Allowing for variations in multivitamin supplement composition improves nutrient intake estimates for epidemiologic studies

Dietary supplements increase the risk of excessive micronutrient intakes in Danish children

PURPOSE

Dietary supplement use is common in Northern Europe. Many dietary supplements contain 100% of nutrient reference values (NRV) of micronutrients. This study investigates the contribution of dietary supplements to micronutrient intake, the prevalence of excess intake of micronutrients, and parental characteristics of dietary supplement use in Danish children.

METHODS

Data on 499 4-10-year-old children from the Danish National Survey of Diet and Physical Activity 2011-2013 were analysed using non-parametric statistics to compare micronutrient intake from the diet and dietary supplements to the reference intake (RI), and to the tolerable Upper Intake Level (UL) for users and non-users of dietary supplements. Furthermore, characteristics of the parents of users and non-users of dietary supplements were examined by logistic regression analysis.

RESULTS

Sixty-four percent of the children were dietary supplement users. Multivitamin-mineral supplements were the most frequently used type of supplement (60%). Children of never-smokers were more likely to use supplements than children of smokers. Users had significantly higher total intakes of 15 micronutrients compared to non-users. Intakes of vitamin A, zinc, and iodine from the diet alone exceeded ULs in 12-30% of the children. Use of dietary supplements gave rise to 21-73% of children in exceedance of the aforementioned three ULs as well as the UL for iron (6-45%).

CONCLUSION

Dietary supplement use was common among 4-10-year-old Danish children and resulted in a considerable proportion of users exceeding the ULs for vitamin A, zinc, iodine, and iron. The long-term health consequences of exceeding these ULs for children are unknown.

Maternal preconception circulating blood biomarker mixtures, child behavioural symptom scores and the potential mediating role of neonatal brain microstructure: the S-PRESTO cohort

Human brain development starts in the embryonic period. Maternal preconception nutrition and nutrient availability to the embryo may influence brain development at this critical period following conception and early cellular differentiation, thereby affecting offspring neurodevelopmental and behavioural disorder risk. However, studying this is challenging due to difficulties in characterizing preconception nutritional status and few studies have objective neurodevelopmental imaging measures in children. We investigated the associations of maternal preconception circulating blood nutrient-related biomarker mixtures (~15 weeks before conception) with child behavioural symptoms (Child Behaviour Checklist (CBCL), aged 3 years) within the Singapore Preconception Study of Long-Term Maternal and Child Outcomes (S-PRESTO) study. The CBCL preschool form evaluates child behaviours based on syndrome scales and Diagnostic and Statistical Manual of Mental Disorders (DSM) oriented scales. These scales consist of internalizing problems, externalizing problems, anxiety problems, pervasive developmental problems, oppositional defiant, etc. We applied data-driven clustering and a method for modelling mixtures (Bayesian kernel machine regression, BKMR) to account for complex, non-linear dependencies between 67 biomarkers. We used effect decomposition analyses to explore the potential mediating role of neonatal (week 1) brain microstructure, specifically orientation dispersion indices (ODI) of 49 cortical and subcortical grey matter regions. We found that higher levels of a nutrient cluster including thiamine, thiamine monophosphate (TMP), pyridoxal phosphate, pyridoxic acid, and pyridoxal were associated with a higher CBCL score for internalizing problems (posterior inclusion probability (PIP) = 0.768). Specifically, thiamine independently influenced CBCL (Conditional PIP = 0.775). Higher maternal preconception thiamine level was also associated with a lower right subthalamic nucleus ODI (P-value = 0.01) while a lower right subthalamic nucleus ODI was associated with higher CBCL scores for multiple domains (P-value < 0.05). One potential mechanism is the suboptimal metabolism of free thiamine to active vitamin B1, but additional follow-up and replication studies in other cohorts are needed.

A Dietary Supplement Frequency Questionnaire Correctly Ranks Nutrient Intakes in US Older Adults When Compared to a Comprehensive Dietary Supplement Inventory

BACKGROUND

Dietary supplements are commonly taken by adults in the United States and can contribute substantially to daily nutrient intakes. Short supplement-use questionnaires are often used in dietary surveys, but their accuracy has not been well studied.

OBJECTIVES

The primary objective was to evaluate the accuracy of a short, self-administered supplement frequency questionnaire (SFQ) relative to a comprehensive 1-y inventory of supplement use. A secondary objective was to compare SFQ responses for participants in the intensive measurement study to those from a control group to investigate a possible research participation effect.

METHODS

The Supplement Reporting study enrolled 1029 older adults in 2005-2006, with a mean age of 67.8 y, who participated in the Multiethnic Cohort and reported regular use of dietary supplements. Of these, 375 were interviewed quarterly to collect detailed information on types and amounts of dietary supplements used, while 654 served as the control group. All participants completed 2 SFQs, 1 y apart.

RESULTS

Agreement between the 2 instruments in use at least weekly ranged from 88% to 97% for 15 of 16 supplement types, with a lower agreement of 74% for vitamin D. The correlations of nutrient intakes from supplements between the 2 instruments were high, ranging from 0.48 to 0.75, except for iron (r = 0.29). However, mean nutrient intakes as reported on the SFQ were higher than intakes from the inventory for most nutrients, sometimes twice as high. Nutrient intakes based on the SFQ were similar for the inventory and control groups, at both baseline and the end of the study.

CONCLUSIONS

A self-administered short SFQ can be used in large surveys to identify participants who use 16 categories of dietary supplements at least once a week and can correctly rank participant intakes of nutrients. However, the SFQ does not accurately estimate absolute levels of nutrient intakes from supplements.

Small Increments in Vitamin D Intake by Irish Adults over a Decade Show That Strategic Initiatives to Fortify the Food Supply Are Needed

BACKGROUND

Food fortification could be an effective method of increasing vitamin D intakes and preventing deficiency with minimal risk of excessive dosing.

OBJECTIVE

Secular trends in vitamin D intakes were examined over a 10-y period.

METHODS

We compared vitamin D intakes among 18- to 64-y-old adults from the base diet, fortified foods, and supplements in 2 nationally representative dietary surveys in 1999 and 2009 implemented using the same methodology.

RESULTS

There was a slight increase in the median (IQR) intake of vitamin D from 2.9 (3.2) to 3.5 (3.7) μg/d (mean ± SD, 4.3 ± 4.0 to 5.0 ± 6.4 μg). The median (IQR) intake from the base diet was 2.3 (1.6) μg/d in 1999 and 2.1 (1.8) μg/d in 2009. In vitamin D supplement users, median (IQR) intakes were 7.6 (6.7) and 8.7 (7.2) μg/d and the prevalence of inadequacy decreased from 67% to 57% in 2009. Although the consumption of vitamin D-containing supplements was similar in the 2 surveys (17% and 16%), the use of calcium-vitamin D supplements increased from 3% to 10% among women aged 50-64 y. The prevalence of fortified food consumption was also similar at 60%, and median (IQR) vitamin D intakes in consumers were 2.9 (2.2) and 3.7 (2.9) μg/d in 1999 and 2009, respectively. Mathematical modeling of food fortification using modified vitamin D composition data showed that there is potential to increase vitamin D intakes at the lower end of the distribution, without increasing the risk of exceeding the Tolerable Upper Intake Level.

CONCLUSIONS

We report small increases in vitamin D intakes among Irish adults over a decade of focus on vitamin D and in the context of a voluntary fortification policy. Strategic management of vitamin D in the food supply is required to yield measurable benefits.

An assessment of vitamin supplements in the Indian market

We aimed to study the composition and availability of various vitamin preparations in the Indian market, data about which was collected from an annual Drug Compendium. The preparations were assessed for total number, different formulations, constituents and amount of each constituent present in the formulation. A large number of vitamin supplements are available in the Indian market. It includes single-ingredient products and various combinations of vitamins, minerals, and other constituents. Among single products, the maximum number was that of vitamin D3 (n=150). Most of the supplements are available as combinations (76.49%), with vitamin-minerals combinations constituting the maximum number. In a large number of products, amount of the vitamins was not specified. The most common formulation for oral administration was capsules (34.1%). In our research, majority of the supplements contained nutrient amounts higher than the recommended intakes recommended dietary allowance. Unsupervised intake of vitamins can pose a serious health risk in the susceptible population. The composition and amount of each constituent in the dietary supplement should be detailed and properly labelled for each preparation. Availability of a large number of preparations with unknown composition as ‘over the counter’ agents requires a serious review of the legal provisions in India for drug manufacturing and marketing. There is a need for proper guidelines and regulations for the manufacturing, labelling and marketing of dietary supplements in India. Strict enforcement of such provisions is essential to safeguard the health of the population at large.

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.

Multivitamin use and the risk of mortality and cancer incidence: the multiethnic cohort study

Although multivitamin/mineral supplements are commonly used in the United States, the efficacy of these supplements in preventing chronic disease or premature death is unclear. To assess the relation of multivitamin use with mortality and cancer, the authors prospectively examined these associations among 182,099 participants enrolled in the Multiethnic Cohort Study between 1993 and 1996 in Hawaii and California. During an average 11 years of follow-up, 28,851 deaths were identified. In Cox proportional hazards models controlling for tobacco use and other potential confounders, no associations were found between multivitamin use and mortality from all causes (for users vs. nonusers: hazard ratio = 1.07, 95% confidence interval: 0.96, 1.19 for men; hazard ratio = 0.96, 95% confidence interval: 0.85, 1.09 for women), cardiovascular diseases, or cancer. The findings did not vary across subgroups by ethnicity, age, body mass index, preexisting illness, single vitamin/mineral supplement use, hormone replacement therapy use, and smoking status. There also was no evidence indicating that multivitamin use was associated with risk of cancer, overall or at major sites, such as lung, colorectum, prostate, and breast. In conclusion, there was no clear decrease or increase in mortality from all causes, cardiovascular disease, or cancer and in morbidity from overall or major cancers among multivitamin supplement users.

Multivitamin supplement use and risk of invasive breast cancer

OBJECTIVE

Multivitamin supplements are used by nearly half of middle-aged women in the USA. Despite this high prevalence of multivitamin use, little is known about the effects of multivitamins on health outcomes, including cancer risk. Our main objective was to determine the association between multivitamin use and the risk of breast cancer in women.

DESIGN

We conducted a population-based case-control study among 2968 incident breast cancer cases (aged 20-69 years), diagnosed between 2004 and 2007, and 2982 control women from Wisconsin, USA. All participants completed a structured telephone interview which ascertained supplement use prior to diagnosis, demographics and risk factor information. Odds ratios and 95 % confidence intervals were calculated using multivariable logistic regression.

RESULTS

Compared with never users of multivitamins, the OR for breast cancer was 1.02 (95 % CI 0.87, 1.19) for current users and 0.99 (95 % CI 0.74, 1.33) for former users. Further, neither duration of use (for > or =10 years: OR = 1.13, 95 % CI 0.93, 1.38, P for trend = 0.25) nor frequency (>7 times/week: OR = 1.00, 95 % CI 0.77, 1.28, P for trend = 0.97) was related to risk in current users. Stratification by menopausal status, family history of breast cancer, age, alcohol, tumour staging and postmenopausal hormone use did not significantly modify the association between multivitamin use and breast cancer.

CONCLUSIONS

The current study found no association between multivitamin supplement use and breast cancer risk in women.

Development of a supplement composition database for the SURE Study

The Supplement Reporting (SURE) study is one of the first to systematically examine the accuracy of collection of dietary supplement use data for population-based studies of diet. In 2005-2007, the SURE study collected data from 444 participants in Hawaii and Los Angeles. Several methods of collecting data were compared, including an inventory of supplements, a recall, a daily diary, and a one-page supplement frequency questionnaire. Considerable effort was put into developing an extensive supplement composition database. To quantify intakes, we extended the existing supplement composition table (SCT) used at the Cancer Research Center of Hawaii. The original SCT contained default codes for multivitamin/multimineral products to be used when insufficient detail was available to assign an existing code. However, the default concept needed to be expanded for the SURE study to include additional multivitamin/multimineral default codes, as well as single nutrients and other components. Approximately 1800 new codes were created, including 211 new default codes. Roughly 130 nutrients and 870 other components were included in the SCT at the conclusion of the study. To accurately quantify intakes from supplements, it is crucial to maintain a comprehensive supplement composition database. Future improvements to our SCT include incorporation of analytic values from the US Department of Agriculture to replace composition data taken from supplement labels.

Dietary supplement use among elderly, long-term cancer survivors

INTRODUCTION

The purpose of the present study was to assess dietary supplement use and its association with micronutrient intakes and diet quality among older (>or=65 years), long-term survivors (>or=5 years post-diagnosis) of female breast, prostate, and colorectal cancer.

METHODS

The sample included 753 survivors who participated in telephone screening interviews to determine eligibility for a randomized diet and physical activity intervention trial entitled RENEW: Reach-out to ENhancE Wellness in Older Cancer Survivors. Telephone surveys included two 24-hour dietary recalls and items regarding supplement use (type, dose, and duration). Nutrient intakes were compared to Dietary Reference Intakes (DRIs). Diet quality was assessed using the revised Healthy Eating Index (HEI). Descriptive statistics and multivariate logistic regression were used in this cross-sectional study.

RESULTS

A majority of survivors (74%) reported taking supplements, with multivitamins (60%), calcium/vitamin D (37%), and antioxidants (30%) as the most prevalent. Overall proportions of the total sample with dietary intakes below Estimated Average Requirements (EARs) were substantial, although supplement users had more favorable mean HEI scores (P < 0.01) and nutrient intakes for 12 of the 13 vitamins and minerals investigated (P values < 0.05). Supplement use was positively associated with older age (>or=70 years) (odds ratio (OR)=1.70; 95% confidence interval (95% CI)=1.17, 2.46) and female gender (OR=1.49; 95% CI=1.04, 2.13), and negatively associated with current smoking (OR=0.40, 95% CI=0.21, 0.76). Individuals scoring higher on the Total Fruit (OR=1.12, 95% CI=1.01, 1.23), Whole Grain (OR=1.14, 95% CI=1.04, 1.25), and Oil (OR=1.10, 95% CI=1.01, 1.11) components of the HEI were significantly more likely to take supplements, while those scoring higher on the Meat and Beans category (OR=0.81, 95% CI=0.71, 0.93) were significantly less likely to take supplements. Compared to those with less than a high school education, survivors with a professional or graduate degree were significantly more likely to use supplements (OR=2.18, 95% CI=1.13, 4.23).

DISCUSSIONS/CONCLUSIONS

Demographic, disease, and health-related correlates of supplement use follow similar trends observed in the general population as well as previous reports from other cancer survivor populations. Supplement use may reduce the prevalence of nutrient inadequacies in this population, though survivors who use supplements are the least likely to need them.

IMPLICATIONS FOR CANCER SURVIVORS

Supplement use may be an effective means for many survivors to achieve adequate nutrient intakes; however, open communication between healthcare providers and survivors is needed to ensure potential concerns are addressed as supplement use may not always be beneficial.

Dietary supplement use and risk of neoplastic progression in esophageal adenocarcinoma: a prospective study

The incidence of esophageal adenocarcinoma (EA) and its precursor condition, Barrett's esophagus, has risen rapidly in the United States for reasons that are not fully understood. Therefore, we evaluated the association between use of supplemental vitamins and minerals and risk of neoplastic progression of Barrett's esophagus and EA. The Seattle Barrett's Esophagus Program is a prospective study based on 339 men and women with histologically confirmed Barrett's esophagus. Participants underwent baseline and periodic follow-up exams, which included endoscopy and self-administered questionnaires on diet, supplement use, and lifestyle characteristics. Use of multivitamins and 4 individual supplements was calculated using time-weighted averages of reported use over the observational period. Cox proportional-hazards models were used to calculate hazard ratios (HR) for each endpoint: EA, tetraploidy, and aneuploidy. During a mean follow-up of 5 yr, there were 37 cases of EA, 42 cases of tetraploidy, and 34 cases of aneuploidy. After controlling for multiple covariates including diet, nonsteroidal anti-inflammatory drug use, obesity, and smoking, participants who took 1 or more multivitamin pills/day had a significantly decreased risk of tetraploidy [HR = 0.19; 95% confidence interval (CI) = 0.08-0.47) and EA (HR = 0.38; 95% CI = 0.15-0.99] compared to those not taking multivitamins. Significant inverse associations were also observed between risk of EA and supplemental vitamin C (> or = 250 mg vs. none: HR = 0.25; 95% CI = 0.11-0.58) and vitamin E (> or = 180 mg vs. none: HR = 0.25; 95% CI = 0.10-0.60). In this cohort study, use of multivitamins and single antioxidant supplements was associated with a significantly reduced risk of EA and markers of neoplastic progression among individuals with Barrett's esophagus.

Nutrient intake from multivitamin/mineral supplements is similar among users from five ethnic groups: the Multiethnic Cohort Study

A multivitamin/mineral supplement is the most widely used type of dietary supplement among American adults. Therefore, accurate assessment of intake from this supplement is crucial when studying diet and chronic diseases. From 1999 to 2001, the Multiethnic Cohort Study collected detailed information on multivitamin/mineral use among five ethnic groups: African Americans, Native Hawaiians, Japanese Americans, Latinos, and whites. Daily nutrient intakes from multivitamin/minerals were calculated using the nutrient composition specified on the product label. For reported supplements with insufficient detail to match to a specific product, default nutrient profiles were assigned. Multivitamin/mineral use was reported by 50% of the participants (38% for Native Hawaiians to 57% for whites). Default profiles were assigned for 38% of users. The median daily nutrient intakes from multivitamin/minerals among users (n=75,865) were well above the Recommended Daily Allowance or Adequate Intake for vitamins A, B-6, B-12, and E, thiamin, riboflavin, niacin, pantothenic acid, folate, and zinc. Although nutrient intakes from multivitamin/minerals varied widely among individuals, there was no substantial difference in the median intake across ethnic groups. To accurately estimate nutrient intakes from multivitamin/minerals, detailed information on the product consumed should be collected. When detailed information is not available, the same default nutrient profiles can be used when estimating intakes for these five ethnic groups.

A computer-based approach for assessing dietary supplement use in conjunction with dietary recalls

In response to the need to assess both food and supplemental sources of nutrients, we have expanded the capabilities of Nutrition Data System for Research (NDSR) software to allow for assessing dietary supplement use. A Dietary Supplement Assessment Module allows for the automated collection and coding of dietary supplement use. The module is designed for use in conjunction with the software's 24-hour dietary recall features. The medication inventory method, commonly used in pharmaceutical research, served as the basis for the module's assessment approach. In adapting this approach for use in our software we designed a tiered structure that involves first screening for use of dietary supplements, then collecting product detail (e.g. full name of product, number of times taken, etc.), and finally reviewing the information with the participant. Preliminary results from a demonstration study being conducted to evaluate the Module indicate the assessment approach is acceptable to both participants and interviewers. Collecting dietary supplement use information significantly increases interview time, especially for those using multiple products. A validation study is needed to determine whether the new method results in accurate estimation of nutrient intake from supplemental sources.

Multivitamin and multimineral dietary supplements: definitions, characterization, bioavailability, and drug interactions

Although multivitamins, multiminerals, and similar terms (eg, multis or multiples) are commonly used, they have no standard scientific, regulatory, or marketplace definitions. Thus, multivitamins-multiminerals refers to products with widely varied compositions and characteristics. Multivitamin-multimineral composition databases use label values as surrogates for analyzed values. However, actual vitamin and mineral amounts often deviate from label values. Vitamin and mineral bioavailability for dietary supplements also lacks a standard scientific and regulatory definition and validated in vitro and animal models that accurately reflect human bioavailabilities. Systematic information on the bioavailability and bioequivalence of vitamins and minerals in marketed products and on potential drug interactions is scarce. Because of limited information on product characteristics, our ability to directly compare results across studies, estimate changes in usage patterns or intakes over time, and generalize from published results to marketed products is problematic.