Diet and lifestyle characteristics associated with dietary supplement use in women

Adults with depressive symptoms have lower odds of dietary supplement use

OBJECTIVE

In this study, we aim to evaluate dietary supplement and complementary and alternative medicine (CAM) use in individuals with depressive symptoms. Furthermore, we conducted a comparative analysis of the usage of these agents among individuals with depressive symptoms, differentiating between those who were using antidepressants and those who were not. Additionally, we compared individuals with depressive symptoms who were not using antidepressants with participants who did not have depressive symptoms as well as individuals with depressive symptoms who were using antidepressants with individuals without depressive symptoms.

METHOD

The National Health and Nutrition Examination Survey 2007-2018 data was collected. Depressive symptoms were assessed using patient health questionnaire-9. Dietary supplement and antidepressants use was evaluated using Dietary Supplement Use and Prescription Medications Questionnaires.

RESULTS

31,445 participants, with 2870 (8.05%) having depressive symptoms were included. Participants with depressive symptoms had significantly lower odds of dietary supplement use compared with those without depressive symptoms (aOR = 0.827, 95% CI: 0.700,0.977, p = 0.026). Participants with depressive symptoms who were using antidepressants had significantly higher odds of dietary supplement (aOR = 1.290, 95% CI: 1.038,1.604, p = 0.022) compared with participants with depressive symptoms who were not using antidepressants. Furthermore, Participants with depressive symptoms who weren't using antidepressants had significantly lower odds of dietary supplement use (aOR = 0.762, 95% CI: 0.632,0.918, p = 0.005) compared with participants without depressive symptoms. In individuals with treated depressive symptoms compared to those without depressive symptoms, CAM use was significantly lower (aOR = 0.763, 95% CI = 0.598,0.973, p = 0.030).

CONCLUSION

Individuals with depressive symptoms have lower odds of dietary supplement use. Further studies are needed to replicate these findings and examine the underlying mechanisms for this association.

Association of serum docosahexaenoic acid and eicosapentaenoic acid levels with dietary intakes and supplement use during pregnancy: a prospective observational study

This study aimed to determine the association of serum docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) levels with dietary intakes and supplement use during pregnancy. This prospective observational study was conducted at a university hospital in Tokyo, Japan. Participants in their second and third trimesters were given a self-administered questionnaire assessing the frequency of DHA and EPA supplement use in the past month and a brief-type self-administered diet history questionnaire. Non-fasting serum DHA and EPA levels were analysed using gas chromatography. Differences in biomarkers by frequency of supplement use were determined using multiple comparison analyses, and Spearman's correlation coefficient was used to determine biomarkers and DHA and EPA intakes by food group. Of the 116 participants, 11 (9⋅5 %) in the second trimester and 18 (15⋅5 %) in the third trimester regularly used supplements (≥5 times per week). Regular users had higher serum DHA and EPA levels than never users in the second and third trimesters. Dietary DHA and EPA intake from fish and shellfish was positively correlated with serum DHA and EPA in the second and third trimesters. Supplement use ≥5 times per week and fish and shellfish intake were associated with high serum DHA and EPA levels.

Major dietary patterns in the United Kingdom Women's Cohort Study showed no evidence of prospective association with pancreatic cancer risk

Diet is a modifiable risk factor for pancreatic cancer. We hypothesized that specific dietary patterns would increase/decrease pancreatic cancer risk. We evaluated the association of dietary patterns with pancreatic cancer risk in the UK Women's Cohort Study. Dietary patterns were assessed at enrollment using: (1) self-reported practice of vegan/vegetarian dietary habits, (2) diet quality indices (World Health Organization Healthy Diet Indicator and Mediterranean Diet Score), and (3) principal component analysis-derived dietary patterns. The association of dietary patterns with pancreatic cancer incidence was quantified using Cox regression survival analysis. Over a median follow-up of 19 years of 35,365 respondents, there were 136 incident cases of pancreatic cancer. No association between dietary habits/quality and pancreatic cancer incidence was evident after adjustments (hazard ratio (95% confidence interval): self-reported omnivores vs vegan/vegetarian dietary habit: 1.13 (0.73-1.76); per-unit increase in World Health Organization Healthy Diet Indicator scores: 0.99 (0.91-1.09); per-unit increase in Mediterranean Diet Score: 0.92 (0.83-1.02). Similarly, no association of principal component analysis-derived dietary patterns with pancreatic cancer risk was evident ("prudent:" 1.02 [0.94-1.10]; ``meat-based:'' 1.00 [0.92-1.09]; ``fast-food, sugar-sweetened beverages, and carbohydrate-rich snacks:'' 0.96 [0.86-1.07]; ``cereal and dairy-rich:'' 1.04 [0.94-1.16], and ``low-diversity and lowfat:'' 1.00 [0.89-1.13]). In this prospective cohort of women, several major dietary patterns were of poor quality. There was no evidence of a prospective association between any of the dietary patterns explored and pancreatic cancer incidence.

Prevalence of dietary supplement use and knowledge, attitudes, practice (KAP) and associated factors in student population: A cross-sectional study

Dietary supplements (DSs) intake has been increasing worldwide despite no consensus evidence for the efficacy and safety of disease prevention, control, or treatment in nutrient-replete populations. This study aimed to determine the prevalence of DSs use, knowledge, attitude, and practice (KAP) and associated factors among university students in Jordan. A national cross-sectional study was carried over across universities in Jordan. Participants completed a valid and reliable online questionnaire (Cronbach's alpha = 0.802 and correlation coefficients between 0.72 and 0.26). Univariate analyses were used to determine the relationship between variables. Multivariable regression was carried out to identify significant factors contributing DSs usage. A total of 448 university students completed the study (73.7% females). More than half of the students used DSs (60.9%), with single-nutrient ingredient supplements being the most commonly used type. The primary motivators were maintaining health and most students reported no side effects associated with consumption. The results revealed poor knowledge, a negative attitude towards DSs usage among all participants, even non-users, and high-risk practices among the DSs users. Normal weight and overweight individuals were more likely to use DSs (OR:2.88, 95%CI:1.61-5.16, OR:1.95, 95%CI:1.01-3.79, respectively). Low and medium-family income categories were more likely to use DSs than those in the high-income category (OR: 0.04, 95%CI: 0.02-0.07, OR: 0.06, 95CI:0.03-0.11, respectively). Undergraduate students were more likely to use DSs than postgraduate students (OR:5.56, 95%CI:3.19-9.69). In this study, a high prevalence of DSs use was highlighted. The results suggest that nutrition education is required to improve awareness of DSs and to promote safe practices.

Food Supplement Use Differs from the Recommendations in Pregnant Women: A Multinational Survey

The aim was to investigate, among pregnant women, (1) the use of food supplements and (2) the awareness of food supplement recommendations and beliefs about food supplement use in four European countries: Finland, Italy, Poland, and the United Kingdom. The participants (n = 1804) completed an online questionnaire with predefined statements. Daily intakes of vitamins and minerals were calculated using uploaded pictures or weblinks of the supplement packages. Country differences were assessed. Most participants (91%) used at least one food supplement during pregnancy. A prenatal multivitamin was the most commonly used supplement type (84% of the users), and 75% of the participants thought consumption of multivitamin is recommended. Of the participants, 81% knew that folic acid is recommended during pregnancy while 58% knew the recommendation for vitamin D. In 19% of the supplement users, the daily safe upper intake limit of at least one nutrient was exceeded. Nevertheless, most participants agreed that they knew which supplements (91%) and doses of supplements (87%) needed to be used during pregnancy. To conclude, the majority of the participants used food supplements, but lower proportions knew and adhered to the recommended intakes. Between-country differences were observed in the use and knowledge of and beliefs regarding supplements. The results suggest a need for assessment and monitoring of supplement use in antenatal care to ensure appropriate use.

Dietary Supplement Use in Relation to Socio-Demographic and Lifestyle Factors, including Adherence to Mediterranean-Style Diet in University Students

The study aimed to examine socio-demographic and lifestyle determinants, including diet quality, of dietary supplement (DS) use among 2545 students who attended public universities in Warsaw. The data was collected using a self-administered health and lifestyle questionnaire and a 5-day dietary record method. Diet quality was assessed using a Mediterranean Diet Score. To determine the covariates of DS use, multivariate-adjusted logistic regression models with an estimation of odds ratios (ORs) and 95% confidence intervals (95% CIs) were used. The results showed that 41% of participants were DS users. The following predictors of DS use were identified: gender (male vs. female; OR:0.62, 95% CI:0.50–0.79), physical activity (high vs. low; OR:1.79, 95% CI:1.45–2.20), BMI (≥25 vs. 18.5–24.9 kg/m²; OR:0.77, 95% CI:0.61–0.98), cigarette smoking (yes vs. no; OR:0.67, 95% CI:0.52–0.86), and presence of chronic diseases (yes vs. no; OR:2.37, 95% CI:1.89–2.98). Moreover, higher nutritional knowledge, special diet usage, eating more meals/day, and fortified food consumption were determinants of DS use. Adherence to the Mediterranean-style diet was positively associated with DS use, a 1-score increment was associated with a 10% (p-trend = 0.011) higher probability of DS usage. Given that the use of vitamins and/or minerals is common among university students and their users are characterized by eating a higher quality diet, investigating the contribution of DS in overall dietary nutrient intake warrants further study.

Association between neighbourhood deprivation, fetal growth, small-for-gestational age and preterm birth: a population-based prospective cohort study

OBJECTIVE

To study the associations between neighbourhood deprivation and fetal growth, including growth in the first trimester, and adverse pregnancy outcomes.

DESIGN

Prospective cohort study.

SETTING

The Netherlands, Rotterdam.

PARTICIPANTS

8617 live singleton births from the Generation R cohort study.

EXPOSITION

Living in a deprived neighbourhood.

MAIN OUTCOME MEASURES

Fetal growth trajectories of head circumference, weight and length.

SECONDARY OUTCOMES MEASURES

Small-for-gestational age (SGA) and preterm birth (PTB).

RESULTS

Neighbourhood deprivation was not associated with first trimester growth. However, a higher neighbourhood status score (less deprivation) was associated with increased fetal growth in the second and third trimesters (eg, estimated fetal weight; adjusted regression coefficient 0.04, 95% CI 0.02 to 0.06). Less deprivation was also associated with decreased odds of SGA (adjusted OR 0.91, 95% CI 0.86 to 0.97, p=0.01) and PTB (adjusted OR 0.89, 95% CI 0.82 to 0.96, p=0.01).

CONCLUSIONS

We found an association between neighbourhood deprivation and fetal growth in the second and third trimester pregnancy, but not with first trimester growth. Less neighbourhood deprivation is associated with lower odds of adverse pregnancy outcomes. The associations remained after adjustment for individual-level risk factors. This supports the hypothesis that living in a deprived neighbourhood acts as an independent risk factor for fetal growth and adverse pregnancy outcomes, above and beyond individual risk factors.

Nutrient intakes from supplement and factors associated with supplement use among breast cancer survivors: A cross-sectional study

OBJECTIVE

We investigated the contribution of supplement use to total nutrient intake, the prevalence of inadequate nutrient intake and the factors associated with supplement use among breast cancer survivors.

METHODS

A total of 701 Korean breast cancer survivors were included. We calculated the contribution of dietary supplements to total nutrient intake and the proportion of the population below the estimated average requirements (EARs) or exceeding the tolerable upper intake levels (ULs). Stepwise logistic regression was used to identify factors associated with dietary supplement use.

RESULTS

A total of 66.5% of the survivors used dietary supplements, with multivitamins and minerals being the most commonly consumed ones. The per cent contribution of supplement to the total intake was the highest for vitamin C. 28.2%-55.4% of the non-users consumed below the EAR of riboflavin, folate and calcium; 6.1%, 4.9% and 6.5% of the supplement users consumed above the UL of vitamins A and C, and iron, respectively. Supplement users had higher education levels or longer survival time.

CONCLUSION

66.5% of Korean breast cancer survivors used dietary supplements. A higher education level or prolonged survival time was associated with higher use of dietary supplements.

Consumers' Information-Seeking Behaviors on Dietary Supplements

Background

Consumers are advised to seek information about dietary supplements (DS) before using them; little is known concerning whether this recommendation is heeded.

Objective

The objectives of this pilot study were to investigate whether users of DS seek information about these products before using them and particularly whether such information is sought from health-care professionals (HCPs).

Methods

Surveys administered face-to-face to adult consumers at three venues in New York City.

Results

Between November 2017 and October 2018, 199 consumers were surveyed. Of the 139 (70%) DS users, 104 (75%) used at least one DS that was not prescribed/recommended by an HCP. Of those, 88 (85%) reported seeking information about DS before using them and two (2%) noted that for some they do and for some they do not. The source of information most frequently used was the Internet (76; 84%). Pharmacists, dietitians/nutritionists, and medical doctors were reported to be a source of information by seven (8%), six (7%), and five (6%) of the respondents, respectively. DS were most commonly purchased at a pharmacy (76; 54%). Of the 199 participants, 111 (56%) perceived DS to be “very safe” or “safe,” while 20 (10%) reported that DS were “unsafe” or “very unsafe”; 60 (30%) participants were “neutral.”

Conclusion

Although most DS users sought information prior to using them, the majority did so by using the Internet and only a few consulted with an HCP. HCPs should be proactive in educating consumers about the importance of consulting with them prior to using these products.

Cobalamin is produced by Acetobacter pasteurianus DSM 3509

Only a few cobalamin-producing bacterial species are known which are suitable for food fermentations. The strain of Acetobacter pasteurianus DSM 3509 was found to have the capability to synthesize cobalamin. A survival test and a preliminary genetic study of the gene of uroporphyrinogen-III synthase indicated the ability to synthesize cobalamin. By a modified microbiological assay based on Lactobacillus delbrueckii ssp. lactis DSM 20355, 4.57 ng/mL of cyanocorrinoids and 0.75 ng/mL of noncorrinoid growth factors were detected. The product extracted and isolated by immunoaffinity chromatography in its cyanide form had the similar UV spectrum as standard cyanocobalamin and Coα-[α-(7-adenyl)]-(Coβ-cyano) cobamide also known as pseudovitamin B₁₂ produced by Lactobacillus reuteri DSM 20016. The chromatographically separated product of A. pasteurianus was subjected to mass spectrometrical analysis. There, its fragmentation pattern turned out to be equivalent to that of cyanocobalamin also produced by Propionibacterium freudenreichii ssp. freudenreichii DSM 20271 and clearly differs from pseudovitamin B₁₂. Due to the presence of this species in several food applications, there might be cobalamin residues in food fermented with these bacteria.

Fish oil supplement use in New Zealand: A cross-sectional survey

OBJECTIVE

The aims of the survey were to determine: (i) the percentage of fish oil supplement users in a sample population; (ii) why people take fish oil supplements; (iii) where fish oil supplements are stored as well as the average daily dosage; (iv) what dietary and lifestyle behaviours are associated with fish oil supplement use.

DESIGN

An online cross-sectional survey.

SETTING

New Zealand.

RESPONDENTS

A total of 334 New Zealand residents over the age of 18.

RESULTS

Fish oil supplements were taken by 21.9% of respondents. Reasons for taking fish oil supplements were - 72.6% for 'general well-being', 54.8% to 'improve brain function', 31.5% for 'pain/inflammation', 12.3% to 'lower cholesterol levels' and 11% for 'a dietary insufficiency'. Approximately 26% of fish oil users reported taking a dose of fish oil supplements that would meet the recommended daily intake of 400-600 mg combined docosahexaenoic acid and eicosapentaenoic acid, and only 6.8% of fish oil users reported storing their fish oil supplements in the refrigerator. After controlling for other characteristics including age, gender, ethnicity and body mass index, fish oil supplementation use was most likely among respondents who already eat oily fish and least likely in respondents who regularly eat nuts and seeds.

CONCLUSIONS

Fish oil supplements are a commonly used supplement in New Zealand, yet questions remain about the role of these supplements in improving health outcomes. Safety issues related to manufacturing and storage conditions indicate that there is an urgency in answering these questions.

The balance between food and dietary supplements in the general population

In the past, vitamins and minerals were used to cure deficiency diseases. Supplements nowadays are used with the aim of reducing the risk of chronic diseases of which the origins are complex. Dietary supplement use has increased in the UK over recent decades, contributing to the nutrient intake in the population, but not necessarily the proportion of the population that is sub-optimally nourished; therefore, not reducing the proportion below the estimated average requirement and potentially increasing the number at risk of an intake above the safety limits. The supplement nutrient intake may be objectively monitored using circulation biomarkers. The influence of the researcher in how the supplements are grouped and how the nutrient intakes are quantified may however result in different conclusions regarding their nutrient contribution, the associations with biomarkers, in general, and dose-response associations specifically. The diet might be sufficient in micronutrients, but lacking in a balanced food intake. Since public-health nutrition guidelines are expressed in terms of foods, there is potentially a discrepancy between the nutrient-orientated supplement and the quality of the dietary pattern. To promote health, current public-health messages only advocate supplements in specific circumstances, but not in optimally nourished populations.

Vitamin C Intake and Risk of Prostate Cancer: The Montreal PROtEuS Study

Background: Vitamin C is a reducing agent and free radical scavenger, acting as antioxidant in plasma membranes and within cells. Based on these properties, a role for vitamin C in cancer incidence has been suspected. There are as yet few large population-based studies focusing on prostate cancer, with the preponderant evidence leaning toward the absence of an association. Nevertheless, many previous studies overlooked prostate cancer aggressiveness, as well as screening and detection issues, which could bias potential associations.

Methods: The Prostate Cancer and Environment Study (PROtEuS) is a population-based case-control study conducted in Montreal, Canada. In-person interviews, conducted with 1,916 histologically confirmed prostate cancer cases and 1,985 population controls, elicited information on a wide range of socio-demographic, lifestyle, and medical factors, including PSA screening. Usual frequency of consumption of 63 food items two years prior to diagnosis/interview was collected, along with use of dietary supplements. Odds ratios (OR) and 95% confidence intervals (CI) between vitamin C intake and prostate cancer were estimated using logistic or polytomous regression, adjusting for potential confounders.

Results: We observed no association between dietary intakes of vitamin C (OR for upper vs. lower tertile: 0.95, 95%CI 0.77, 1.18), estimated using the residual method to account for energy intake, or between regular use of vitamin C supplements and/or multivitamins (OR 0.90, 95%CI 0.76–1.05), and overall prostate cancer. Analyses considering disease aggressiveness, or restricted to subjects recently screened with PSA, thereby limiting the potential for undiagnosed cancers in non-cases, generated results consistent with those from the main analyses.

Conclusion: Our findings document the absence of an association between recent dietary vitamin C intake, or supplementation, and prostate cancer incidence overall or prostate cancer grade at diagnosis. Based on this, and other available evidence, vitamin C intake does not seem to hold promises with regard to prostate cancer prevention.

Overfed but undernourished: recognizing nutritional inadequacies/deficiencies in patients with overweight or obesity

Overweight and obesity are highly prevalent throughout the world and can adversely affect the nutritional status of individuals. Studies have shown that many people with obesity have inadequate intake of iron, calcium, magnesium, zinc, copper, folate and vitamins A and B₁₂, likely as a result of poor diet quality. Nutritional inadequacies or deficiencies may also occur due to altered pharmacokinetics in the individual with obesity and due to interactions in those with overweight or obesity with various pharmaceuticals. However, it has been demonstrated that the adult population in the United States as a whole is deficient in certain micronutrients as a result of the availability and overconsumption of high-calorie, low-nutrient processed foods. Poor nutrition may contribute to the development of certain chronic conditions, such as type 2 diabetes, which is already more prevalent in those with obesity. Clinicians need to be aware of these gaps, particularly in those individuals with obesity who are undergoing bariatric surgery or taking pharmaceutical products long term to facilitate weight loss. Patients with overweight or obesity likely struggle to achieve a balanced diet and may benefit from consultation with a dietitian. Along with providing recommendations for healthy eating and exercise, supplementation with specific micronutrients or multivitamins should be considered for individuals at the highest risk for or with established deficiencies. Further research is needed to understand the factors underlying nutritional inadequacies in individuals with overweight or obesity, as well as the outcomes of treatment strategies employed to address them.

Dietary supplement use, perceptions, and associated lifestyle behaviors in undergraduate college students, student-athletes, and ROTC cadets

OBJECTIVE

To identify the prevalence of dietary supplement (DS) use, perceptions of DS efficacy, and lifestyle behaviors of DS users and non-users.

PARTICIPANTS

Undergraduate students, student-athletes, and ROTC cadets at a Midwestern University between September 2014 and January 2015.

METHODS

A cross-sectional online survey was administered. Analysis included descriptive statistics, chi-square, and independent sample t-tests.

RESULTS

At least 50% of respondents from each group reported DS use. Users generally reported favorable perceptions of efficacy. Undergraduate student DS users reported more exercise and more healthful dietary habits compared to non-users; however, nearly 72% of undergraduates who reported tobacco use also reported DS use. Less significant differences were observed in the student-athlete and cadet samples.

CONCLUSIONS

DS use is common on college campuses, and many DS users report favorable perceptions of efficacy. With the exception of tobacco use, collegiate DS users generally report lifestyles that are as healthy or healthier than non-users.

Dietary Supplement Use among Australian Adults: Findings from the 2011-2012 National Nutrition and Physical Activity Survey

(1) Background: Supplement use is prevalent worldwide; however, there are limited studies examining the characteristics of people who take supplements in Australia. This study aimed to investigate the demographics, lifestyle habits and health status of supplement users; (2) Methods: Adults aged >19 years (n = 4895) were included from the 2011-2012 National Nutrition and Physical Activity Survey (NNPAS). A supplement user was defined as anyone who took one or more supplements on either of two 24-h dietary recalls. Poisson regression was used to estimate the prevalence ratio (PR) of supplement use, according to demographics, lifestyle characteristics and health status of participants; (3) Results: Supplement use was reported by 47% of women and 34% of men, and supplement use was higher among older age groups, among those with higher education levels and from areas reflecting the least socioeconomic disadvantaged. An association was found between blood pressure and supplement use; (4) Conclusions: A substantial proportion of Australians take supplements. Further investigation into the social, psychological and economic determinants that motivate the use of supplements is required, to ensure appropriate use of supplements among Australian adults.

Associations between lifestyle factors and an unhealthy diet

Background

: Unhealthy dietary patterns have been associated with other unhealthy lifestyle factors such as smoking and physical inactivity. Whether these associations are similar in high- and low-educated individuals is currently unknown.

Methods

We used information of the EPIC-NL cohort, a prospective cohort of 39 393 men and women, aged 20-70 years at recruitment. A lifestyle questionnaire and a validated food frequency questionnaire were administered at recruitment (1993-97). Low adherence to a Mediterranean-style diet was used to determine an unhealthy dietary pattern. Lifestyle-related factors included body mass index, waist circumference, smoking status, physical activity level, dietary supplement use and daily breakfast consumption. Multivariate logistic regression analyses were performed for the total population and by strata of educational level.

Results

In total 30% of the study population had an unhealthy dietary pattern: 39% in the lowest educated group and 20% in the highest educated group. Physical inactivity, a large waist circumference, no dietary supplement use and skipping breakfast were associated with an unhealthy dietary pattern in both low and high educated participants. Among low educated participants, current smokers had a greater odds of an unhealthy diet compared with never smokers: OR 1.42 (95% CI: 1.25; 1.61). This association was not observed in the high educated group.

Conclusions

Most associations between lifestyle-related factors and unhealthy diet were consistent across educational levels, except for smoking. Only among low educated participants, current smokers reported an unhealthier dietary pattern in comparison to never smokers. These results can be used in the development of targeted health promotion strategies.

Complementarity in dietary supplements and foods: are supplement users vegetable eaters?

Background: The consumption of fruits, vegetables, and dietary supplements correlate. Most previous studies have aimed to identify the determinants of supplement uses or the distinct features of supplement users; this literature lacks a discussion on dietary supplement consumption as a predictor of fruit and vegetable consumption. Objective: This study examines how dietary supplement consumption correlates with fruit and vegetable consumption by combining scanner data and surveys of Korean household grocery shopping. Methods: Propensity score matching (PSM) is used to identify the relationship between dietary supplement consumption and fruit and vegetable consumption in a household. A logit regression using supplement consumption as the dependent variable is used. Then, the supplement takers (the treatment group) are matched with non-takers (the control group) based on the propensity scores estimated in the logit regression. The fruit and vegetable consumption levels of the groups are then compared. Results: We found that dietary supplement use is associated with higher fruit and vegetable consumption. This supports the health consciousness hypothesis based on attention bias, availability heuristics, the focusing effect, and the consumption episode effect. It rejects the health substitute hypothesis based on economic substitutes and mental accounting. Conclusions: Future research on the health benefits of dietary supplements should address the complementary consumption of fruits/vegetables and their health benefits to avoid misstating the health effects of supplements.

Exploring beliefs about dietary supplement use: focus group discussions with Dutch adults

OBJECTIVE

Although dietary supplement use is increasing in Europe and the USA, little research involving adults' beliefs regarding dietary supplements has been conducted. Therefore, the present study aimed to explore and compare users' and non-users' beliefs towards dietary supplements.

DESIGN

Thirteen focus group discussions were conducted of which seven groups were dietary supplement users and six groups were non-users. Based on the socio-cognitive factors of the Integrated Change Model, a semi-structured topic guide was set up. The discussions were audio-recorded and subjected to qualitative content analysis, applying the framework approach.

SETTING

Data were collected in Maastricht, the Netherlands, in 2014 and 2015.

SUBJECTS

In total fifty-six individuals participated in the study, of whom twenty-eight were dietary supplement users and twenty-eight non-users. The average age of participants was 42·9 years.

RESULTS

Dietary supplement users' attitude beliefs were mainly related to mental and physical health enhancement, illness prevention and curative health benefits. Users were critical of the nutritional knowledge of health professionals and of the quality of food products. Non-users were convinced that the human body does not need any support and that regular food is enough to cover one's nutritional needs. Users and non-users held comparable beliefs regarding the definition and risks of dietary supplements, and perceived social influences.

CONCLUSIONS

In their decision about dietary supplement use, both groups were guided by their own convictions to a great extent. Both groups would benefit from improved understanding of the health effects of dietary supplements to improve informed decision making.

Predicting healthy eating intention and adherence to dietary recommendations during pregnancy in Australia using the Theory of Planned Behaviour

This study aims to aid in the development of more effective healthy eating intervention strategies for pregnant women by understanding the relationship between healthy eating intention and actual eating behaviour. Specifically, the study explored whether Theory of Planned Behaviour (TPB) constructs [attitude, subjective-norm, perceived-behavioural-control (PBC)] and additional psychosocial variables (perceived stress, health value and self-identity as a healthy eater) are useful in explaining variance in women's 1) intentions to consume a healthy diet during pregnancy and 2) food consumption behaviour (e.g. adherence to food group recommendations) during pregnancy. A cross-sectional sample of 455 Australian pregnant women completed a TPB questionnaire as part of a larger comprehensive web-based nutrition questionnaire. Women's perceived stress, health value and self-identity as a healthy eater were also measured. Dietary intake was assessed using six-items based on the 2013 Australian Dietary Guidelines. Hierarchical multiple linear regression models were estimated (significance level <0.05), which explained 70% of the variance in healthy eating intention scores and 12% of the variance in adherence to food group recommendations. TPB constructs explained 66% of the total variance in healthy eating intention. Significant predictors of stronger healthy eating intention were greater PBC and subjective norm, followed by positive attitude and stronger self-identity as a healthy eater. Conversely, TPB constructs collectively explained only 3.4% of total variance in adherence to food group recommendations. These findings reveal that the TPB framework explains considerable variance in healthy eating intention during pregnancy, but explains little variance in actual food consumption behaviour. Further research is required to understand this weak relationship between healthy eating intention and behaviour during pregnancy. Alternative behavioural frameworks, particularly those that account for the automatic nature of most dietary choices, should also be considered.

Why do Dutch people use dietary supplements? Exploring the role of socio-cognitive and psychosocial determinants

BACKGROUND

In the Netherlands, the prevalence of dietary supplement use has doubled (from 17 to 40 per cent) since the 1980s. Yet, limited data is available on which socio-cognitive factors are associated with dietary supplement use. Therefore, the purpose of the study is to explain dietary supplement use with determinants deriving from the Integrated Change Model (ICM) and from formative research.

METHOD/DESIGN

Socio-cognitive and psychosocial factors were measured among users and non-users of dietary supplements in a longitudinal survey study, with measurements at baseline (N = 1448) and at one-month follow-up (N = 1161). Negative binomial regression analysis was applied to de data.

RESULTS

Intention emerged as the main predictor of dietary supplement use (OR = 1.99). Further predictors of dietary supplement use with smaller effect-sizes were: health regulatory focus (promotion, OR = 1.46), social modelling (OR = 1.44), attitude (pros, OR = 1.37), attitude (cons, OR = 0.87), health locus of control (OR = 0.77), and risk perception (chance of getting ill, OR = 1.22).

CONCLUSIONS

Individuals tend to use dietary supplements if they are promotion oriented, notice dietary supplement users in their social environment, estimate their chances of getting ill higher, and have positive attitudes towards dietary supplements. In contrast, non-users believe that external factors affect their health, and hold negative attitudes towards dietary supplements.

PRACTICAL IMPLICATIONS

Mapping out individuals' socio-cognitive profile may contribute to the development of online health communication. Based on socio-cognitive and demographical factors, personalised advice can be given about dietary supplement use.

Nutritional supplements use in high-performance athletes is related with lower nutritional inadequacy from food

BACKGROUND

The use of nutritional supplements (NS) among athletes is widespread. However, little is known about the relationship between nutritional adequacy and NS usage. The aims of this study were to evaluate the NS usage and to compare the nutritional intake from food and prevalence of micronutrient inadequacy (PMI) between NS users and non-users.

METHODS

Portuguese athletes from 13 sports completed an NS usage questionnaire and a semi-quantitative food-frequency questionnaire assessing information over the previous 12 months. The estimated average requirement cut-point method was used to calculate PMI. General linear models were used to compare nutritional intake and NS usage. Chi-squared tests and logistic regression were performed to study, respectively, relationships and associations between PMI and NS usage.

RESULTS

From the 244 athletes (66% males, 13-37 years), 64% reported NS usage. After adjustment, NS users showed a higher intake from food (p < 0.05), for at least 1 gender, for energy, and for 7 of the 17 studied nutrients. The highest PMI were seen for vitamins D and E, calcium, folate, and magnesium. After adjustment, NS users, irrespective of gender, reported lower PMI for calcium (OR = 0.28, 95%CI: 0.12-0.65), and female users for magnesium (OR = 0.06, 95%CI: 0.00-0.98).

CONCLUSION

Athletes using NS reported a higher nutritional intake from food, and a lower PMI for several nutrients. Perhaps, those who were taking NS were probably the ones who would least benefit from it.

Modifiable risk factors for the prevention of bladder cancer: a systematic review of meta-analyses

Each year, 430,000 people are diagnosed with bladder cancer. Due to the high recurrence rate of the disease, primary prevention is paramount. Therefore, we reviewed all meta-analyses on modifiable risk factors of primary bladder cancer. PubMed, Embase and Cochrane database were systematically searched for meta-analyses on modifiable risk factors published between 1995 and 2015. When appropriate, meta-analyses (MA) were combined in meta-meta-analysis (MMA). If not, the most comprehensive MA was selected based on the number of primary studies included. Probability of causation was calculated for individual factors and a subset of lifestyle factors combined. Of 1496 articles identified, 5 were combined in MMA and 21 were most comprehensive on a single risk factor. Statistically significant associations were found for current (RR 3.14) or former (RR 1.83) cigarette smoking, pipe (RR 1.9) or cigar (RR 2.3) smoking, antioxidant supplementation (RR 1.52), obesity (RR 1.10), higher physical activity levels (RR 0.86), higher body levels of selenium (RR 0.61) and vitamin D (RR 0.75), and higher intakes of: processed meat (RR 1.22), vitamin A (RR 0.82), vitamin E (RR 0.82), folate (RR 0.84), fruit (RR 0.77), vegetables (RR 0.83), citrus fruit (RR 0.85), and cruciferous vegetables (RR 0.84). Finally, three occupations with the highest risk were tobacco workers (RR 1.72), dye workers (RR 1.58), and chimney sweeps (RR 1.53). The probability of causation for individual factors ranged from 4 to 68 %. The combined probability of causation was 81.8 %. Modification of lifestyle and occupational exposures can considerably reduce the bladder cancer burden. While smoking remains one of the key risk factors, also several diet-related and occupational factors are very relevant.

Use of nutritional supplements by Danish elite athletes and fitness customers

The nutritional supplement (NS) industry is one of the fastest growing in the world, and NS use in Denmark is among the highest in Europe. However, the exact use in elite athletes and fitness customers targeted for doping control is unknown. Information from 634 doping control forms obtained in 2014 was evaluated (elite athletes: n = 361; fitness customers: n = 273). The majority of female (92.6%) and male (85.0%) elite athletes and female (100.0%) and male (94.0%) fitness customers declared using one or more NS. The use of non-ergogenic NS was more prevalent in women than in men and in younger (15-34 years) compared with older (35-49 years) subjects, but it was less prevalent in intermittent compared with endurance and power/strength sports. Additionally, fitness customers who tested positive for doping also reported using more NS than subjects testing negative, indicating an association between NS and doping abuse. The present results demonstrate a very high prevalence of NS usage in both elite athletes and fitness customers. This highlights the importance of a strong national regulation of NS to avoid contamination of NS with doping substances.

Determinants of dietary supplement use – healthy individuals use dietary supplements

The prevalence of dietary supplement use varies largely among populations, and previous studies have indicated that it is high in the Danish population compared with other European countries. The diversity in supplement use across countries indicates that cultural and environmental factors could influence the use of dietary supplements. Only few studies investigating the use of dietary supplements have been conducted in the Danish population. The present cross-sectional study is based on 54 948 Danes, aged 50–64 years, who completed self-administrated questionnaires on diet, dietary supplements and lifestyle between 1993 and 1997. A health index including smoking, physical activity, alcohol and diet, and a metabolic risk index including waist circumference, urinary glucose and measured hypertension were constructed. Logistic regression was used to investigate these determinants in relation to the intake of dietary supplements. We found that 71 % of the participants were dietary supplement users; female sex, older age groups and higher educated participants were more likely to be users of any dietary supplements. One additional point in the health index was associated with 19, 16 and 9 % higher likelihood of being user of any, more common and less common supplements, respectively. In the metabolic risk index, one additional point was associated with 17 and 16 % lower likelihood of being user of any supplement and more common supplements, respectively. No significant association was found for less common supplement use. In conclusion, those with the healthiest lifestyle were more likely to use dietary supplements. Thus, lifestyle and dietary composition should be considered as confounders on supplement use and health outcomes.

Cod liver oil supplement consumption and health: cross-sectional results from the EPIC-Norfolk cohort study

Supplement users (SU) make healthy lifestyle choices; on the other hand, SU report more medical conditions. We hypothesised that cod liver oil (CLO) consumers are similar to non-supplement users, since CLO use might originate from historical motives, i.e., rickets prevention, and not health consciousness. CLO consumers were studied in order to identify possible confounders, such as confounding by indication. The European Prospective Investigation into Cancer (EPIC) investigates causes of chronic disease. The participants were 25,639 men and women, aged 40–79 years, recruited from general practices in Norfolk, East-Anglia (UK). Participants completed questionnaires and a health examination between 1993 and 1998. Supplement use was measured using 7-day diet diaries. CLO was the most common supplement used, more prevalent among women and associated with not smoking, higher physical activity level and more favourable eating habits. SU had a higher occurrence of benign growths and bone-related diseases, but CLO was negatively associated with cardiovascular-related conditions. Although the results of SU characteristics in EPIC-Norfolk are comparable with studies worldwide, the CLO group is different from SU in general. Confounding by indication takes place and will need to be taken into account when analysing prospective associations of CLO use with fracture risk and cardiovascular diseases.

Contribution of cod liver oil-related nutrients (vitamins A, D, E and eicosapentaenoic acid and docosahexaenoic acid) to daily nutrient intake and their associations with plasma concentrations in the EPIC-Norfolk cohort

Background

Total nutrient intake (TNI) is intake from food and supplements. This provides an assessment of nutrient adequacy and the prevalence of excessive intake, as well as the response with respect to biomarkers. Cod liver oil (CLO) is the most frequently consumed supplement in the UK, containing nutrients that might have varying influences on health. We calculated TNI for vitamins A, D and E, as well as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and assessed associations with the respective blood concentrations.

Methods

Seven-day diet diaries and blood samples were taken from two subsets of the European Prospective Investigation into Cancer (EPIC-Norfolk) cohort (age range 39–79 years; n = 1400 for vitamin D; n = 6656 for remaining nutrients). TNI was calculated for the subgroups: nonsupplement users, those consuming the nutrient in supplement form and those consuming a supplement without this nutrient.

Results

CLO-related nutrients were supplemented by 15%–33%, which approximately doubled median intakes. Almost everyone in the supplement + vitamin A group reached the estimated average requirement; however, guideline levels were likely to be exceeded. Partial correlations between intake of vitamins A and D and biomarkers were low and modestly strengthened by the inclusion of supplement sources (correlation = 0.01–0.13). Correlations between biomarker and TNI of vitamin E and EPA+DHA were in the range 0.40–0.46; however, vitamin E exceeding food intake resulted in attenuated coefficients. Linear associations between food or TNI EPA+DHA and plasma were weak but consistent across subgroups.

Conclusions

CLO-related nutrients contribute substantially to nutrient intake, with a risk of over-consumption. Apart from EPA+DHA, biomarker data suggest that CLO-related nutrients in supplements are not linearly associated with vitamin status.

Opposites don't attract: high spouse concordance for dietary supplement use in the European Prospective Investigation into Cancer in Norfolk (EPIC-Norfolk) cohort study

OBJECTIVE

Dietary supplements are commonly consumed but may not be beneficial for everyone. It is known that supplement users have healthy behaviour characteristics but until now concordance between spouses living in the same household has not been investigated and concordance may be an important behavioural determinant.

DESIGN

Prospective cohort study, cross-sectional data analysis.

SETTING

European Prospective Investigation into Cancer in Norfolk (EPIC-Norfolk) in the UK, recruitment between 1993 and 1998.

SUBJECTS

Married (or living as married) participants sharing a household, who attended a health examination and completed a 7 d diet diary were included in the analysis (n 11 060). The age range was 39-79 years.

RESULTS

Nearly 75 % of the households in EPIC-Norfolk were concordant in their supplement use, with 46·7 % not using supplements and 27·0 % using supplements. Concordance increased with age; the percentage of concordant couples varied less by other sociodemographic characteristics. Participants who had a spouse who used a supplement were nearly nine times more likely to use a supplement (unadjusted). Depending on participants' sex and type of supplement used, odds ratios for 'supplement use by spouse' in the prediction of participants' supplement use varied between 6·2 and 11·7 adjusted for participants' age, smoking status, BMI, social class, education level and physical activity.

CONCLUSIONS

'Supplement use by spouse' is an independent and the strongest predictor of participants' supplement use. This phenomenon can be useful in the design of studies and health interventions; or when assessing risk of excessive intake from dietary supplements.

General supplement use, subsequent use and cancer risk in the UK Women's Cohort Study

BACKGROUND/OBJECTIVES

To determine whether general dietary supplement use is associated with cancer risk in UK women and to estimate risks related to use at one and two recording points.

SUBJECTS/METHODS

Cox's proportional hazard regression models were used to estimate cancer risks for 32 665 middle-aged women in the UK Women's Cohort Study relating to any current supplement use recorded in a baseline questionnaire. During a median follow-up of 15 years, there were 3936 registered cancer incidences, including 1344 breast, 429 smoking-related and 362 colorectal cancers. Cancer risks for 12 948 of these women, who also completed questionnaires on average 4.4 years later, were estimated in relation to any supplement use at both time points (1527 cancers, including 561 breast, 131 smoking-related and 141 colorectal cancers). Adjustments were made for baseline confounders.

RESULTS

Total smoking-related cancers were associated with baseline supplement use (hazard ratio (HR)=1.41, 95% confidence interval (CI): 1.10, 1.81) compared with non-use, but not associated with use at both recording points (HR=1.29; 95% CI: 0.78, 2.13) compared with use at neither. There was no evidence of the associations between total, colorectal or breast cancers and baseline supplement use, or use at both recording points. In sub-analyses, no significant associations with breast cancer were found for premenopausal or postmenopausal baseline users, or similarly for use at both points (HR=1.35, 95% CI: 0.91, 2.01; and HR=0.93, 95% CI: 0.68, 1.26, respectively).

CONCLUSIONS

There was evidence that general supplement use was associated with increased smoking-related cancer risk, but there was no evidence of associations with total, colorectal and breast cancers.

The use of dietary supplements among older persons in southern Germany - results from the KORA-age study

OBJECTIVES

Current population-based surveys in Europe on the prevalence of dietary supplement (DS) use in older individuals are scarce. The aim of the present study was to investigate patterns, prevalence and determinants of non-herbal DS use in aged subjects. Furthermore, the intake amounts of vitamins and minerals from supplements were assessed.

DESIGN

Cross-sectional.

SETTING

Data on supplement use were available from an age- and sex-stratified random sample of the German population-based KORA (Cooperative Health Research in the Region of Augsburg)-Age study.

PARTICIPANTS

1,079 persons who were born in or before the year 1943.

MEASUREMENTS

Use of dietary supplements and medications during the last seven days was recorded in a face-to-face interview in 2009. Participants were asked to bring all packages of ingested preparations to the study center. Not only vitamin/mineral supplements, but also non-vitamin non-mineral non-herbal supplements and drugs containing vitamins and minerals were coded as DS.

RESULTS

The age-standardized prevalence of DS intake was 54.3% in women and 33.8% in men, respectively. The most commonly supplemented mineral and vitamin, respectively, was magnesium (31.9%) and vitamin D (21.5%) in women and magnesium (18.0%) and vitamin E (12.0%) in men. The highest intakes, compared to the German Dietary Reference Intakes, were reported for biotin, vitamin B6 and B1. Excessive intakes (equal or above the European Tolerable Upper Intake Levels (UL)) were observed especially for magnesium and vitamin E. 20.2% of the women and 32.5% of the men who took magnesium supplements regularly exceeded the UL for magnesium. In case of vitamin E this was true for 8.0% of the women and 13.6% of the men. Determinants of DS use were sex, education, smoking, physical activity, neurological diseases, and stroke.

CONCLUSION

A high proportion of the general population aged 65 years and older in Southern Germany uses DS, especially supplements containing vitamins/minerals. The supplementation of vitamin D can be regarded as favorable in this age group, whereas the excessive intakes of vitamin E might be a cause of concern.

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.

Dietary supplement use and health-related behaviors in a Mediterranean population

OBJECTIVE

To determine predictors and health-related motivation for supplement use.

DESIGN

Population-based, cross-sectional survey. Food intake was determined by a validated food frequency questionnaire that included questions on dietary supplement consumption. Physical activity, smoking status, educational level, self-perceived mental and physical health, and medical information and drug treatment of diabetes, hypertension, and hypercholesterolemia were recorded. Weight and height were measured.

SETTING

Girona, Spain.

PARTICIPANTS

Six thousand three hundred fifty-two men and women aged 35-80 years.

ANALYSIS

Multiple logistic regression analysis to evaluate the association between dietary supplement use and the other variables.

RESULTS

Dietary supplements were consumed by 9.3% of the participants. Positive predictors of supplement use were female sex (odds ratio = 2.44, 95% confidence interval 1.96-3.04), higher educational level (P < .001), and a high adherence to the Mediterranean diet pattern (P < .001) and to the nutrient adequacy score (P = .004). A higher body mass index (P < .001) and the awareness of hypertension (odds ratio = 0.69, 95% confidence interval 0.56-0.87) were negatively associated with supplement use.

CONCLUSIONS AND IMPLICATIONS

The relatively small number of dietary supplement users did not show a clustering of healthy lifestyle habits. Self-perception of mental and physical health and awareness of a cardiometabolic disorder were not motivators for supplement use.

Predictors of dietary supplement use among female health workers in Tehran

BACKGROUND

Despite the lack of evidence on the necessity of dietary supplements to meet nutrients requirements, the majority of people use them all over the world. This study aimed to investigate factors associated with supplement use in women who work in health centers in the city of Tehran.

METHODS

Five hundred sixty three female health workers participated in a cross-sectional study carried out in 2010 in health centers of Tehran. Weight, height, and waist circumference were measured and body mass index was calculated. Data on demographic characteristics, lifestyle, and dietary supplement use were collected by interviewing. The analysis was conducted using univariate and multivariate logistic regression (MLR) in SPSS version 16.

RESULTS

The prevalence of dietary supplement use was 53.8%. In univariate logistic regression model, age, education, husband's education, duration of employment, and tendency for changing weight at the time of the study were statistically significant predictors (P < 0.05). After MLR analysis, education (OR: 1.11, 95% CI: 1.05-1.17) and duration of employment (OR: 1.04, 95% CI: 1.02-1.06) remained significant in the model. Women with higher education and longer duration of employment had more tendency to use nutrient supplements.

CONCLUSION

Our findings showed that education and duration of employment were the most important predictors for taking dietary supplements in this population.

Patterns of dietary supplement use among older men and women in the UK: findings from the Hertfordshire Cohort Study

OBJECTIVES

To determine patterns of supplement use in a UK community-dwelling older population, and to investigate the extent to which supplement user groups differ, in terms of their sociodemographic and lifestyle characteristics, diet and morbidity.

DESIGN

Cross-sectional cohort study.

SETTING

Home interview and clinic visit.

PARTICIPANTS

3217 Hertfordshire Cohort Study participants, aged 59 to 73.

MEASUREMENTS

Information was obtained on the participant's social and medical history by a trained research nurse. Diet over the preceding 3 months was assessed by Food Frequency Questionnaire; compliance with 'healthy' eating recommendations was defined using individual scores for a 'prudent' dietary pattern, identified using principal components analysis. Details of all dietary supplements taken in the preceding 3 months were recorded. Individual supplements were allocated to one of 10 types based on their nutrient composition. Cluster analysis was used to define groups of supplement users.

RESULTS

45.4% of men and 57.5% of women reported taking at least one dietary supplement in the previous 3 month period. There were 5 distinct clusters of supplement users; these were common to men and women. They were labelled according to the principal supplement taken; oils, glucosamine, single vitamins, vitamins and minerals, and herbal products. These groups differed in their social class and prudent diet score, but few other characteristics. With the exception of a difference in diagnosis of diabetes among the women, there were no differences in morbidity between the supplement groups in either men or women.

CONCLUSIONS

Dietary supplement use is high in this population. There are distinct patterns of supplement use, which are related to sociodemographic and lifestyle characteristics including diet, though there were few clear differences in morbidity.

Vitamin C intake from diary recordings and risk of breast cancer in the UK Dietary Cohort Consortium

BACKGROUND/OBJECTIVES

Vitamin C intake has been inversely associated with breast cancer risk in case-control studies, but not in meta-analyses of cohort studies using Food Frequency Questionnaires, which can over-report fruit and vegetable intake, the main source of vitamin C. This is the first study to investigate associations between vitamin C intake and breast cancer risk using food diaries.

SUBJECTS/METHODS

Estimated dietary vitamin C intake was derived from 4-7 day food diaries pooled from five prospective studies in the UK Dietary Cohort Consortium. This nested case-control study of 707 incident breast cancer cases and 2144 matched controls examined breast cancer risk in relation to dietary vitamin C intake using conditional logistic regression adjusting for relevant covariates. Additionally, total vitamin C intake from supplements and diet was analysed in three cohorts.

RESULTS

No evidence of associations was observed between breast cancer risk and vitamin C intake analysed for dietary vitamin C intake (odds ratios (OR)=0.98 per 60 mg/day, 95% confidence interval (CI): 0.88-1.09, P (trend)=0.7), dietary vitamin C density (OR=0.97 per 60 mg/day, 95% CI: 0.87-1.07, P (trend)=0.5 ) or total vitamin C intake (OR=1.01 per 60 mg/day, 95% CI: 0.99-1.03, P (trend)=0.3). Additionally, there was no significant association for post-menopausal women (OR=1.02 per 60 mg/day, 95% CI: 0.99-1.05, P (trend)=0.3).

CONCLUSIONS

This pooled analysis of individual UK women found no evidence of significant associations between breast cancer incidence and dietary or total vitamin C intake derived uniquely from detailed diary recordings.

Comparison of standardised dietary folate intake across ten countries participating in the European Prospective Investigation into Cancer and Nutrition

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.

Intake of micronutrients among Danish adult users and non-users of dietary supplements

Objectives

To evaluate the intake of micronutrients from the diet and from supplements in users and non-users of dietary supplements, respectively, in a representative sample of the Danish adult population. A specific objective was to identify the determinants of supplement use.

Design

A cross-sectional representative national study of the intake of vitamins and minerals from the diet and from dietary supplements.

Method

The Danish National Survey of Dietary Habits and Physical Activity, 2000–2004. Participants (n=4,479; 53% females) aged 18–75 years gave information about the use of dietary supplements in a personal interview. The quantification of the micronutrient contribution from supplements was estimated from a generic supplement constructed from data on household purchases. Nutrient intakes from the diet were obtained from a self-administered 7-day pre-coded dietary record. Median intakes of total nutrients from the diets of users and non-users of supplements were analysed using the Wilcoxon rank-sum test.

Results

Sixty percent of females and 51% of males were users of supplements. With the exception of vitamin D, the intake of micronutrients from the diet was adequate at the group level for all age and gender groups. Among females in the age group 18–49 years, the micronutrient intake from the diet was significantly higher compared with the non-users of dietary supplements. The use of dietary supplements increased with age and with ‘intention to eat healthy.’

Conclusion

Intake of micronutrients from the diet alone was considered adequate for both users and non-users of dietary supplements. Younger females who were supplement users had a more micronutrient-dense diet compared to non-users.

Developing a database of vitamin and mineral supplements (ViMiS) for the Norfolk arm of the European Prospective Investigation into Cancer (EPIC-Norfolk)

OBJECTIVE

Supplements are an important source of micronutrient intake, which, unless taken into account, can misclassify individuals with regard to levels of nutrient exposure. A label-based vitamin and mineral supplements (ViMiS) database was developed to contain manufacturers' information and to enter supplement use by participants in the European Prospective Investigation into Cancer and Nutrition in Norfolk (EPIC-Norfolk). The ViMiS database contains information on all ingredients, broken down into nutrient information in order to be combined with nutrient intake derived from food consumption.

DESIGN

Development of the ViMiS database and cross-sectional analysis of supplement use in a population-based study.

SETTING

Men and women aged 40-79 years from the general population participating in the EPIC-Norfolk study between 1993 and 1997, with data available from 7 d diet diaries (7dDD).

SUBJECTS

A subset of 19 330 participants with available 7dDD and known supplement status.

RESULTS

To date, the ViMiS database includes 2066 supplements, which altogether contain 16 586 ingredients, with a median of eleven nutrient/ingredients per supplement. Forty per cent of the cohort took a supplement, of which cod liver oil was the most common (24·5 %).

CONCLUSIONS

The ViMiS database provides a flexible tool for estimating total nutrient intake. The high prevalence of supplement use in the general population indicates that supplement use needs to be taken into account when examining the relationship of intake of particular nutrients to health outcomes.

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.

Consistency of vitamin and/or mineral supplement use and demographic, lifestyle and health-status predictors: findings from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Heidelberg cohort

Cross-sectional studies suggest that dietary supplement use is associated with favourable demographic and lifestyle factors and certain health conditions. However, factors that affect the consistency of supplement use have not been investigated in prospective cohort studies. The aim of the present study was to seek baseline demographic, lifestyle and health-status predictors of subsequent consistent vitamin and/or mineral supplement use. A total of 8968 men and 10 672 women of the European Prospective Investigation into Cancer and Nutrition (EPIC)-Heidelberg cohort, who answered the supplement-use questions in the baseline survey and two follow-up surveys, were categorised into three groups: consistent, inconsistent and never users. At baseline, 28·5 % of men and 38·6 % of women reported vitamin and/or mineral supplement use. After a median follow-up of 8·5 years, 14·6 % of men and 22·9 % of women were consistent users. During follow-up, 36·0 % of male and 26·6 % of female initial users stopped supplement use, whereas 27·8 % of male and 39·4 % of female initial non-users started supplement use. Women were more likely to be consistent users than men. Older age ( ≥ 50 years), lower BMI ( < 25 kg/m2) and self-reported hyperlipidaemia were common predictors of consistent use for both sexes. Additional predictors included higher educational level for men, and being more physically active and higher lifetime alcohol consumption for women. Consistent users had the highest intake of dairy products, fish, fruits and vegetables, and wine but the lowest intake of total meat. We concluded that supplement use is a fairly unstable behaviour in free-living individuals. Individuals with a favourable lifestyle and healthier diet are more likely to show consistent supplementation.

Dietary intake of the water-soluble vitamins B1, B2, B6, B12 and C in 10 countries in the European Prospective Investigation into Cancer and Nutrition

OBJECTIVES

To describe the intake of vitamins thiamine (B1), riboflavin (B2), B6 (pyridoxine), B12 (cobalamine) and C (ascorbic acid) and their food sources among 27 centres in 10 countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study.

METHODS

Between 1995 and 2000, 36 034 persons aged between 35 and 74 years were administered a standardized 24-h dietary recall using a computerized interview software programme (EPIC-SOFT). Intakes of the four B vitamins and vitamin C were estimated using the standardized EPIC Nutrient Database (ENDB). Mean intakes were adjusted for age and weighted by season and day of recall.

RESULTS

Intake of B vitamins did not vary considerably between centres, except in the UK health-conscious cohort, in which substantially higher intakes of thiamine and lower intakes of vitamin B12 were reported compared with other centres. Overall, meat was the most important contributor to the B vitamins in all centres except in the UK health-conscious group. Vitamin C showed a clear geographical gradient, with higher intakes in the southern centres as compared with the northern ones; this was more pronounced in men than in women. Vegetables and fruits were major contributors to vitamin C in all centres, but juices and potatoes were also important sources in the northern centres.

CONCLUSIONS

This study showed no major differences across centres in the mean intakes of B vitamins (thiamine, riboflavin, B6, B12), whereas a tendency towards a north-south gradient was observed for vitamin C.

Is vitamin C supplementation beneficial? Lessons learned from randomised controlled trials

In contrast to the promised 'antioxidant miracle' of the 1980s, several randomised controlled trials have shown no effect of antioxidant supplements on hard endpoints such as morbidity and mortality. The former over-optimistic attitude has clearly called for a more realistic assessment of the benefit:harm ratio of antioxidant supplements. We have examined the literature on vitamin C intervention with the intention of drawing a conclusion on its possible beneficial or deleterious effect on health and the result is discouraging. One of several important issues is that vitamin C uptake is tightly controlled, resulting in a wide-ranging bioavailability depending on the current vitamin C status. Lack of proper selection criteria dominates the currently available literature. Thus, while supplementation with vitamin C is likely to be without effect for the majority of the Western population due to saturation through their normal diet, there could be a large subpopulation with a potential health problem that remains uninvestigated. The present review discusses the relevance of the available literature on vitamin C supplementation and proposes guidelines for future randomised intervention trials.