancer, and all-cause mortality. These results support recommendations to increase fruit and vegetable intake, but not antioxidant supplement use, for chronic disease prevention.

Development of a New Branded UK Food Composition Database for an Online Dietary Assessment Tool.

The current UK food composition tables are limited, containing ~3300 mostly generic food and drink items. To reflect the wide range of food products available to British consumers and to potentially improve accuracy of dietary assessment, a large UK specific electronic food composition database (FCDB) has been developed. A mapping exercise has been conducted that matched micronutrient data from generic food codes to "Back of Pack" data from branded food products using a semi-automated process. After cleaning and processing, version 1.0 of the new FCDB contains 40,274 generic and branded items with associated 120 macronutrient and micronutrient data and 5669 items with portion images. Over 50% of food and drink items were individually mapped to within 10% agreement with the generic food item for energy. Several quality checking procedures were applied after mapping including; identifying foods above and below the expected range for a particular nutrient within that food group and cross-checking the mapping of items such as concentrated and raw/dried products. The new electronic FCDB has substantially increased the size of the current, publically available, UK food tables. The FCDB has been incorporated into myfood24, a new fully automated online dietary assessment tool and, a smartphone application for weight loss.

Calcium intake and colorectal adenoma risk: dose-response meta-analysis of prospective observational studies.

Evidence from randomized controlled trials suggests that calcium may protect against recurrence of colorectal adenomas, which could lead to the subsequent prevention of cancer. Yet the trials used only a large single dose and were of small sizes, and thus, knowledge of the dose-response relationship and influence on high-risk adenomas is limited. To address these issues, we conducted linear and nonlinear dose-response meta-analyses primarily based on prospective observational studies published up to July 2014 identified from PubMed and Embase. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated for total and supplemental calcium intake, respectively, using a random-effects model. For total calcium intake, summary RR for each 300 mg/day increase was 0.95 (95% CI = 0.92-0.98; I(2) = 45%; eight studies with 11,005 cases; range of intake = 333-2,229 mg/day). Evidence of nonlinearity was indicated: approximately, compared to 550 mg/day of total calcium intake, the summary RR was 0.92 (95% CI = 0.89-0.94) at 1,000 mg/day and 0.87 (95% CI = 0.84-0.90) at 1,450 mg/day (pnonlinearity < 0.01). Associations were stronger for high-risk adenomas (≥1 cm in diameter, (tubulo)villous histology, dysplasia, or multiplicity): approximately, compared to 550 mg/day of total calcium intake, the summary RR was 0.77 (95% CI = 0.74-0.81) at 1,000 mg/day and reduced to 0.69 (95% CI = 0.66-0.73) at 1,450 mg/da (pnonlinearity < 0.01). For supplemental calcium intake, summary RR of total adenoma risk for each 300 mg/day increase was 0.96 (95% CI = 0.93-0.99; I(2) = 0%; three studies with 4,548 cases; range of supplementation = 0-1,366 mg/day). In conclusion, calcium intake may continue to decrease the risk of adenomas, particularly high-risk adenomas, over a wide range of calcium intake.

Dairy products, calcium, and prostate cancer risk: a systematic review and meta-analysis of cohort studies.

BACKGROUND: Dairy product and calcium intakes have been associated with increased prostate cancer risk, but whether specific dairy products or calcium sources are associated with risk is unclear. OBJECTIVE: In the Continuous Update Project, we conducted a meta-analysis of prospective studies on intakes of dairy products and calcium and prostate cancer risk. DESIGN: PubMed and several other databases were searched up to April 2013. Summary RRs were estimated by using a random-effects model. RESULTS: Thirty-two studies were included. Intakes of total dairy products [summary RR: 1.07 (95% CI: 1.02, 1.12; n = 15) per 400 g/d], total milk [summary RR: 1.03 (95% CI: 1.00, 1.07; n = 14) per 200 g/d], low-fat milk [summary RR: 1.06 (95% CI: 1.01, 1.11; n = 6) per 200 g/d], cheese [summary RR: 1.09 (95% CI: 1.02, 1.18; n = 11) per 50 g/d], and dietary calcium [summary RR: 1.05 (95% CI: 1.02, 1.09; n = 15) per 400 mg/d] were associated with increased total prostate cancer risk. Total calcium and dairy calcium intakes, but not nondairy calcium or supplemental calcium intakes, were also positively associated with total prostate cancer risk. Supplemental calcium was associated with increased risk of fatal prostate cancer. CONCLUSIONS: High intakes of dairy products, milk, low-fat milk, cheese, and total, dietary, and dairy calcium, but not supplemental or nondairy calcium, may increase total prostate cancer risk. The diverging results for types of dairy products and sources of calcium suggest that other components of dairy rather than fat and calcium may increase prostate cancer risk. Any additional studies should report detailed results for subtypes of prostate cancer.

Calcium intake and colorectal cancer risk: dose-response meta-analysis of prospective observational studies.

Mechanistic and epidemiologic studies provide considerable evidence for a protective association between calcium intake and incident colorectal cancer (CRC). While the relationship has not been substantiated by short-duration randomized controlled trials (RCTs) of CRC, trials do show a benefit on adenomas, a precursor to CRC. To address some of this inconsistency, we conducted dose-response meta-analyses by sources of calcium intake, based on prospective observational studies published up to December 2013 identified from PubMed, Embase, and BIOSIS. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using a random-effects model. For total calcium intake, each 300 mg/day increase was associated with an approximately 8% reduced risk of CRC (summary RR = 0.92, 95% CI = 0.89-0.95, I(2) = 47%, 15 studies with 12,305 cases, intake = 250-1,900 mg/day, follow-up = 3.3-16 years). While the risk decreased less steeply in higher range of total calcium intake (P(non-linearity) = 0.04), the degree of curvature was mild and statistical significance of non-linearity was sensitive to one study. For supplementary calcium, each 300 mg/day increase was associated with an approximately 9% reduced risk of CRC (summary RR = 0.91, 95% CI = 0.86-0.98, I(2) = 67%, six studies with 8,839 cases, intake = 0-1,150 mg/day, follow-up = 5-10 years). The test for non-linearity was not statistically significant (P(non-linearity) = 0.11). In conclusion, both dietary and supplementary calcium intake may continue to decrease CRC risk beyond 1,000 mg/day. Calcium supplements and non-dairy products fortified with calcium may serve as additional targets in the prevention of CRC. RCTs of calcium supplements with at least 10 years of follow-up are warranted to confirm a benefit of calcium supplements on CRC risk.

Associations of maternal iron intake and hemoglobin in pregnancy with offspring vascular phenotypes and adiposity at age 10: findings from the Avon Longitudinal Study of Parents and Children.

BACKGROUND: Iron deficiency is common during pregnancy. Experimental animal studies suggest that it increases cardiovascular risk in the offspring. OBJECTIVE: To examine the relationship between maternal pregnancy dietary and supplement iron intake and hemoglobin, with offspring's arterial stiffness (measured by carotid-radial pulse wave velocity), endothelial function (measured by brachial artery flow mediated dilatation), blood pressure, and adiposity (measured by body mass index), test for mediation by cord ferritin, birth weight, gestational age, and child dietary iron intake, and for effect modification by maternal vitamin C intake and offspring sex. DESIGN: Prospective data from 2958 mothers and children pairs at 10 years of age enrolled in an English birth cohort, the Avon Longitudinal Study for Parents and Children (ALSPAC), was analysed. RESULTS: 2639 (89.2%) mothers reported dietary iron intake in pregnancy below the UK reference nutrient intake of 14.8 mg/day. 1328 (44.9%) reported taking iron supplements, and 129 (4.4%) were anemic by 18 weeks gestation. No associations were observed apart from maternal iron intake from supplements with offspring systolic blood pressure (-0.8 mmHg, 99% CI -1.7 to 0, P = 0.01 in the sample with all relevant data observed, and -0.7 mmHg, 99% CI -1.3 to 0, P = 0.008 in the sample with missing data imputed). CONCLUSION: There was no evidence of association between maternal pregnancy dietary iron intake, or maternal hemoglobin concentration (which is less likely to be biased by subjective reporting) with offspring outcomes. There was a modest inverse association between maternal iron supplement intake during pregnancy with offspring systolic blood pressure at 10 years.

Dietary compared with blood concentrations of carotenoids and breast cancer risk: a systematic review and meta-analysis of prospective studies.

BACKGROUND: Measurement errors in the dietary assessment of fruit and vegetable intake may attenuate associations with breast cancer risk and might explain the weak associations observed in epidemiologic studies. Carotenoid concentrations in blood are biomarkers of fruit and vegetable intake; however, no systematic assessment has compared dietary intake with blood concentrations of carotenoids and breast cancer risk. OBJECTIVE: We conducted a systematic review and meta-analysis of prospective studies of dietary intake and blood concentrations of carotenoids and breast cancer risk. DESIGN: We searched PubMed and several other databases for relevant studies up to 31 August 2011. Random-effects models were used to estimate summary estimates. RESULTS: Of the 6 dietary carotenoids assessed, only intake of ß-carotene was significantly associated with a reduced breast cancer risk (summary RR: 0.95; 95% CI: 0.91, 0.99; I(2): 0%) per 5000 µg/d (n = 10). In contrast, the summary RR for blood concentrations of carotenoids was 0.78 (95% CI: 0.61, 0.99; I(2): 53%) per 100 µg total carotenoids/dL (n = 7), 0.74 (95% CI: 0.57, 0.97; I(2): 43%) per 50 µg ß-carotene/dL (n = 13), 0.82 (95% CI: 0.73, 0.92, I(2): 3%) per 10 µg α-carotene/dL (n = 12), and 0.68 (95% CI: 0.52, 0.89; I(2): 0%) per 25 µg lutein/dL (n = 6). CONCLUSIONS: Blood concentrations of carotenoids are more strongly associated with reduced breast cancer risk than are carotenoids assessed by dietary questionnaires. Our results suggest that the use of certain biomarkers may clarify inconsistent and weak results between dietary intake and breast cancer risk.

Selenium and prostate cancer: systematic review and meta-analysis.

BACKGROUND: Prostate cancer is a growing public health problem. Several human studies have shown a potentially protective effect of selenium, but the conclusions from published reports are inconsistent. OBJECTIVE: The objective was to examine the evidence for relations between selenium intake, selenium status, and prostate cancer risk. DESIGN: This was a systematic review and meta-analysis of randomized controlled trials, case-control studies, and prospective cohort studies. The World Cancer Research Fund/American Institute for Cancer Research Continuous Update Project database was searched up to September 2010. The studies included reported measurements of selenium intake or status (plasma, serum, or toenail selenium), assessments of prostate cancer cases (number of events), and the RR in the adult population. Meta-analyses were performed, and study quality, heterogeneity, and small study effects were assessed. Dose-response meta-analyses were used, with restricted cubic splines and fractional polynomials for nonlinear trends, to investigate the association between selenium status and prostate cancer risk. RESULTS: Twelve studies with a total of 13,254 participants and 5007 cases of prostate cancer were included. The relation between plasma/serum selenium and prostate cancer in a nonlinear dose-response meta-analysis showed that the risk decreased with increasing plasma/serum selenium up to 170 ng/mL. Three high-quality studies included in the meta-analysis of toenail selenium and cancer risk indicated a reduction in prostate cancer risk (estimated RR: 0.29; 95% CI: 0.14, 0.61) with a toenail selenium concentration between 0.85 and 0.94 µg/g. CONCLUSION: The relation between selenium status and decreased prostate cancer risk was examined over a relatively narrow range of selenium status; further studies in low-selenium populations are required.

Vitamins, minerals, essential fatty acids and colorectal cancer risk in the United Kingdom Dietary Cohort Consortium.

The risk for colorectal cancer may be influenced by the dietary intake of various vitamins, minerals and essential fatty acids. We conducted a pooled analysis of dietary data collected using food diaries in seven prospective studies in the United Kingdom Dietary Cohort Consortium. Five hundred sixty-five cases of colorectal cancer were matched with 1,951 controls on study centre, age, sex and recruitment date. Dietary intakes of retinol, vitamin A, thiamin, riboflavin, vitamin B6, folate, vitamin B12, vitamin D, calcium, iron, magnesium, potassium, n - 6 fatty acids, n - 3 fatty acids and the ratio of n - 6 to n - 3 fatty acids were estimated and their associations with colorectal cancer examined using conditional logistic regression models, adjusting for exact age, height, weight, energy intake, alcohol intake, fiber intake, smoking, education, social class and physical activity. There were no statistically significant associations between colorectal cancer risk and dietary intake of any of the vitamins, minerals or essential fatty acids examined.

Meta-analyses of vitamin D intake, 25-hydroxyvitamin D status, vitamin D receptor polymorphisms, and colorectal cancer risk.

BACKGROUND: Our objective was to conduct a systematic review and meta-analysis of prospective studies on colorectal cancer (CRC) and vitamin D intake and 25-hydroxyvitamin D status, as part of the World Cancer Research Fund Continuous Update Project. We also aimed at conducting meta-analysis of all studies on CRC and vitamin D receptor (VDR) single-nucleotide polymorphisms. METHODS: Relevant studies were identified in PubMed (up to June 2010). Inclusion criteria were original and peer-reviewed publications with a prospective design (for studies on vitamin D intake or status). Random effects of dose-response meta-analyses were performed on cancer incidence. RESULTS: We observed inverse associations of CRC risk with dietary vitamin D [summary relative risk (RR) per 100 IU/day = 0.95, 95% CI: 0.93-0.98; 10 studies; range of intake (midpoints) = 39-719 IU/day] and serum/plasma 25-hydroxyvitamin D (RR per 100 IU/L = 0.96, 0.94-0.97; 6 studies; range = 200-1,800 IU/L), but not with total vitamin D (5 studies). Supplemental (2 studies; range = 0-600 IU/day) and total (4 studies; range = 79-732 IU/day) vitamin D intake and 25-hydroxyvitamin D status (6 studies; range = 200-1,800 IU/L) were inversely associated with colon cancer risk. We did not observe statistically significant associations between FokI, PolyA, TaqI, Cdx2, and ApaI VDR polymorphisms and CRC risk. The BsmI polymorphism was associated with a lower CRC risk (RR = 0.57, 0.36-0.89 for BB versus bb, 8 studies). CONCLUSIONS: These meta-analyses support the evidence of an inverse association between vitamin D intake, 25-hydroxyvitamin D status, and the BsmI VDR polymorphism and CRC risk. IMPACT: Improving vitamin D status could be potentially beneficial against CRC incidence.

Dietary iron intake during early pregnancy and birth outcomes in a cohort of British women.

BACKGROUND Iron deficiency during pregnancy is associated with adverse birth outcomes, particularly, if present during early gestation. Iron supplements are widely recommended during pregnancy, but evidence of their benefit in relation to infant outcomes is not established. This study was performed in the UK, where iron supplements are not routinely recommended during pregnancy, to investigate the association between iron intake in pregnancy and size at birth. METHODS From a prospective cohort of 1274 pregnant women aged 18-45 years, dietary intake was reported in a 24-h recall administered by a research midwife at 12-week gestation. Dietary supplement intake was ascertained using dietary recall and three questionnaires in the first, second and third trimesters. RESULTS Of the cohort of pregnant women, 80% reported dietary iron intake below the UK Reference Nutrient Intake of 14.8 mg/day. Those reported taking iron-containing supplements in the first, second and third trimesters were 24, 15 and 8%, respectively. Women with dietary iron intake >14.8 mg/day were more likely to be older, have a higher socioeconomic profile and take supplements during the first trimester. Vegetarians were less likely to have low dietary iron intake [odds ratio = 0.5, 95% confidence interval (CI): 0.4, 0.8] and more likely to take supplements during the first and second trimesters. Total iron intake, but not iron intake from food only, was associated with birthweight centile (adjusted change = 2.5 centiles/10 mg increase in iron, 95% CI: 0.4, 4.6). This association was stronger in the high vitamin C intake group, but effect modification was not significant. CONCLUSION There was a positive relationship between total iron intake, from food and supplements, in early pregnancy and birthweight. Iron intake, both from diet and supplements, during the first trimester of pregnancy was higher in vegetarians and women with a better socioeconomic profile.

High-dose vitamin C supplement use is associated with self-reported histories of breast cancer and other illnesses in the UK Women's Cohort Study.

OBJECTIVE: To determine whether frequent vitamin C supplement use is associated with healthier behaviours, and a history of cancer and other illnesses in UK women. DESIGN: The present cross-sectional analysis examines the odds of taking supplements containing vitamin C as recorded in 4 d food diaries, based on lifestyle characteristics and morbidity history self-reported by questionnaire. SETTING: A large national UK cohort study. SUBJECTS: A total of 12,453 women aged between 37 and 79 years. RESULTS: Women frequently taking supplements containing vitamin C, compared to those who did not, had healthier behaviours, including higher consumption of fruit and vegetables. Frequent high-dose vitamin C users (≥1000 mg) had a higher socio-economic status, visited alternative practitioners more often than family or private doctors, and were more likely to be ex-smokers and to drink little or no alcohol. Women who self-reported having had cancer (OR = 1·33, 95% CI 1·00, 1·76) or specifically breast cancer (OR = 1·70, 95% CI 1·14, 2·55), or reported a family history of cancer (OR = 1·16, 95% CI 0·95, 1·41) or breast cancer (OR = 1·26, 95% CI 1·01, 1·58) had increased odds of being frequent high-dose users after adjusting for sociodemographic and health behaviours. Women with personal or family histories of some cardiovascular or intestinal disorders were more likely to take supplements containing vitamin C, though not necessarily at high doses. CONCLUSIONS: High-dose vitamin C intake by UK women was associated with healthier behaviours and a history of breast cancer, total cancer and other illnesses. Consequences of high-dose vitamin C supplement intake are not clear at the population level.

The impact of high non-starch polysaccharide intake on serum micronutrient concentrations in a cohort of women.

OBJECTIVE: Many public health campaigns encourage increased fibre consumption, but short-term studies suggest that various components of dietary fibre inhibit the absorption of certain micronutrients including carotenoids. These do not take into account long-term adaptation to nutrient intake levels. We aimed to investigate the effect of non-starch polysaccharide (NSP) fibre on plasma micronutrient concentrations in a large free-living population consuming their usual diet. DESIGN: Prospective cohort study. Semi-weighed 4-day food diaries were analysed for micronutrient and NSP fibre intakes. Blood samples were taken and analysed for carotenoids, vitamin A, vitamin E, thiamine, riboflavin, vitamin B6, vitamin B12, folic acid, vitamin C and trace metals. SETTING: Participants in a large national cohort study who lived within 30 miles of Leeds. SUBJECTS: Two hundred and eighty-three middle-aged women. RESULTS: The association between NSP intake and plasma nutrient concentrations was assessed taking into account nutrient intakes and other dietary and lifestyle factors. Higher levels of NSP were not associated with lower plasma concentrations of the micronutrients measured, even allowing for the higher nutrient levels generally found in high-fibre foods. CONCLUSIONS: Amongst middle-aged women we have shown that current guidelines for increasing the population's NSP consumption can be safely applied. Such guidelines are unlikely to reduce serum micronutrient concentrations, although other, more vulnerable population groups may benefit from further investigation.