New Dietary Guidelines Identify Vitamin Shortfalls
As all manner of nutrition and health professionals have scrutinized proposals for the new Dietary Guidelines, it has become clear—or has it?—that many Americans aren't getting adequate amounts of certain vitamins.
By Frances Katz, Contributing Editor
The finalized USDA Dietary Guidelines are anticipated sometime in 2005. The committee reported low dietary intakes of vitamin E among children, and vitamins A, C, E and folate were considered low enough to be of concern among adults.
Not all the experts agreed the shortfall is as serious as it appears. Dr. Fergus Clydesdale, Dietary Guidelines committee member and chair of the Food Science Department at the University of Mass., complains the shortfalls are derived from a database of foods that don’t take fortified foods into consideration. “Vitamin C probably isn’t much of a problem; neither is vitamin A. There may be a shortfall with vitamin E, but it’s probably not major,” Clydesdale says.
One vitamin, folic acid, was reported to be at levels below the estimated average requirement. However, the authors of the report noted these intakes were measured before the regulation required fortification of enriched grains with folic acid. Folate fortification was added on indication the nutrient was low in too many diets, and because of extensive research associating folate deficiency with increased incidence of spinal defects in newborn babies.
In studies, folate intake rose markedly after fortification when compared to prefortification databases. Still, some studies suggest folate deficiencies may remain a problem. There are indications low-carb diets may cause lowered intake of folate, as the fortification of the nutrient would not be effective for those who are consuming very low-carb diets.
|Calf's liver (above), lentils, several varieties of beans, asparagus, spinach and collard greens are foods that are naturally high in folate.|
The difficulties with keeping everyone in the food segment happy starts with the second paragraph of the Nutrient Intake Goals, where the report notes, “One premise of the Dietary Guidelines Advisory Committee is nutrients consumed should come primarily from foods.” The commentary notes studies show consumers who eat a diet rich in beta-carotene, the natural precursor of vitamin A, have a lower rate of several kinds of cancer. In contrast, studies have not shown taking beta-carotene in pill form decreases the risk of cancer.
It is possible beta-carotene and other nutrients are most beneficial to health when they are consumed in a natural form and in combination with each other. This occurs when a person consumes foods such as fruits, vegetables (including legumes) and whole grains.
One food scientist who supports the new report’s findings is Mary Mulry, Ph.D., senior director of research, development, and standards for Wild Oats Markets, Inc. Boulder, Co. (www.wildoats.com
). Mulry suggests consumers “take a multivitamin as a safety net,” but concurs most vitamins and nutrients should come from food.
Last year Mulry helped develop a pizza made with whole grain flour, because whole wheat “doesn’t require folic acid fortification; the whole grain is included,” says Mulry. “Pizza is a major food component of a meal, and should include as much nutrition as possible. Cookies, on the other hand, may use some enriched flour, because they aren’t a major component of diet. But we like to see some whole grain flour in any grain-containing food, and that’s quite do-able.”
Mulry also reminds consumers, “Wheat isn’t the only healthful grain. Rye, barley, and oats have a lot to contribute.” She believes a major problem with the old Dietary Guidelines pyramid was it included a lot of grain servings, but didn’t mention whole grains prominently.
Kimberly Goode, vice president of worldwide communications for Kellogg Co., Battle Creek, Mich. (www.kelloggs.com
) notes the cereal maker “remains committed to providing a wide variety of products and information to help consumers improve their diets. We are reviewing the USDA's scientific report and plan to submit comments before the September deadline. Kellogg has been a long-standing advocate of using the USDA dietary guidance on our product packaging all over the world. We believe it's an important educational tool to help consumers choose a well-balanced diet.”
Tropicana (now a division of PepsiCo, Inc., Purchase, N.Y.), and Minute Maid, a division of Coca-Cola, Atlanta, Ga., are introducing fortified juice products complete with vitamins A, C, E and calcium. Also, in response to a variety of concerns about sugar, both firms are introducing an orange beverage containing sugar-reduced juice formulated with high intensity sweeteners. Spokespersons for both firms note advances in vitamin technology make it possible to incorporate oil-soluble vitamins into a water-based juice product.Intake vs. Absorption
In food labeling, the amounts of vitamins recommended coincide with the RDA level. “We expect food fortification to grow and, in light of changing agricultural practices, researchers see this as a necessity,” says Alice Wilkinson, Ph.D., director of research for Watson Foods Company, Inc., West Haven, Conn. (www.watsonfoods.com
). Watson Foods is a major supplier of vitamins for food processors. “Assuming fortification is done according to regulations, we expect to see improvements in the overall health of the population especially considering although the guidelines are carefully designed, they cannot account for the inevitable nutrient deficiencies of many who do not meet the definitions of (what is considered) good health.” Wilkinson noted many people don’t eat as well as they should. For those people, fortification supplies an important safety net.
In addition to dealing with imperfect diets, a growing body of research indicates for some physical conditions, multiples of certain vitamins may be effective. Certain vitamins may be consumed in sufficient quantity, but a portion of the population has a reduced ability to use those nutrients. One example is vitamin B12, which is generally consumed in large enough quantity. However, 10 to 30 percent of people over age 50 may be unable to absorb the naturally occurring vitamin.
|Functional Foods Fact Sheet: Antioxidants |
To help improve the public’s understanding of emerging research on functional foods, the International Food Information Council (IFIC) Foundation released the first in a series of referenced materials on various food components and their potential health benefits, "Functional Foods Fact Sheet: Antioxidants."
The fact sheet contains information on the health effects, research, and dietary sources of antioxidants; a “bottom line” section summarizes the research and current recommendations. Links to several informational Web sites are also included. The fact sheet is available on the IFIC Foundation Web site at www.ific.org/publications/factsheets/antioxidantfs.cfm.
The committee recommended persons over age 50 should meet their requirement of B12 by consuming fortified foods or by taking supplements. Deficiency of B12 leads to the development of serious anemia. A similar situation exists with vitamin D, in which about a third of consumers over age 50 require more than the RDA of vitamin D to properly absorb calcium. In those cases, larger quantities of the vitamin may be required to avoid rickets and other related diseases. Although still relatively rare, there has been some concern among the medical community that rickets cases may be on the rise.
Where diseases are not specifically considered dietary based, considerable research has gone into determining the effects of specific vitamins and minerals. The value of large amounts of vitamin C came in to question after the late Dr. Linus Pauling recommended doses of up to several grams per day of the antioxidant vitamin to cure heart disease and cancer. His experiments proved difficult to replicate. Some studies even indicate overdoses of C could lead to a number of complications ranging from rashes to a reversal of its antioxidant effect. However, interest in antioxidant vitamins as a curative still remains a valid area of research.
Last year, a team of scientists at Brandeis University, Waltham, Mass., established that while vitamin C supplements could not be shown to have a significant protective effect over the six-year period of their study, vitamin E supplements at levels greater than 100 IU per day were shown to reduce all-cause mortality 27 to 34 percent, coronary heart disease mortality by 41 to 47 percent and cancer mortality by more than 20 percent.
A key difference to the study was the vitamin E was combined with milk protein. The combination appeared to greatly enhance the vitamin’s absorbability. Vitamin E is fat soluble, and the milk protein apparently assisted to a significant degree.
Similarly, Bausch & Lomb, Rochester, N.Y., completed research indicating the use of dietary supplements could promote retinal health by arresting macular degeneration through the use of a uniquely formulated nutritional supplement. The company developed a supplement in tablet form which contains higher than normal amounts of vitamin C, E, beta carotene, zinc, and copper. The amounts of these nutrients are approximately seven to 10 times the RDA of vitamin C; 13 to 18 times the RDA of vitamin E; six to 10 times the RDA of vitamin A (in the form of beta-carotene); four to seven times the RDA of zinc; and contain at least 1.6 mg copper.
In these and other cases, the vitamins may be used as supplements or functional foods with specific utility, or as medical foods, to address any shortfalls in vitamins and minerals through inadequate dietary intake.