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.

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.

Do time trends in food supply levels of macronutrients reflect survey estimates of macronutrient intake?

BACKGROUND: Two types of data may be used to estimate trends in food and nutrient intake by the US population: per capita food supply estimates and survey estimates of individual intake. Because these data vary markedly in measurement goals and methods, we examined whether trends in food supply and survey intake estimates for fat, carbohydrate, and protein are reflective of one another. METHODS: The data selected for comparison included all available survey estimates of mean intake by the US population (i.e., periodic estimates from 1965 to 1988) and all available per capita food supply estimates from a comparable time period (i.e., annual estimates from 1965 to 1985). RESULTS: The two types of data generally did not reflect the same trends. Furthermore, expressing macronutrient levels as percentage of calories rather than in grams affected the trend relationships. CONCLUSIONS: Our findings indicate that caution is needed in the selection and application of available data to estimate trends in macronutrient intake by the US population and in the interpretation of these data with regard to public health research, policies, and programs.

Evaluation of reactions to food additives: the aspartame experience.

Despite the widespread use of chemical food additives, few criteria exist to evaluate consumer reports of adverse reactions. We analyzed 231 consumer complaints associated with the food additive aspartame. We developed a methodologic approach to evaluate all complaints by adapting general criteria used to investigate adverse reactions to medications. Complaints were ranked according to the effects of cessation and rechallenge. Using this method, we found no clear symptom complex that suggests a widespread public health hazard associated with aspartame use; however, we identified some case reports in which the symptoms may be attributable to aspartame in commonly-consumed amounts. The systematic application of pre-defined review criteria, such as those described here, to monitor consumer complaints related to food additives will help identify products that warrant more focused clinical studies.