THE INTAKE OF VITAMINS FOR FUTURE HEALTH

The Intake of Vitamins for Future Health

The Intake of Vitamins for Future Health

Introduction

Nutrition is a fundamental necessity with special considerations in the older adult. Maintaining adequate nutrition is essential to healthy aging, yet this population is at high risk for malnutrition and undernutrition, primarily because of physiological and social changes that transpire over the course of their lives. Malnutrition exists in community-dwelling, hospitalized, and institutionalized older adults and is associated with increased morbidity and mortality. Macronutrient (protein energy) and micronutrient (vitamins and minerals) deficiencies are common. (Hanawa et al, 1992, 20-24) Age-related changes in physiology, metabolism, and functional status alter nutritional requirements. For example, there is redistribution of muscle mass and fat content that changes energy requirements as well as immunological changes that increase susceptibility to infection. Gradual reduction in alimentation is also common and is recognized as anorexia of aging. Other contributors to the propensity for malnutrition include underlying medical conditions, medication use, an unsupportive social environment, and dentition or feeding issues. The consequences of malnutrition can affect cognitive and functional abilities and, if severe, can be detrimental to the older adult. Osteoporosis, for example, results from inadequate calcium and Vitamin D intake and is associated with a higher risk of hip fracture. (Hiles et al, 1974, 366-379) Hip fractures consequently have a high mortality rate. Nutritional assessments should identify those at risk and allow for developing a plan that focuses on nutrient replacement and preserving functional independence while maintaining quality of life.

Physiological Changes of Aging

Reduced Metabolic Rate

The most dramatic physiological change that affects nutrition occurs in body composition. Lean body (muscle) mass decreases and fat content increases naturally over the decades of life. This situation is preventable with nutritional balance and exercise. Muscle mass is slowly lost because there is a reduction in protein synthesis and an inability for the body to retain by-products for efficient muscle production as the body ages. (Horio et al, 1967a, 1-11) Loss of muscle mass (or sarcopenia) begins after 25 years of age and accelerates after 45 years of age. The development of sarcopenia is multifactorial in origin and is due to a reduction of motor neurons, a decrease in anabolic hormonal influences, and disuse atrophy. Sarcopenia influences muscle strength, gait, and balance and also contributes to the increased risk of falls and frailty. The biggest impact of sarcopenia on nutrition is reduced energy requirements and metabolism. This reduction in metabolic rate can be countered by increasing exercise and protein intake to maintain healthy muscle mass. Particular attention must be given to the increase in protein requirements of the older adult because proteins are not produced or used as efficiently by the aging body. In general, 1 milligram per kilogram (mg/kg) of body weight per day of protein consumption is considered to be adequate. (JECFA, 1982, 297-319)

The composition of body fat also changes in quantity and location. Body fat increases over time and is associated with metabolic consequences such as insulin resistance, elevation of triglycerides, and ...