Nutritional Requirements Throughout the Life Cycle: Later Years

Due to reductions in lean body mass, metabolic rate, and physical activity, elderly persons require less energy than younger individuals. Some DRIs for elderly persons differ from those of younger adults. For example, in order to reduce the risk for age–related bone loss and fracture, the DRI for vitamin D is increased from 200 IU/day to 400 in individuals 51 to 70 years of age and from 200 IU/day to 600 IU/day for those >70 years of age. Suggested iron intakes drop from 18 mg per day in women ages 19 to 50 to 8 mg/day after age 50, due to iron conservation and decreased losses in postmenopausal women, compared with younger women.¹

Some elderly persons have difficulty getting adequate nutrition because of age– or disease–related impairments in chewing, swallowing, digesting, and absorbing nutrients.⁴⁰ Their nutrient status may also be affected by decreased production of digestive enzymes, senescent changes in the cells of the bowel surface, and drug–nutrient interactions⁴⁰ (see Micronutrients). The results can be far–reaching. For example, a study in elderly long–term care residents demonstrated frequent deficiency in selenium, a mineral important for immune function.⁴⁰ In turn, impaired immune function affects susceptibility to infections and malignancies. The role of vitamin B₆ in immunity also presents a rationale for higher recommended intakes for elderly persons.⁴¹

Nutritional interventions should first emphasize healthful foods, with supplements playing a judicious secondary role. Although modest supplementary doses of micronutrients can both prevent deficiency and support immune function (see Upper Respiratory Infection), overzealous supplementation (eg, high–dose zinc) may have the opposite effect and result in immunosuppression.⁴² Multiple vitamin–mineral supplements have not been consistently shown to reduce the incidence of infection in elderly individuals.⁴³ The effects of multiple vitamin–mineral supplementation on cancer risk may be mixed, with some studies showing benefit,⁴⁴ and others showing increased cancer risk related to supplement use (eg, increased risk for prostate cancer⁴⁵ and non–Hodgkin’s lymphoma in women).⁴⁶ Risks may be specific to certain nutrients. For example, high calcium intake has been associated with prostate cancer risk (see Prostate Cancer), while other micronutrients have protective effects.

Alcohol intake can be a serious problem in elderly persons. The hazards of excess alcohol intake include sleep disorders, problematic interactions with medications, loss of nutrients, and a greater risk for dehydration, particularly in those who take diuretics. Roughly one–third of elderly persons who overuse or abuse alcohol first develop their drinking problems after the age of 60 years.⁴⁷