Characteristics of vitamin and mineral supplement products in the United States

The inverse association between serum 25-hydroxyvitamin D and mortality may be modified by vitamin A status and use of vitamin A supplements

BACKGROUND

Low serum 25-hydroxyvitamin D [25(OH)D] levels have been associated with higher risk of many diseases that affect mortality, including cardiovascular disease (CVD) and cancer. The inverse association between serum 25(OH)D and mortality may be modified by excess circulating vitamin A, due to interactions of vitamin A at the level of the vitamin D nuclear receptor. In this prospective cohort study, we investigated whether the association of 25(OH)D with all-cause, cancer, and CVD mortality was modified by circulating vitamin A or preformed vitamin A intake from supplements.

METHODS

We analyzed 15,998 adults in the Third National Health and Nutrition Examination Survey (NHANES III), 1988-1994. Mortality data for all-cause (n = 3890), cancer (n = 844), and CVD mortality (n = 1715) were assessed through December 2006. Serum 25(OH)D was measured using a radioimmunoassay kit, vitamin A biomarkers were measured by HPLC, and information on supplement use was obtained by self-report. Multivariable hazard ratios (HRs) and corresponding 95% confidence intervals (CI) were estimated by proportional hazards regression.

RESULTS

Serum 25(OH)D was significantly inversely associated with all-cause mortality (HR 0.93, 95% CI 0.89, 0.97, per 10 ng/mL increase) and also with CVD mortality and mortality due to non-cancer/non-cardiovascular causes, but not with cancer mortality. The observed inverse associations remained statistically significant only among participants with serum retinyl esters <7.0 μg/dL. High intake (>5000 IU/day) of preformed vitamin A from supplements attenuated the inverse association of 25(OH)D with overall mortality. The observed interactions were not statistically significant.

CONCLUSIONS

25(OH)D was inversely associated with overall mortality, CVD mortality, and mortality due to non-cancer/non-CVD causes, but not with cancer mortality. A possible interaction between vitamin A exposure and 25(OH)D concentration appears to be associated with an attenuation of the inverse association between risk of death and quartile of 25(OH)D concentration.

Vitamin D and calcium-sensing receptor polymorphisms differentially associate with resting energy expenditure in peripubertal children

Given that calcium metabolism is influenced by genes and is tightly linked to energy-utilizing pathways, this study evaluated the association of single nucleotide polymorphisms (SNPs) in the vitamin D receptor (VDR) and calcium-sensing receptor (CASR) with resting energy expenditure (REE). In 273 boys and girls, 7-12 years of age, cross-sectional REE was measured via indirect calorimetry, body composition by DXA, and dietary measures by 24-h recall. SNPs for VDR Cdx-2 (rs11568820) and CASR A986S (rs1801725) were genotyped using the Illumina Golden Gate assay. Multiple linear regression models were used to determine the association between SNPs and REE. African American carriers of the 'A' VDR Cdx2 allele had increased levels of REE in the overall sample, and this association was apparent among participants with an adiposity level of <25 % and 30 % body fat in males and females, respectively. For CASR, an association between carriers of the 'A' allele and REE was observed only in those in the upper median of calcium intake. VDR and CASR variants are associated with REE in children and are influenced by levels of calcium intake and adiposity. Our results bring awareness to mechanisms underlying the regulation of REE and biological and dietary influential factors.

Serum 25-hydroxyvitamin D, vitamin A, and lung cancer mortality in the US population: a potential nutrient-nutrient interaction

OBJECTIVE

Excess vitamin A may interrupt vitamin D-mediated transcription of target genes. This study investigated whether serum 25-hydroxyvitamin D [25(OH)D] concentrations were associated with lung cancer mortality, and whether this association varied by excess circulating vitamin A and vitamin A/β-carotene supplement use.

METHOD

We analyzed 16,693 men and women in the Third National Health and Nutrition Examination Survey (NHANES III), 1988-1994. Lung cancer mortality (n = 258, 104 were former smokers and 23 were never smokers) were identified through National Death Index as of 2006. Serum 25(OH)D was measured by a radioimmunoassay. Vitamin A biomarkers including serum retinol, β-carotene, and retinyl esters were measured by HPLC. Supplement use for the past month was obtained by self-report. Multivariate-adjusted hazard ratios (HR) were estimated by Cox proportional hazard models.

RESULTS

There was no association of serum 25(OH)D with overall lung cancer mortality. Among nonsmokers, ≥44 vs. <44 nmol/L of serum 25(OH)D was associated with a decreased risk (HR = 0.53, 95 % CI = 0.31-0.92, former/never smokers and HR = 0.31, 95 % CI = 0.13-0.77, distant-former [quit ≥20 years]/never smokers). The associations were not observed among participants with excess circulating vitamin A (serum retinyl esters ≥7.0 μg/dL or the ratio of retinyl esters to retinol ≥0.08) or vitamin A/β-carotene supplement users. However, statistical evidence to support effect modification of vitamin A was less clear.

CONCLUSIONS

Serum 25(OH)D concentrations were inversely associated with lung cancer mortality in nonsmokers. The beneficial association was diminished among those with excess circulating vitamin A or vitamin A/β-carotene supplement users.

Methods of assessment of iodine status in humans: a systematic review

BACKGROUND

Biomarkers of iodine status are required to study iodine deficiency disorders in different parts of the world and to evaluate the effects of fortification strategies.

OBJECTIVE

The objective was to assess the usefulness of biomarkers of iodine status in humans by systematically reviewing intervention studies that altered iodine status.

DESIGN

We performed a structured search for iodine intervention studies on Ovid MEDLINE, EMBASE (Ovid), and the Cochrane Library. Studies were assessed for inclusion and validity, with independent duplication. A random-effects meta-analysis was performed.

RESULTS

Twenty-one intervention studies (12 randomized controlled trials, 3 controlled clinical trials, and 6 before-after studies) were included in the review. Urinary iodine (in children and adolescents and in those with low and moderate baseline iodine status), thyroglobulin (in children and adolescents but not in pregnant and lactating women), serum thyroxine (in children and adolescents, adults, women, and those with moderate baseline thyroxine status but not in pregnant and lactating women), and serum thyroid-stimulating hormone (in pregnant and lactating women but not in children and adolescents or those at moderate baseline status), but not triiodothyronine, proved to be useful biomarkers of iodine status.

CONCLUSIONS

Despite the high risk of bias of many of the included studies, the results suggested that urinary iodine, thyroglobin, serum thyroxine, and thyroid-stimulating hormone are useful biomarkers of iodine status, at least in some groups. High-quality controlled studies measuring relevant long-term outcomes are needed to address which biomarker is the most appropriate for assessing iodine intake in some population groups and settings.

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.

Dietary supplement use by community-living population in Japan: data from the National Institute for Longevity Sciences Longitudinal Study of Aging (NILS-LSA)

BACKGROUND

There are few studies about dietary supplement use and nutrient intake from these products in Japan. The purpose of this study was to clarify (1) the prevalence of dietary supplement use, (2) the characteristics of dietary supplement users, (3) nutrient intake from dietary supplements, and (4) the existence of dietary supplement users who took excessive nutrients from these products.

METHODS

To collect the information on dietary supplement use in the previous year and nutrient intake from these products, we conducted a self-administered dietary supplement frequency questionnaire. The subjects were 2,259 people aged 40-82 years. Dietary supplements were grouped into 8 major categories. A dietary supplement database was developed to estimate nutrient intake from these products. Excess users were defined as people who consumed more nutrient than the tolerable upper intake level of the Dietary Reference Intakes for Japanese.

RESULTS

In the previous year, 55 % of males and 61 % of females consumed dietary supplements. Dietary supplement use was especially prevalent in females, subjects who felt unhealthy, and subjects who were more careful of maintaining an appropriate weight, though the association was affected by the frequency of dietary supplement use. The most common dietary supplements were drink type in males and vitamins in females. Some nutrient values obtained from dietary supplements were higher than those from food. Excess users were found for intake of vitamin A, B₆, K, niacin, iron, and magnesium.

CONCLUSIONS

It is important to clarify dietary supplement use and to estimate nutrient intake from these products.

Iodine supplementation of pregnant women in Europe: a review and recommendations

OBJECTIVE

Nearly two-thirds of the population of Western and Central Europe live in countries that are iodine deficient. Damage to reproductive function and to the development of the fetus and newborn is the most important consequence of iodine deficiency. The objective of this review was to examine the iodine status of pregnant women in Europe and the potential need for iodine supplementation.

DESIGN

A MEDLINE/PubMed search and compilation of all published studies since 1990 of iodine nutrition and iodine supplementation of pregnant women in Europe, as well as an Internet-based search and review on availability and legislation of iodine supplements in the European Union.

RESULTS

Although the data suggest most women in Europe are iodine deficient during pregnancy, less than 50% receive supplementation with iodine. Mild-to-moderate iodine deficiency during pregnancy adversely affects thyroid function of the mother and newborn and mental development of the offspring and these adverse effects can be prevented or minimized by supplementation. There are no published data on the effect of iodine supplementation on long-term maternal and child outcomes. The iodine content of prenatal supplements in Europe varies widely; many commonly used products contain no iodine. The European Union is developing legislation to establish permissible levels for iodine in food supplements.

CONCLUSIONS

In most European countries, pregnant women and women planning a pregnancy should receive an iodine-containing supplement ( approximately 150 microg/day). Kelp and seaweed-based products, because of unacceptable variability in their iodine content, should be avoided. Prenatal supplement manufacturers should be encouraged to include adequate iodine in their products. Professional organizations should influence evolving EU legislation to ensure optimal doses for iodine in prenatal vitamin-mineral supplements.

SPONSORSHIP

International Council for Control of Iodine Deficiency Disorders.

Antioxidant supplement use in Women's Health Initiative participants

BACKGROUND

Although antioxidant supplements are widely available and commonly used in the United States, there is a lack of detailed information on their use, including types of supplements used, doses, duration of use, and changes in use over time.

METHODS

Antioxidant supplement use was assessed in participants in the Clinical Trial (n = 68,133) and Observational Study (n = 93,676) of the Women's Health Initiative. In-person interviews and a computerized inventory procedure were used to collect data on supplement use during baseline clinic visits from 1993 through 1998.

RESULTS

Antioxidant supplements were widely consumed. For example, 55.5% of participants reported taking supplemental vitamin C in some form. Supplement use was positively associated with age, education, and physical activity. Most antioxidants were consumed through multivitamins. However, high doses were commonly consumed from single supplements, with 43.9% using single vitamin C supplements taking >500 mg and 86.1% using single vitamin E supplements taking >200 IU daily. Except for beta-carotene, there were increases in the use of all supplements from 1993 to 1998.

CONCLUSIONS

This report demonstrates the feasibility of collecting comprehensive dietary supplement use data in large studies. These data may aid in the design of supplement use questionnaires, which could help to prevent misclassification error in epidemiologic studies of diet and disease.

Vitamin B6 therapy during childbearing years: cause for caution?

Vitamin B6, or pyridoxine, is either prescribed or recommended in large doses for a variety of ailments. These ailments include morning sickness and premenstrual syndrome, despite the fact that the effect of large doses of vitamin B6 on developing human fetuses is currently unknown. Both clinical reports and recent experimental evidence indicate, however, that large doses of vitamin B6 can have adverse affects on proprioceptive neuron function, and these deficits may be permanent if caused during development. This evidence suggests that ingestion of large quantities of vitamin B6 should be viewed with caution by pregnant women and women of childbearing potential.

Do adolescent vitamin-mineral supplement users have better nutrient intakes than nonusers? Observations from the CATCH tracking study

OBJECTIVE

Describe whether users of vitamin-mineral supplements differed from nonusers in micronutrient intakes or in nutrition awareness.

DESIGN

Cross-sectional, observational study.

SUBJECTS

One thousand five hundred thirty-two students now in grade 8, who participated in the Third Child and Adolescent Trial for Cardiovascular Health tracking study and who also provided a single 24-hour dietary recall.

STATISTICAL ANALYSES PERFORMED

Mixed-model analysis of covariance was used to ascertain if supplement users had higher vitamin and mineral intakes from food sources, and to examine if supplement users had better nutrition awareness than nonusers.

RESULTS

The 24-hour recall showed that 17.6% of the students reported using vitamin-mineral supplements. Users reported a mean of 1.4 supplements, of which 47% were multivitamin or multimineral preparations, 37% were single nutrients, and 16% were combinations. White persons and residents of Minnesota and California were more likely to be supplement users. Users had higher micronutrient intakes from food sources for 16 of the 20 nutrients studied after adjusting for gender, race/ethnicity, site, treatment condition, and within-school variability. Users had higher scores on a health behavior survey for food choice and slightly but not significantly higher nutrition knowledge scores.

CONCLUSIONS

Vitamin-mineral supplement use is prevalent among eighth-grade students. Users have higher nutrient intakes from foods, higher total intakes for several micronutrients, higher nutrition awareness, and differ in their demographic characteristics from nonusers.

Regulation of hepatic vitamin A storage in a rat model of controlled vitamin A status during aging

It is currently unknown whether the capacity of the liver to esterify and store vitamin A (VA) changes as a function of long-term VA intake or age. The objective of this study was to investigate whether age and/or VA status are factors for the hepatic expression of cellular retinol-binding protein (CRBP), the esterification of retinol by lecithin:retinol acyltransferase (LRAT) and the accumulation of VA and lipids in liver. Two factors, VA intake and age, were studied in a 3x3 design. Diets denoted as VA-marginal, control and supplemented contained 0.35, 4 and 25 mg retinol equivalents/kg diet, respectively; male Lewis rats were fed these diets from weaning until the ages of 2-3 mo (young), 8-10 mo (middle-aged) and 18-20 mo (old) (n = 6/group. Liver CRBP mRNA differed (two-way ANOVA) with dietary VA (P<0.0001) and age (P<0.05). Hepatic LRAT activity increased with dietary VA (P<0.0001). Age was not a factor (P = 0.47) although there was an interaction of age and dietary VA (P<0.0001). Hepatic LRAT activity was correlated (r = 0.633, P<0.0001) with plasma retinol at physiologic concentrations. In VA-supplemented rats of all ages, the plasma molar ratio of total retinol:retinol-binding protein (RBP) exceeded 1, and liver VA and total lipid concentrations were elevated. However, tests of liver function had previously been shown to be within normal values. Thus, the capacity of the liver for retinol esterification by LRAT was not diminished by age or the accumulation of VA and other lipids. We conclude the following: 1) hepatic LRAT activity is regulated across a broad, physiologic range of dietary VA; 2) LRAT activity is regulated throughout life; and 3) the capacity for hepatic VA storage is high throughout life.

Evaluation of a simplified vitamin supplement inventory developed for the Women's Health Initiative

OBJECTIVE

To evaluate the accuracy of a simplified inventory procedure for assessing nutrient intake from vitamin and mineral supplements.

DESIGN

Participants brought their supplements to a clinic. An interviewer conducted the supplement inventory procedure, which consisted of recording data on the type of multiple vitamin and single supplements used. For the multiple vitamins, the interviewer recorded the exact dose for a subset of nutrients (vitamin C, calcium, selenium). For other nutrients, we imputed the dose in multiple vitamins. The dose of all single supplements was recorded. Labels of the supplements were photocopied and we transcribed the exact nutrient label data for the criterion measure. Spearman correlation coefficients were used to assess precision of nutrient intakes from the simplified inventory compared to the criterion measure.

SETTING/SUBJECTS

Data are from 104 adult vitamin supplement users in Washington state.

RESULTS

Correlation coefficients between nutrient intake estimated from the simplified inventory compared to the criterion measure were high (0.8-1.0) for those nutrients (vitamin C, calcium, selenium) for which the interviewer recorded the exact dose contained in multiple vitamins. However, for nutrients for which imputations were made regarding dose in multiple vitamins, correlation coefficients ranged from good (0.8 for vitamin E) to poor (0.3 for iron).

CONCLUSIONS

The simplified inventory is rapid (4-5 min) and practical for large-scale studies. The precision of nutrient estimates using this procedure was variable, although excellent for the subset of nutrients for which the dose was recorded exactly. This study illustrates many of the challenges of collecting high quality supplement data.

Estimated folate intakes: data updated to reflect food fortification, increased bioavailability, and dietary supplement use

BACKGROUND

There is a critical need to estimate dietary folate intakes for nutrition monitoring and food safety evaluations, but available intake data are seriously limited by several factors.

OBJECTIVE

Our objective was to update 2 national food consumption surveys to reflect folate intakes as a result of the recently initiated food fortification program and to correct folate intakes for the apparently higher bioavailability of synthetic folic acid (SFA; ie, folate added to foods or from dietary supplements) than of naturally occurring folate so as to express intakes as dietary folate equivalents.

DESIGN

It was not possible to chemically analyze foods, so adjustments were made to food-composition data by using information about food ingredients and characteristics. Total folate intakes were estimated for several sex and age groups by using the modified data coupled with dietary supplement use.

RESULTS

Within the limitations of the data, our findings suggested that 67-95% of the population met or surpassed the new estimated average requirement, depending on the sex and age group and survey. Nonetheless, some subgroups had estimated intakes below these standards. Estimated SFA intakes suggested that approximately 15-25% of children aged 1-8 y, depending on the survey, had intakes above the newly established tolerable upper intake level. We estimated that 68-87% of females of childbearing age had SFA intakes below the recommended intake of 400 microgram/d, depending on the age group and survey.

CONCLUSION

There is a need to explore ways to improve folate intakes in targeted subgroups, including females of childbearing age, while not putting other population groups at risk of excessive intakes.

Underreporting the use of dietary supplements and nonprescription medications among patients undergoing a periodic health examination

OBJECTIVE

To compare the use of dietary supplements and nonprescription medications as reported on a written medical questionnaire with use reported during a structured interview.

DESIGN

We conducted a prospective study of 200 subjects randomly selected among patients undergoing a periodic health examination in two divisions of the Department of Internal Medicine at Mayo Clinic Rochester--100 patients from a national cohort of executives and 100 community patients.

MATERIAL AND METHODS

Written information on self-reported use of supplements and nonprescription medications was obtained as part of a comprehensive medical questionnaire. Subjects were then interviewed and asked about the use of supplements and nonprescription medications. In addition, the reason for using supplements was elicited and recorded.

RESULTS

The prevalence of use of dietary supplements was 30.5% by written self-report in comparison with 61.0% reported during the structured interview. The results were consistent between executive and community patients. In response to questions about taking nonprescription medications, 24.5% of patients reported such use on the medical questionnaire in comparison with 42.5% when interviewed. The most common dietary supplements taken were multivitamins (41.5%), followed by vitamin E (24.0%) and vitamin C (23.0%). The most common nonprescription medications taken were aspirin (16.5%) and ibuprofen (13.0%). Most frequently, patients indicated that they were using supplements to promote health.

CONCLUSION

In this study, half the patients who took dietary supplements and almost half who took nonprescription medications did not report them to their healthcare provider on a written questionnaire, even though this information was requested. Patients should be specifically asked about use of dietary supplements and nonprescription medications, even if written information about such use is provided.

Measurement characteristics of the Women's Health Initiative food frequency questionnaire

PURPOSE

The Women's Health Initiative (WHI) is the largest research program ever initiated in the United States with a focus on diet and health. Therefore, it is important to understand and document the measurement characteristics of the key dietary assessment instrument: the WHI food frequency questionnaire (FFQ).

METHODS

Data are from 113 women screened for participation in the WHI in 1995. We assessed bias and precision of the FFQ by comparing the intake of 30 nutrients estimated from the FFQ with means from four 24-hour dietary recalls and a 4-day food record.

RESULTS

For most nutrients, means estimated by the FFQ were within 10% of the records or recalls. Precision, defined as the correlation between the FFQ and the records and recalls, was similar to other FFQs. Energy adjusted correlation coefficients ranged from 0.2 (vitamin B12) to 0.7 (magnesium) with a mean of 0.5. The correlation for percentage energy from fat (a key measure in WHI) was 0.6. Vitamin supplement use was common. For example, almost half of total vitamin E intake was obtained from supplements. Including supplemental vitamins and minerals increased micronutrient correlation coefficients, which ranged from 0.2 (thiamin) to 0.8 (vitamin E) with a mean of 0.6.

CONCLUSIONS

The WHI FFQ produced nutrient estimate, that were similar to those obtained from short-term dietary recall and recording methods. Comparison of WHI FFQ nutrient intake measures to independent and unbiased measures, such as doubly labeled water estimates of energy expenditure, are needed to help address the validity of the FFQ in this population.

Dietary supplement use by women at risk for breast cancer recurrence. The Women's Healthy Eating and Living Study Group

OBJECTIVE

To develop a method of collecting, organizing, and analyzing information on nutrient and nonnutrient dietary supplement use by women at risk for breast cancer recurrence as a component of nutrition assessment and monitoring, and to describe the characteristics associated with dietary supplement use in this population at enrollment in a clinical trial to prevent breast cancer recurrence.

DESIGN

Cross-sectional descriptive study design.

SUBJECTS

Women diagnosed with breast cancer within the previous 4 years (n=435).

ANALYSIS

Dietary supplements reported in four 24-hour dietary recalls were categorized according to primary nutrient and nonnutrient contents. Prevalence of dietary supplement use is described. Associations between supplement use and demographic and participant characteristics were examined using chi(2) analysis and logistic regression.

RESULTS

Dietary supplement use was reported by 80.9% of the women. Increased likelihood of supplement use was associated with demographic (eg, older age, higher level of education, white race vs other ethnic groups) and personal (eg, lower body mass index, moderate alcohol consumption) characteristics. Use of vitamin C and related compounds, other nutrients (eg, n-3 fatty acids, evening primrose oil), and herbal products was inversely associated with months since diagnosis; use of miscellaneous supplements (eg, shark cartilage) was directly associated with more advanced stage at diagnosis.

APPLICATIONS

Monitoring dietary supplement use is an important aspect of nutrition assessment, especially in populations with chronic health conditions or medical diagnoses. Demographic and personal characteristics, time passed since diagnosis, and stage of cancer at diagnosis are predictive of dietary supplement use by women at risk for breast cancer recurrence. Associations in this population may be present in other groups that are the object of nutrition intervention efforts.

Vitamin-mineral supplement use among preschool children in the United States

OBJECTIVE

To estimate the prevalence of recent supplement use in a national sample of preschool children and to examine the relationship of maternal and child characteristics, past maternal supplement use practices, familial, health services, and child health factors associated with supplement use.

METHODS

We used data on 8285 preschool children whose mothers were interviewed for the 1991 Longitudinal Follow-up to the 1988 National Maternal and Infant Health Survey. Data collection was conducted either by telephone or personal interview. The sample is representative of the estimated 3. 8 million US born children in 1988 and alive in 1991. The outcome measures are whether the child was given any vitamin and mineral supplements at least 3 days a week in the 30 days before the interview and the type of supplement received. Statistical techniques included bivariate and weighted multiple logistic regression analysis.

RESULTS

More than half of all US 3-year-olds (54.4%) were given some vitamin and mineral supplement. The most common supplements consumed were multivitamin-mineral with iron (59% of supplement users) and multivitamin-mineral without iron (26.4%). Children who received any supplements tended to have mothers who are non-Hispanic White, older, more educated, married, insured, receiving care from a private health care provider, have greater household income, and took supplements during pregnancy. Child health characteristics associated with supplement use included first birth order and having eating problems or poor appetites.

CONCLUSIONS

More than half of US preschool children used vitamin and mineral supplements. The sociodemographic and health predictors identified for supplement use suggest that groups at risk for nonuse are likely the same groups whose circumstances may predispose a need for supplementation.

Sweeteners, dyes, and other excipients in vitamin and mineral preparations

Multivitamins and mineral preparations are widely used for infants and children. All of these preparations contain a variety of excipients ("inert ingredients"). Excipients are generally safe; however, adverse effects have been attributed to them. Complete information about the excipients in various preparations is not readily available. The information about sweeteners, dyes, and other excipients (flavorings, preservatives, stabilizers, and fillers) for 41 chewable/liquid multivitamin and mineral preparations was obtained and tabulated. Sucrose was present in 63% (26/41) of preparations followed by lactose in 29% (12/41) of preparations. On average, a preparation contained two sweeteners. The FD&C yellow #6 (sunset yellow) was the most common dye, present in 46% (19/41) of the preparations followed by FD&C Red #40 in 29% (12/41). For 34% (14/41) of the preparations, no color or dye was identified by the manufacturers. The tables listing excipients and their adverse effects are presented and should be helpful to health care providers in selecting preparations containing individual excipients when an adverse reaction occurs or there exists a contraindication for using the excipient. The mandatory listing of all excipients is the only way to assure that physicians and consumers will be fully informed about the hidden ingredients.

Evaluating food fortification options: general principles revisited with folic acid

OBJECTIVES

This article uses folic acid as an example to illustrate some of the complex issues and general principles that emerge when evaluating fortification of the food supply as one possible means to address a public health recommendation.

METHODS

Distributions of current daily folate intakes from conventional foods and dietary supplements were estimated. Intakes that might result from fortification of cereal-grain products and ready-to-eat cereals at various levels for eight age-gender groups were also estimated by using the US Department of Agriculture's 1987-1988 Nationwide Food Consumption Survey.

RESULTS

The results illustrate that fortification of the US food supply tends to increase folate intakes of consumers at the high end of the intake distribution curves in the general population to a greater extent than it affects consumers at the low end of the intake distribution curves in the target population.

CONCLUSIONS

The effectiveness of food fortification options for a target population and the safety for the general population impose conflicting challenges that must be considered concurrently when making decisions about fortifying the US food supply.

Preventive care for patients with chronic illness. Multivitamin use in patients with cystic fibrosis

Routine supplementation with multivitamins is recommended for all patients with cystic fibrosis (CF). The purpose of this study was to investigate how well patients at a large CF clinic follow recommendations for taking multivitamins and what factors affect use. A questionnaire was developed and sent to the 150 patients actively followed at our center. Of the 80 patients who returned the survey, only 47% followed clinic recommendations. Of those patients not taking extra supplements, serum vitamin A and E levels varied widely, although most were within the normal range (vitamin A 11-87 micrograms/dL, tocopherol 0.4-2.3 mg/dL, tocopherol/cholesterol 3.0-9.6 mg/g). Only 25% of respondents had known insurance coverage for vitamins. Gender or educational level did not affect adherence; however, those with minimal pulmonary disease (forced vital capacity [FVC] greater than 70% of predicted) were more likely to take vitamins than those with moderate or severe disease (P < .05). In addition to malabsorption, poor adherence should be considered by both CF specialists and primary-care providers as a cause of low serum vitamin A and E levels, especially in patients with moderate to severe lung disease.

Vitamin and mineral supplement use and mortality in a US cohort

OBJECTIVES

Vitamin and mineral supplementation is a common practice in the United States, yet little is known about the long-term health effects of regular supplement use.

METHODS

To examine the relationship between reported use of supplements and mortality, we analyzed data from US adults 25 to 74 years of age who were examined in the First National Health and Nutrition Examination Survey (1971 to 1975), with vital status determined through 1987.

RESULTS

At baseline, 22.5% of the cohort reported using supplements regularly and 10.0% reported irregular use. The risk of mortality for regular supplement users was similar to that for nonusers. No consistent mortality benefits or risks of supplement use were found across a number of population subgroups. The risk for those who reported supplement use at both the baseline and a follow-up interview approximately 10 years later was similar to the risk for those who reported not using supplements at either interview.

CONCLUSIONS

We found no evidence of increased longevity among vitamin and mineral supplement users in the United States. Considering the wide use of supplements in the general population, the cost-effectiveness and the safety of supplement use need to be better defined.