Micronutrient adults

Kant, A. K. and B. I. Graubard (2007). Ethnicity is an independent correlate of biomarkers of micronutrient intake and status in American adults. J. Nutr. 137(11) 2456-2463. 

The increases in energy, protein and micronutrients in food are one of the factors responsible for improved defence mechanism in the body which decreased the incidence of infectious diseases. These factors have also helped to reduce the parasite load in many countries. The diet has also led to an increase in the size of children, teenagers and adults. 

Nutrients are the constituents of food necessary to sustain the normal functions of the body. All energy is provided by three classes of nutrients fefe, carbohydrates, protein, and in some diets, ethanol (Figure 27.1). The intake of these energy-rich molecules is larger than that of the other dietary nutrients. Therefore, they are called the macronutrients. This chapter focuses on the kinds and amounts of macronutrients that are needed to maintain optimal health and prevent chronic disease in adults. Those nutrients needed in lesser amounts, such as vitamins and minerals, are called the micronutrients, and are considered in Chapter 28. 

Kwashiorkor is a type of malnutrition associated with insufficient protein intake, usually affecting children aged 1-4 years, although it can also occur in older children and adults. It is likely caused by a combination of factors (protein deficiency, energy and micronutrient deficiency). The absence of lysine in low-grade cereal proteins (used as a dietary mainstay in many underdeveloped countries) can lead to kwashiorkor. 

H. F. DeLuca in R. B. Olfin-Slater and D. Kritchevsky, eds.. Nutrition and the Adult Micronutrients, Plenum Press, New York, 1986, p. 205. 

They differ from micronutrients by the quantities required according to nutritional guidelines, daily macronutrient intake for an adult should include 130 grams of carbohydrates, about 50 grams of protein, 40 grams of fat, and 30 grams of fiber. All of the macronutrients featured in the following sections are considered essential for health and are present in all plant foods and superfruits in different amounts. 

The optimal dietary requirements of vitamin E for humans are not yet known, especially with the emergence of new paradigms regarding adequate levels of dietary micronutrients (Chalem, 1999). Recommendations in the United States and Canada have been reevaluated, and a new concept of Dietary Reference Intake (DRI, 2000) was issued for vitamin E and other antioxidants. The DRI recommendation should prevent specific deficiency disorders, support health in general ways and minimize the risk of toxicity, which carries more tasks than the previous recommendations (DRI, 2000). Accordingly, the recommendations for intakes were set to higher levels than previously. Estimated Average Requirements (EAR) for adults, both men and women, were set to 12 mg a-tocopherol/day, RDA to 15 mg/day and Tolerable Upper Intake Level (UL) to 1000 mg/day. Moreover, the EAR and RDA are based only on the 2R-stereoisomeric forms of a-tocopherol, because the other vitamers... 

TABLE 30-1 Oral and Intravenous Micronutrient Intakes for Adults ... 

Shenkin A. Adult micronutrient requirements. In Payne-James J, Grimble G, Silk D, eds. Artificial nutrition support in clinical practice. London GMM, 2001 193-212. 

Shenkin A. Micronutrients in adult nutritional support requirements and benefits. Curr Opin Clin Nutr Metab Care 1998 1 15-9. 

Misra S, Kirby DF Micronutrient and trace element monitoring in adult nutrition support. Nutr Clin Pract 2000 15 120-126. 

Selenium is known to be an essential micronutrient for humans and other animals both inadequate and excessive selenium intake can cause adverse health effects. However, most people in the United States are unlikely to suffer from selenium deficiency. The current recommended dietary allowance (RDA) for selenium established by the Food and Nutrition Board of the National Research Council is 55 pg/day for adults. Adverse health effects due to selenium are generally observed at doses at least 5 times greater than the RDA. 

As a component of glutathione peroxidase and the iodothyronine 5 -deiodinases, selenium is an essential micronutrient for humans. Its role in the deiodinase enzymes may be one reason that children require more selenium for growth than adults. Selenium is also a component of the enzyme thioredoxin reductase, which catalyses the NADPH-dependent reduction of the redox protein thioredoxin. Other selenium-containing proteins of unknown functions, including selenoprotein P found in the plasma, have also been identified. Excess selenium administered as selenite and selenate has been shown to be metabolized to methylated compounds and excreted. 

IV.A), this ion is currently officially recognized as an essential micronutrient for humans (577, 578). The recently published values of Dietary Reference Intakes of Crflll) in the United States and Canada (ranging from 0.2 to 5.5 pg day for infants or from 20 to 45 pg day for adults) (578) are significantly lower than the previously accepted values of Recommended Dietary Allowances (RDA) (from 10 pg day for infants to 200 pg day for adults) (577). Measurements of Cr(III) contents in food sources suggested that up to 90% of the population in industrialized countries receive less than adequate amounts of dietary Cr(III). These amounts can be further decreased by carbohydrate- and fat-based diets, which promote Cr(III) excretion (3). As the biological activity of Cr(III) has been related to improvements in glucose and fat metabolism (579), the use of... 

The brain makes acetylcholine from choline, an essential nutrient that is found in fat molecules called phospholipids. The most common form is phosphatidylcholine, also in the food supplement lecithin (derived firom egg yolks or soy). According to the Linus Pauling Institute Micronutrient Information Center, adequate intake levels of choline for adults are 550 milligrams per day for men and 425 milligrams per day for women. You will find relatively rich sources of choline in food portions such as 3 ounces of pan-fried beef liver (355 g)> 1 cup of toasted wheat germ (172 mg), 1 large egg (126 mg), or 2 cups of chopped cooked broccoli (126 mg). 

Mineral requirements are related to body composition and, on this basis, Ca and P are needed in considerably greater amounts than the lesser micronutrients such as Fe, Mn or Mo. A daily intake of 1.0-1.5 g of P and 1.5-2.0 g of Ca is considered necessary for average adult humans. 

Cultural and genetic factors limit the applicability of these studies to health care in the United States. Though the effects of mild to moderate malnutrition are more subtle, they may also be more prevalent than previously assumed. These considerations apply to micronutrient status, such as for iron in children, and to a spectrum of adult deficiencies, primarily... 

What might appear to be nutritionally unimportant or of only minor importance in the adult can be extremely important in the infant who may increase his body mass by 50 to 75 per cent during a few weeks of total intravenous nutrition. This dilutional factor alone might be enough to significantly deplete body stores of some micronutrients. 

Allen, L.H., Peerson, J.M., and Olney, D.K., 2009b. Provision of multiple rather than two or fewer micronutrients more effectively improves growth and other outcomes in micronutrient-deficient children and adults. Journal of Nutrition. 139 1022-1030. 

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