Influence of Expectations of Aging on Older Women’s Use of Dietary Supplements Using the Health Promotion Theory

Abstract

The use of vitamins, minerals and herbal supplements by older adults is increasing and changing. There are concerns about supplement quality, safety, and vitamin D overuse. Little is known about supplement use by nursing home residents and about factors that influence older women to use supplements. The current study describes the supplement use of 247 nursing home residents and 110 independent living women 65 years or older in the Midwestern United States. A secondary analysis of 247 medication administration records describes the prevalence of vitamin, mineral, and herbal supplement use of nursing home residents. Using the health promotion theory, the author examined factors that influence independent living older women’s use of supplements. The research hypothesis for the study was: controlling for age, comorbidity and education level, expectations of aging, self-efficacy, and prior related behavior will predict vitamin, mineral and herbal supplement use. A cross-sectional descriptive survey included expectations regarding aging, general self-efficacy, the Self-Administered Comorbidity Questionnaire, a 24-hour supplement recall and an inventory of supplement use in the past month. A multiple regression model was used to determine predictors of vitamin, mineral and herbal supplement use. Education level, prior use of VMS, and expectations of aging are significant predictors of supplement use in the model and explain 27 % of the variance. Prior use is the strongest predictor of current use followed by expectations of aging. Ninety-two percent of the independent living women and 94 % of nursing home residents are taking a vitamin, mineral or herbal supplement. Vitamin D is the most frequently reported supplement for both independent living women and nursing home residents. Independent living women report 0 to 16 supplements in a month and 31% use herbals. Seventy-five percent of the independent living women take vitamin D. Seven percent of independent living women are taking vitamin D at or above the Tolerable Upper Intake Level recommended by the Food and Nutrition Board. Health care and food and nutritional professionals should be aware of overuse and high-dose use of supplements. Findings suggest expectations of aging may be an important consideration to understand older women’s health behavior.