10

Part I Introduction to Nutrition Care in Older Adults

from the metabolism of muscle tissue. The daily pro- duction of creatinine is related to the body’s total LBM and is produced at a fairly constant rate. The CHI has been adopted for evaluation of LBM in all age groups of individuals who might be protein-energy malnour- ished (49).

The topic of the mortality differences between weight categories has sometimes been controversial. Weight loss in older adults is associated with increased mortality (45-47,50,51). Weight loss can, and frequently does, occur at multiple points along this continuum. In a study of mortality (all causes) of older adults, a meta-analysis of BMI did not find that overweight was related to an increased risk of mortality. However, in another meta-analysis relative to normal weight, obesity was associated with significantly higher all-cause mortal- ity (52,53) and deleterious effects of underweight increase with increasing age, since sarcopenia is more likely to result when an already thin person loses weight. In general, higher rates of weight loss are associated with increasing age. After controlling for age, Knudtson et al (51) found that detrimental weight loss appeared to be associated with higher BMI, higher rates of chronic disease, smoking, excessive alcohol intake, lower base- line blood pressure, low serum albumin, low hematocrit, and low total serum cholesterol. Weight maintenance as age advances; increased physical activity; and movement designed to promote improved strength, flexibility, balance, and mainte- nance of muscle mass are the best recommendations regarding body weight in older adults that can be offered at this time. The Centers for Disease Control (CDC) (54) has listed minimal and more vigorous guidelines for healthy individuals age 65 and older regarding physical activity. These guidelines are sum- marized in Box 1.4.

NUTRIENT REQUIREMENTS The Dietary Reference Intakes (DRIs) offer Recom- mended Dietary Allowances (RDAs) or Adequate Intakes (AIs) when no RDA has been formulated, with specific guidelines for older adults. Recommendations are offered for two categories of older adults: those ages 51 to 70 years and those older than 70 years (20,55). Table 1.4 (see pages 12–13) lists nutrient rec- ommendations for men and women specific to these age groups (56).

Recommendations regarding estimated energy requirement (EER) are based on height, weight, BMI, and activity level and are derived from the following regression equations, based on data using the doubly labeled water method (57):

Men: EER = 662 − 9.53 × Age (y) × PA × (15.91 × Wt [kg] + 539.6 × Ht [m])

Women: EER = 354 − 6.91 × Age (y) × PA × (9.36 × Wt [kg] + 762 × Ht [m])

Where PA refers to coefficient for physical activity levels (PALs),

PA = 1 if PAL ≥ 1 < 1.4 (sedentary) PA = 1.12 if PAL ≥ 1.4 < 1.6 (low active) PA = 1.27 if PAL ≥ 1.6 < 1.9 (active) PA = 1.45 if PAL ≥ 1.9 < 2.5 (very active)

Vitamin D status in all Americans is of increasing concern, especially in older adults. In the 2011 update of Dietary Reference Intakes for Calcium and Vitamin D, the Institute of Medicine set dietary vitamin D requirements at 600 IU for men and women aged 51 to 70 years and 800 IUs for men and women older than 70 years. Cholecalciferol is preferred due to its increased bioavailability to maintain adequate concen- trations (80 mmol/L) of 25 hydroxyvitamin D (25[OH] D), the biomarker for vitamin D status. There is no current agreement on normal 25(OH)D levels, but the consensus opinion is that the normal range should be determined based on normal parathyroid hormone levels (58). Vitamin D supplementation of 1,000 to 2,000 IU daily is often recommended for older adults with poor milk intake or limited sunlight exposure, especially in light of other studies that suggested older adults may require higher doses and take longer to reach the normal baseline (59,60).

Supplemental calcium is often recommended for individuals who are unable to consume adequate food sources of calcium. The current recommendation for older adult males aged 51 to 70 years is 1,000 mg/d, and for men older than 70, it is 1,200 mg/d. The RDA for woman aged 51 years and older is 1,200 mg/d (59). Because of the normal changes of the gut that occur with aging, supplementation of vitamin B-12 (2.4 mcg/d) is also recommended. With vitamin B-12, older adults may experience achlorhydria related to a history of chronic Helicobacter pylori infection, chronic protein pump inhibitor use, and autoimmune conditions (eg, diabetes, autoim- mune thyroid disease) (60) and may malabsorb protein-bound food sources of this vitamin. Due to the high incidence of older adults unable to absorb protein-bound B-12, the DRI for people over the age of 50 includes the recommendation that the majority of B-12 should come from fortified foods or supple- ments (which are not protein-bound and therefore more easily absorbed). The widespread use of H2 receptor agonists and proton pump inhibitors in