More effective nutrition label formats are not necessarily preferred.

An experimental design was used to compare performance and preference for five nutrition label formats. Four performance measures--accuracy and false-positives in identifying nutrient differences, time required, and correctness in judging which product was more nutritious--were derived from a product-comparison task. A sample of 1,460 food shoppers over 18 years old was recruited by a shopping mall-intercept method. Results of the study demonstrated that preferences and performance do not necessarily agree. The Control format, which had no nutrition profile information, performed the best but was liked the least. The Adjectival format, which provided nutrition profile information in the form of descriptive adjectives, was the most preferred. Results also showed that listing Daily Reference Values or nutrition profile aids increased preference but either did not affect performance or decreased it, depending on the specific aid and performance measure. Formats that some subjects liked for having adequate information others disliked for being hard to use. Formats that some subjects liked for being easy to use others disliked for having inadequate information. Age, education, and race were related to all of the performance measures except judgment of relative nutrition. Only gender was related to preference. Results of the study are useful as guidance for the development of consumer education materials.

Trends in prevalence and magnitude of vitamin and mineral supplement usage and correlation with health status.

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.

Patterns of nutrient intake among dietary supplement users: attitudinal and behavioral correlates.

A national telephone interview survey of an age-stratified random sample of 2,991 adults, aged 16 and over, provided detailed information from 1,142 vitamin and mineral supplement users about their nutrient intake patterns from dietary supplements. Dietary supplement users were divided into four groups (Light, Moderate, Heavy, and Very Heavy) on the basis of the type and amount of nutrient intake from supplements. The Light, Moderate, Heavy, and Very Heavy nutrient intake groups accounted for 42%, 16%, 28%, and 14%, respectively, of the total users. Young supplement users (aged 16 to 25) tended to be in the Light user group. Older adults (aged 41 to 64) and residents of the western United States tended to be in the Heavy and Very Heavy user groups. Users in the Light and Moderate nutrient intake groups generally used only one broad-spectrum vitamin and mineral product. Users in the Heavy and Very Heavy groups were typically taking two or more specialized vitamin and mineral products at a time as part of a personalized supplement regimen. Heavy and Very Heavy nutrient intakes were associated with more frequent visits to health food stores, greater nutrition activity, and less physician involvement. Light and Moderate nutrient intakes were more likely to be associated with a defensive interest in avoiding nutritional deficiencies. The implications of generally different motivations for dietary supplement use are discussed in the context of public information strategies.

Vitamin/mineral supplement use: a telephone survey of adults in the United States.

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.