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Dietary supplement and food intake in women of childbearing age
Abstract
The relationship between dietary adequacy and supplement use was examined in 3,227 nonpregnant women aged 15 to 41 years from the first National Health and Nutrition Examination Survey. Twenty-five percent of the women used dietary supplements regularly; 67% of them consumed some form of multivitamin. Supplement users had a higher income and education, were more often white, had a leaner body composition, and were more likely to reside in the western United States than nonusers. Caloric intake of users and non-users was similar. However, independent of the supplements, the diets of supplement users contained significantly more dietary protein, phosphorus, iron, potassium, thiamin, and niacin than the diets of non-users. A considerable portion of both users and non-users had dietary intakes of less than 50% of the Recommended Dietary Allowances for calcium, iron, vitamin A, and vitamin C; however, a significantly greater proportion of supplement non-users had low intakes of iron and vitamin C. Supplement users generally consumed a more nutrient-dense diet and may be the individuals who least need supplements.
... Studies investigating associations between the use of supplements and disease or death have the potential to be influenced by several demographic and lifestyle factors. Previous studies have shown that supplement users sometimes differ from nonusers in characteristics such as the following: gender, race, socioeconomic status, age, use of tobacco, consumption of alcohol and level of exercise (Bender et al. 1992, Block et al. 1988, Koplan et al. 1986, Kurinij et al. 1986, Levy and Schucker 1987, Looker et al. 1988, Steward et al. 1985, Subar and Block 1990. Supplement users have also been shown to have higher nutrient intakes from diet than nonusers (Garry et al. 1982, Koplan et al. 1986, Kurinij et al. 1986, Looker et al. 1988 , although these associations were examined for specific types of supplements in only one study (Slesinski et al. 1996). ...
... Previous studies have shown that supplement users sometimes differ from nonusers in characteristics such as the following: gender, race, socioeconomic status, age, use of tobacco, consumption of alcohol and level of exercise (Bender et al. 1992, Block et al. 1988, Koplan et al. 1986, Kurinij et al. 1986, Levy and Schucker 1987, Looker et al. 1988, Steward et al. 1985, Subar and Block 1990. Supplement users have also been shown to have higher nutrient intakes from diet than nonusers (Garry et al. 1982, Koplan et al. 1986, Kurinij et al. 1986, Looker et al. 1988 , although these associations were examined for specific types of supplements in only one study (Slesinski et al. 1996). ...
... There is also evidence that supplement use may be associated with health factors (Bender et al. 1992, Block et al. 1988, Read et al. 1989, Shapiro et al. 1983, Subar and Block 1990. For example, supplement users were shown to have lower adiposity (Block et al. 1988, Kurinij et al. 1986, Subar and Block 1990. Bender et al. (1992) showed that supplement use was highest among persons who considered their health excellent or very good and lowest among those who considered their health good. ...
This study delineates demographic, lifestyle, dietary and health factors associated with the use of supplements at varying levels. Data are from a population-based cohort of 2,152 middle- to older-age adults living in Beaver Dam, Wisconsin. Information was collected by in-person interviews between 1988–1990. Associations were adjusted for gender and age. Use of supplements was more prevalent among women, persons with more than 12 years of education, those with relatively low body mass indices, persons with active lifestyles, and persons who never smoked as compared to current smokers (P ≤ 0.05). Supplement users had higher intakes of most of the micronutrients from food that were examined in this study, including the antioxidant vitamins C and E and certain carotenoids (P ≤ 0.05). Intakes of dairy products and also foods that are important sources of vitamin C and carotenoids were higher among users of supplements, but relationships differed by gender and by the type and level of supplement intake. These findings suggest that several factors need to be considered potential confounders in observational studies that examine the etiologic role of supplements in the occurrence of chronic disease.
... have higher nutrient intakes from diet than nonusers (Garry et al. 1982, Koplan et al. 1986, Kurinij et al. 1986, Looker et al. 1988) , although these associations were examined for specific types of supplements in only one study (Slesinski et al. 1996). There is also evidence that supplement use may be associated with health factors (Bender et al. 1992, Block et al. 1988, Read et al. 1989, Shapiro et al. 1983, Subar and Block 1990). ...
... For example, supplement users were shown to have lower adiposity (Block et al. 1988, Kurinij et al. 1986, Subar and Block 1990). Bender et al. (1992) showed that supplement use was highest among persons who considered their health excellent or very good and lowest among those who considered their health good. ...
... cereal or coffee ; dairy desserts and other nondairy desserts . Sweet baked goods included only doughnuts , cookies , cakes , pastry and pies . from NHANES II data , for a cohort of healthy elderly persons in New Mexico , for women of childbearing age in NHANES I , and in a nationallyrepresentative population in the U . S . ( Koplan et al . 1986 , Kurinij et al . 1986 , Garry et al . 1982 , Slesinski et al . 1996 ) . Two other studies did not show this association , although neither study examined nutrient density directly ( Bowerman and Harrill 1983 , Sem - pos et al . 1984 ) . Results from this study showing that dietary associations are not specific to one or two nutrients suggest that it may be d ...
This study delineates demographic, lifestyle, dietary and health factors associated with the use of supplements at varying levels. Data are from a population-based cohort of 2,152 middle- to older-age adults living in Beaver Dam, Wisconsin. Information was collected by in-person interviews between 1988-1990. Associations were adjusted for gender and age. Use of supplements was more prevalent among women, persons with more than 12 years of education, those with relatively low body mass indices, persons with active lifestyles, and persons who never smoked as compared to current smokers (P </= 0.05). Supplement users had higher intakes of most of the micronutrients from food that were examined in this study, including the antioxidant vitamins C and E and certain carotenoids (P </= 0.05). Intakes of dairy products and also foods that are important sources of vitamin C and carotenoids were higher among users of supplements, but relationships differed by gender and by the type and level of supplement intake. These findings suggest that several factors need to be considered potential confounders in observational studies that examine the etiologic role of supplements in the occurrence of chronic disease.
... Supplement users reported out-of-pocket expenditures of US$ 3.3 billion in 1997 for high-dose vitamin supplements and US$ 5.1 billion for herbal products [8]. Higher rates of adult vitamin and mineral supplement use are consistently reported among women, the better educated, and the more affluent [1,[9][10][11][12][13]. Supplement users report taking supplements to maintain health, prevent disease, and "feel better" [14][15][16]. ...
... Participants in this study appeared to represent many female supplement users reported in the literature. That is, supplement use is reported to be more prevalent among women, the better educated, and Caucasians, which is similar to the demographic characteristics of this sample [1,2,9,11,12,20]. The women in this study primarily obtained information about supplements from print material, family members, and friends. ...
... Finally, the most frequently consumed supplements among participants in this study (e.g. Vitamin C, Vitamin E, and a multivitamin) agreed with previous findings among supplement users [1,2,11]. ...
The use of dietary supplements is a popular form of health behavior, especially among women. Little research has been conducted to determine consumers' comprehension of supplement label information. Therefore, this research evaluated comprehension of supplement label information among women 25-45 years of age who consumed a dietary supplement > or =4 times per week. Participants (n=51) completed a written questionnaire about supplement practices, a 10-item knowledge test, and an individual interview about terms used on supplement labels. Participants answered 70% of the questions correctly on the knowledge test indicating adequate knowledge of dietary sources of nutrients. Knowledge of recommended dosages, dosing instructions, and instructions about inappropriate use of supplements for certain people also was adequate. However, misconceptions regarding the term "natural" on supplement labels, product claims, and testing for product safety existed among participants. Supplement users need additional education about supplement claims and testing for product safety and efficacy to make informed health care choices.
... Because women are frequent users of dietary supplements (6)(7)(8)(9)(10)(11)(12), women of childbearing age were the focus population for this research. This population also tends to consume dietary intakes less than 50 percent of the Recommended Dietary Allowances for some nutrients (26). ...
... Wellness. Some studies have indicated that those who take supplements probably do not need them, because of an intake high in fruits and vegetables, and incorporation of healthier eating practices (15, 16,19,26 (46). It has also been recommended that FDA adopt a rating system similar to the World Health Organization to help provide a distinction between those products that are considered relatively safe and beneficial to health against those items that may be potentially harmful with known adverse effects and/or are considered useless (29). ...
... The use of dietary supplements among females of childbearing age is low and in fact significantly lower among women with unintended pregnancies, as well as among African-American and Hispanic women (43) . For example, Kurinij and colleagues found that only 25 % of the 3277 women of childbearing age involved in the NHANES survey used dietary supplements on a regular basis (43) . ...
... The use of dietary supplements among females of childbearing age is low and in fact significantly lower among women with unintended pregnancies, as well as among African-American and Hispanic women (43) . For example, Kurinij and colleagues found that only 25 % of the 3277 women of childbearing age involved in the NHANES survey used dietary supplements on a regular basis (43) . Moreover, supplement users had a higher income and education and better nutritional status, were more likely to be White and had a leaner body composition. ...
Objective
Understanding nutrient intakes among women of childbearing age within the USA is important given the accumulating evidence that maternal body weight gain and nutrient intakes prior to pregnancy may influence the health and well-being of the offspring. The objective of the present study was to evaluate nutritional status in women of childbearing age and to ascertain the influence of ethnicity and income on nutrient intakes.
Design
Nutritional status was assessed using data on nutrient intakes through foods and supplements from the National Health and Nutrition Examination Survey. Biomarker data from the Centers for Disease Control and Prevention were used to assess nutritional status for selected nutrients. Poverty–income ratio was used to assess family income.
Subjects
White (
n
1560), African-American (
n
889) and Mexican-American (
n
761) women aged 19–30 and 31–50 years were included.
Setting
A nationally representative sample of non-pregnant women of childbearing age resident in the USA.
Results
African-American women had the lowest intakes of fibre, folate, riboflavin, P, K, Ca and Mg. Women (31–50 years) with a poverty–income ratio of ≤1·85 had significantly lower intakes of almost all nutrients analysed. Irrespective of ethnicity and income, a significant percentage of women were not consuming the estimated recommended amounts (Estimated Average Requirement) of several key nutrients: vitamin A (~80 %), vitamin D (~78 %) and fibre (~92 %). Nutrient biomarker data were generally reflective of nutrient intake patterns among the different ethnic groups.
Conclusions
Women of childbearing age in the USA are not meeting nutrient intake guidelines, with differences between ethnic groups and socio-economic strata. These factors should be considered when establishing nutrition science advocacy and policy.
... Tidligere undersøgelser har påvist, at kosttilskudsbrugere adskiller sig fra ikke brugere i køn, socioøkonomisk status, alder, brug af tobak, forbrug af alkohol, deres egen sundhedsopfattelse og deres aktivitetsniveau (Bender et al. 1992;Block et al. 1998,;Koplan et al. 1986;Kurinij et al, 1986;Steward et al. 1985;Subar & Block, 1990;Wingfield & Hagemann, 2004). ...
... None of the women had used dietary supplements on a regular basis before the study. Sup plement users generally consume a more nutrientdense diet and are probably in less need of supplemen tation than other individuals (Kurinij et al. 1986). The vitamin B-12 and vitamin C concentrations in the women without supplementation decreased signifi cantly during early pregnancy. ...
Folie acid and other vitamin deficiencies may play a role in the etiology of neural tube defects. The Medical Research Council Vitamin Study confirmed the beneficial effect of folie acid supplementation on the prevention of neural tube defects. However, the concen trations of vitamins other than folate were not a common feature of any of the former studies. We measured the concentrations of vitamin A, riboflavin, riboflavine-S'-monophosphate, flavine-adenine-dinucleo- tide, vitamin B-6, vitamin B-12, vitamin C, vitamin E, folate and ferritin in the serum of women who had previ ously had a child with a neural tube defect and were planning a further pregnancy. Vitamin and folie acid sup plements were supplied before conception to 44 high risk women before conception. Eighteen other high risk women not given supplements were the control group. We concluded that vitamin profiles do not form a suitable means for identifying women at risk for neural tube defects before pregnancy. This endorses the hypothesis that the beneficial effect of folie acid sup plementation on the prevention of neural tube defects is possibly at least partly due to the fact that it overrides a relative folie acid shortage caused by a metabolic dis order. J. Nutr. 123: 197-203, 1993.
... None of the women had used dietary supplements on a regular basis before the study. Sup plement users generally consume a more nutrientdense diet and are probably in less need of supplemen tation than other individuals (Kurinij et al. 1986). The vitamin B-12 and vitamin C concentrations in the women without supplementation decreased signifi cantly during early pregnancy. ...
Folic acid and other vitamin deficiencies may play a role in the etiology of neural tube defects. The Medical Research Council Vitamin Study confirmed the beneficial effect of folic acid supplementation on the prevention of neural tube defects. However, the concentrations of vitamins other than folate were not a common feature of any of the former studies. We measured the concentrations of vitamin A, riboflavin, riboflavine-5'-monophosphate, flavine-adenine-dinucleotide, vitamin B-6, vitamin B-12, vitamin C, vitamin E, folate and ferritin in the serum of women who had previously had a child with a neural tube defect and were planning a further pregnancy. Vitamin and folic acid supplements were supplied before conception to 44 high risk women before conception. Eighteen other high risk women not given supplements were the control group. We concluded that vitamin profiles do not form a suitable means for identifying women at risk for neural tube defects before pregnancy. This endorses the hypothesis that the beneficial effect of folic acid supplementation on the prevention of neural tube defects is possibly at least partly due to the fact that it overrides a relative folic acid shortage caused by a metabolic disorder.
The purpose of this study was to investigate the effect of iron supplementation on utilizations of various minerals, Ca, Mg, Na, K, Fe, Cu, Zn. Intakes, serum levels, and excretions of these minerals were analyzed and compared in rats fed diet with 100, 200, 400% of iron requirement (Fe, 2Fe, 4Fe groups) for 6 weeks. The feed intake, body weight gain and feed efficiency ratio were not significantly different among the groups. Serum Fe of 2Fe group was significantly lower than other two groups, and serum Zn of 4Fe group was highest. Mineral intakes were not significantly different among three groups. With iron supplementation, urinary excretions of Ca, Fe, Cu, Zn were elevated, but fecal excretions of minerals were not significantly different. And the daily retentions of Na and Fe were significantly elevated, but apparent absorbabilities of minerals were not significantly different. In summary, according to iron supplementation, mineral absorbabilities were not different but urinary excretions of some minerals were increased. Therefore, it could be suggested that adequate iron intake and well-balanced diet are more desirable than nutrient supplementation for mineral balance.
Objective: To determine the characteristics of adult New Zealand (NZ) supplement users. Design: Secondary data analysis of a cross-sectional national survey. Subjects: A total of 4636 adults aged 15 years and above.
Setting: Homes throughout NZ.
Methods: The National Nutrition Survey (NNS97), linked to the NZ Health Survey, had a multistage sampling design providing a representative sample of the NZ population aged 15 years and above. Secondary data analysis using logistic regression was used to determine characteristics of dietary supplement users (n = 2749) by a range of demographic, lifestyle and dietary variables.
Results: Income, marital status, Index of Deprivation (NZDep96 quartile) and place of residence were not independently associated with dietary supplement use. The odds of consuming dietary supplements over the previous year was increased in younger adults. Participants in the ‘NZ European and others’ ethnic group were the most likely to be supplement consumers compared with Maori and Pacific participants. Dietary intakes from food, for folate, riboflavin (males), vitamin C (females), niacin (females), dietary fibre (females) and calcium (males) were significantly higher in supplement users.
Conclusions: NZ supplement users are characteristically female, of ‘NZ European and others’ descent, well educated and relatively young. Nutrient intake from foods and beverages alone was adequate for those individuals who chose to include supplements in their diet.
There is considerable evidence supporting the role of various micronutrients in determining pregnancy outcomes such as low birth weight and prematurity. While some nutrients have been studied extensively (e.g.:calcium, zinc) much less is known about others (e.g.:vitamin B-complex). Methodologically, there is considerable variation in the types of study design ranging from cross-sectional studies to well designed randomized placebo-controlled trials (RCTs) most of which were conducted in developing countries among women who were not deficient and therefore less likely to benefit from the interventions. Inadequate sample size was another problem in many studies. The key conclusions of this review of the literature are 1) there is strong evidence primarily from developed countries that zinc, calcium and magnesium supplementation could improve birth weight, prematurity and hypertension particularly in high risk groups 2) folic acid can prevent neural tube defects, but the evidence on whether iron/and or folic acid supplements reduce the prevalence of low birth weight (LBW), prematurity and maternal mortality is limited 3) Severe iodine deficiency results in increase pregnancy loss, mental retardation and cretinism, but less is known for other outcomes especially in the case of marginal iodine deficiency 4) vitamin A supplements might reduce maternal mortality and perhaps LBW 5) vitamin C may play a role in the etiology of prematurity and 6) the B-complex vitamins, copper and selenium may have a role but very few experimental studies have been conducted to date. Most importantly, although there is evidence of interactions among several micronutrients at the metabolic level, very little is known about the significance of interactions for pregnancy outcomes. There is a need for well designed RCT's that will examine the role of selected nutrient interactions and multi vitamin-mineral supplements in improving pregnancy outcomes especially in developing countries where nutrient deficiencies do not occur in isolation and multiple micronutrients deficiencies are common.
Women frequently consume dietary supplements but the criteria used to select supplements have received little investigation. This research identified the decision-making criteria used for dietary supplements among women aged 25 to 45 years who consumed a supplement at least four times per week. Participants (N=51) completed an in-store shopping interview that was audiotaped, transcribed, and analyzed qualitatively for the criteria used to make supplement selections. Qualitative analysis revealed 10 key criteria and the number of times each person used each criterion was quantified. Cluster analysis identified five homogeneous subgroups of participants based on the criteria used. These included brand shopper, bargain shopper, quality shopper, convenience shopper, and information gatherer. Supplement users vary in the criteria used to make point-of-purchase supplement selections. Dietetics professionals can classify supplement users according to the criteria used to tailor their nutrition counseling and better meet the educational needs of consumers.
Attitudinal and demographic correlates to supplement use were investigated for 826 adults residing in Taipei. Demographic variables found to be significantly (p<0.01) related to supplement use included education, number in household and income. Supplement users tended to have higher education, fewer family members and higher income (P<0.001). The most frequent sources of information regarding health and supplements were magazines / newspapers and books. However, most adults relied on pro-fessional advice, especially physicians'. Three hundred and fifty of the respondents (42.4%) were regular / occasional supplement users. Only one hundred and thirty-five (19%) of the respondents wrote down supplement type for a recent condition. More users than non-users agreed with the statement that “supplements can both prevent and decrease the severity of illness, cold, and skin problems” (p<0.001). Fifteen questions on nutritional knowledge were tested, and 45.5% of the participants had scores of 9–10. Possible explanations and implications of the findings are discussed.
The 1980 Food and Drug Administration Vitamin and Mineral Supplement Use Survey and the 1986 National Health Interview Survey used similar questions and procedures to estimate and identify trends in the prevalence and magnitude of supplement usage in the United States. A comparison of the two surveys reveals that prevalence of supplement use among adults decreased slightly, from 42% in 1980 to 38% in 1986. The magnitude of supplement use has also decreased; users reported taking a mean of 2.15 supplements in 1980 compared with a mean of 1.77 in 1986. The prevalence of supplement users identified as light users increased from 42% in 1980 to 57% in 1986. Supplement usage was more likely and more intense among individuals who had one or more health problems and among individuals who perceived their health as very good or excellent. The findings indicate that supplement usage remains a widespread behavior linked to popular conceptions of good health and well-being but one that is susceptible to change.
This article reports usage of vitamin/mineral supplement information sources by adults in seven western states. Implications for targeting appropriate messages to supplement users are discussed.
Although vitamin-mineral supplement use is increasing in the United States, few researchers have examined whether supplement users have better nutritional status than do nonusers. Data from 10,515 persons examined in the second National Health and Nutrition Examination Survey (NHANES II) were used to compare mean dietary intakes of several nutrients and food groups, hemoglobin, mean corpuscular volume, transferrin saturation, erythrocyte protoporphyrin, and serum ferritin between regular supplement users and nonusers aged 16 to 74 years. Prevalences of impaired iron status also were compared between user groups. Users consumed more vitamin C and ate fruits and vegetables more frequently than did nonusers in all age/sex groups. No significant differences in mean iron status indicators were observed except in the 65 to 74 year age/sex groups: transferrin saturation among men and mean corpuscular volume, erythrocyte protoporphyrin, and serum ferritin among women. In each case, users had higher values than nonusers in this age group. Prevalences of impaired iron status did not differ between users and nonusers in any age/sex group. In general, iron status was not associated with supplement use.
Our objective was to evaluate the effect of regular use of nutritional supplements on serum vitamin C levels in a multivariable regression model, taking into account other dietary and demographic variables which may affect nutritional status.
We analyzed NHANES II data for subjects age 3 to 74. Analysis was limited to regular supplement users and nonusers, excluding irregular users. Multivariable regression analysis was performed with SUDAAN, incorporating sample weights and accounting for the complex survey design.
Regular supplement users had substantially higher serum vitamin C levels than nonusers (p < 0.001). The magnitude of the effect of supplement use on serum vitamin C was 0.23-0.33 mg/dL in children and teens, and 0.36-0.46 mg/dL in adults. In adults who smoked, bottom quartile vitamin C levels were 0.3 mg/dL in men and 0.4 mg/dL in women who did not use supplements, compared to 0.9 and 1.1 mg/dL in regular supplement users. There was a significant interaction of smoking and supplement use in men (p < 0.001).
Regular supplement use has a strong impact on serum vitamin C levels, independent of other dietary and demographic characteristics of supplement users which may favor improved nutritional status.
There has been increasing use of high-dosage zinc supplementation in the population, in particular as a potential treatment for age-related macular degeneration. We examined the relationship between fasting serum zinc and serum lipid levels in 778 adults, aged 22 to 80 years, who were control subjects in a multicenter, clinic-based case-control study. The samples were taken during 1987 to 1990, a time when vitamin/mineral supplementation was becoming increasingly common. We found that higher serum zinc levels, most notably those above the highest quintile, were associated with higher levels of total serum cholesterol, low-density-lipoprotein cholesterol, and triglycerides. No significant trend was noted for high-density-lipoprotein cholesterol. Previous studies demonstrated that high-dosage zinc supplements raise serum zinc levels. The possibility that use of such supplements can adversely affect serum lipid profiles suggests that chronic ingestion of such supplements should not be done without adequate medical supervision.
To examine the adequacy of dietary intake of calcium; folate; and vitamins C, D, E, B-6, and B-12 in premenopausal US women of differing ethnicity.
Analyses of single and duplicate 24-hour recalls were conducted to determine dietary intake during the Third National Health and Nutrition Examination Survey.
Three thousand five hundred eighty-five randomly selected women aged 20 to 50 years from across the United States who were not pregnant or lactating were examined between 1988 and 1994.
Usual nutrient intake distributions were estimated using the Iowa State University method for adjustment of the distribution. The Estimated Average Requirement cut-point method was used to determine the proportion of women with inadequate intake for each nutrient in each ethnic group.
More than 75% of women irrespective of ethnic group had usual intakes of calcium lower than the new Adequate Intake. More than 90% of the women had inadequate intakes of folate and vitamin E from food sources alone. More than half of smokers had inadequate intakes of vitamin C. Intakes of vitamins B-6 and B-12 were low in less than 10% of these women.
This article provides evidence that a high proportion of premenopausal US women are underconsuming a variety of nutrients. Dietary intakes alone are not currently adequate to meet the new recommended intakes. Nutritional supplement use is widespread and effective, but does not eliminate the concerns for at-risk populations. Awareness of the general inadequacies in intakes of vitamin E and folic acid at large, and in many women vitamin C as well, can help direct individual dietary recommendations and place the emphasis in group counseling on nutrients that are of widespread concern. In addition, foods rich in vitamins B-6 and of general nutritional benefit should be emphasized among African American women in the United States as a substantial proportion of this group is still showing inadequate intakes from foods.
Dietary and supplemental intakes were assessed from 3-day food records collected from 270 free-living, middle income and healthy men and women over 60 yr of age residing in the Albuquerque, NM vicinity. The 1980 Recommended Dietary Allowances (RDA) were used to assess adequacy of intake. Energy intake, as percentage of the RDA, was 90 +/- 23 (mean +/- SD) for men (n = 125) and 87 +/- 22 for women (n = 145). Mean daily protein intake was 83 g for men and 67 g for women and only 11% of men and 14% of women failed to receive at least 100% of the RDA for protein. Frequency and amount of vitamin and mineral supplementation was substantial. Approximately 60% of both men and women ingested one or more supplements; vitamins C and E were the most popular. In general, dietary intakes in this population appear to be adequate with the possible exception of vitamin D and calcium intakes in women.
Data on food supplement usage were collected from 2451 adults in seven Western states. No significant differences were determined among states. A majority (66.6%) of the sample used some form of food supplements, with 40.0% consuming one to three supplements per day. The archetype food supplement user was likely to be a young female with some college education, who believes that the nutritional quality of food has decreased in the last 10 yr and in the efficacy of supplements for disease prevention or cure, and primarily receives information concerning food and nutrition from books and health food stores. Correspondingly, one of the most frequently cited reasons for using food supplements, next to "to prevent colds and other illnesses" was "to make up for what is not in food." The three most frequently used food supplements, in rank order, were multiple vitamins, vitamin C, and multiple vitamins plus iron.
A method often used for computing the variance of a complicated sample estimate is to first apply the Taylor approximation to reduce non-linear forms of the variables to linear form. This article shows the useful results which can be obtained by merely reversing the order between selection units and component variables in this linear expression. The method is completely general (assuming that the samples are large enough to justify using the Taylor approximation) involving no restrictions on (a) the form of the estimate, (b) the number of random variables involved in the estimate, (c) the type, complexity or number of the sample designs involved in the estimate.
Health food buyers--both casual purchasers and confirmed customers of health food stores--were surveyed in Dallas and Houston. In both groups, users were generally in the middle class economically and in the active productive age brackets. Users in lower income groups spent larger proportions of their food budget in health food stores. The majority of confirmed users did so in the belief that such foods would provide health benefits, as health food proponents claim. Sixty-six per cent of the general public reported using vitamin and mineral supplements, compared with 93% of the confirmed health food users; the latter usually bought their supplements in health food stores, where megavitamins are likely to be promoted. Users among the general public, on the other hand, purchased supplements in drug stores and supermarkets as a rule.
Vitamin/mineral supplement use in the United States was assessed through a national telephone interview survey of an age-stratified random sample of 2,991 adults 16 years old and older. A vitamin/mineral supplement was defined as any product containing one or more of 33 specific vitamins, minerals, or "miscellaneous dietary components." Excluding pregnant/lactating women, 39.9% of the population consumed one or more supplements. Of those users, 52.4% consumed one supplement only; 10.9% consumed five or more (up to a maximum of 14 separate products). Confirming other research, above-average consumption of supplements occurred in the western United States. The most widely consumed product type was the single vitamin/miscellaneous dietary component (45.2% of supplement users). Vitamin C, either alone or in combination with other nutrients, was the most widely consumed nutrient (90.6% of supplement users). Use of supplements was more prevalent among women than among men in each of the three age groups examined: 16 to 24 years, 25 to 64 years, and 65 years and older. Although consumption of the B vitamins was more widespread among women than among men, more men than women consumed zinc, iodine, copper, magnesium, and manganese. There was a wide range of intake of both vitamins and minerals, which extended to 10 to 50 times the RDAs for individual nutrients.
Assume there are n i (i=1,2,⋯,s) samples from s multinomial distributions, each having r categories of response. Then define any u functions of the unknown true cell probabilities {π ij :i=1,2,⋯,s;j=1,2,⋯,r, where ∑ i=1 r π ij =1} that have derivatives of order up to the second with respect to π ij and for which the matrix of first derivatives is of rank u. A general noniterative procedure is described for fitting these functions to a linear model, for testing the goodness-of-fit of the model, and for testing hypotheses about the parameters in the linear model. The special cases of linear functions and logarithmic functions of the π ij are developed in detail, and some examples of how the general approach can be used to analyze various types of categorical data are presented.
There would be no controversy about the role of vitamin use in health and disease if all health professionals and those whose commentary on health matters is addressed to the public adhered to facts rather than promoting sensational anecdotes alleging efficacy, and if they heeded the axiom that, in matters of health, no substance is safe until proved safe, or effective until proved effective.1-4
Thousands of people have been misled by deceptive "nutrition information" from nutritionists whose credentials and anecdotal claims fall apart under close scrutiny.2-5 Among the code phrases often used to promote "nutritional" remedies of unproven safety and efficacy are "orthomolecular nutrition," "ecologic nutrition," and "nutritional," "metabolic," "holistic," "unconventional," "alternative," "unorthodox," and "nontoxic" therapy.2,3,6
LAETRILE AND PANGAMIC ACID
The most egregious, specious use of the code phrases of nutrition cultism is in connection with the lucrative sales of the noxious chemical substances pangamic acid and
A two-year survey of the dietary consumption and supplement use patterns of adult women was conducted at the University of Wisconsin-Madison. Participants were asked to record their diet on two randomly selected days per month over a two-year period. Each subject filled out an average of 19 records a year, for an overall 71% return rate. Because of the sampling design, it was possible to estimate each woman's "usual" or average daily dietary and total intake (diet plus supplements) of 15 nutrients. Many women were consuming usual amounts of energy, calcium, iron, magnesium, vitamin B-6, and, especially, zinc and total folate that were 30% to 50% below recommended levels. It was also found that the women generally took vitamin/mineral supplements for nutrients already adequately supplied in the diet. Low nutrient intakes may have been due, in part, to underreporting of food intakes.
Dietary histories and information concerning the use of nutritional supplements were obtained from 51 randomly selected residents of an Orange County, CA, retirement community. The nutrients for which dietary intakes were most apt to fall below 100% of the 1980 Recommended Dietary Allowance were: calcium, in both sexes; energy, in males; and iron, thiamin, riboflavin, and niacin in females. With the exception of calcium, few subjects had intakes below two-thirds of the Recommended Dietary Allowances. These findings are similar to those reported in previous dietary surveys of the elderly. Vitamin and mineral supplements were consumed by 72% of the subjects; such consumption was unrelated to dietary intake. Supplemental vitamin C was consumed by 67% of the subjects in amounts ranging from 30 to 5200 mg daily; supplemental vitamin E was taken by 51%, with amounts ranging from 8 to 1000 IU daily. Supplement use by this population is one of the highest reported among the elderly, an effect that may result from the affluence of the community, its geographic location, and from a high level of nutritional consciousness among its residents.
Mean energy and nutrient intakes from food of 150 users or non-users of nutrient supplements were compared. Independent of supplement use, no significant differences in nutrient intakes between the two groups were observed. Some significant differences were noted in average nutrient intakes between men and women of the same age group. Fifty-three percent of the subjects reported the use of supplements, with multivitamins and ascorbic acid most often taken. Potentially toxic intakes of vitamins A, C, and E were observed for a few subjects. In general, nutrient intakes from food met the Recommended Dietary Allowances.
A dietary questionnaire which included items relating to the use of specific vitamin preparations was sent to a randomly selected group of 2000 female, registered nurses aged 30 to 59 yr residing in 10 states. Among the 1742 women (87%) who returned completed questionnaires, the rates of use were 38% for multiple vitamins, 4% for specific preparations of vitamin A, 23% for vitamin C, and 15% for vitamin E. Women who used specific preparations of vitamins A, C, and E generally consumed them in quantities many times greater than the RDA. Use of specific vitamin preparations was found to increase with age and was highest in California.
SURREGR: Standard errors of regression coefficients from sample survey data
- M M Holt
Diet and Iron Status, a Study of Relationships: United States, 1971-74
- J D Singer
- P Granahan
- N N Goodrich
- L D Meyers