Background: By 2030, it is estimated that 20 percent of the U.S. population will be 65 years or older. In conjunction with an aging population comes an increase in morbidity and disability. This could potentially have a negative impact on health care costs and quality of life for these individuals. For older patients, one method of preventing or delaying the onset of disabilities is to identify factors that may contribute to these problems. One of these factors is poor nutritional status, which is thought to lead to a decline in physical functioning. However, there are no studies that establish a causal effect between nutritional status and disability in older patients. Bartali and colleagues assessed whether low concentrations of nutrients in older patients could predict the development and course of a disability.

The Study: Women who were 65 and older and living in the community were randomly selected. The participants were screened and asked to self-report difficulties in mobility, upper extremity function, higher-functioning household management, and self-care. Women who had deficiencies in two or more domains but were able to perform daily activities were enrolled in the study. A standardized interview that included questions about the ability to perform routine activities needed for living (e.g., bathing, dressing, and feeding themselves) was done at the beginning of the study and repeated every six months for three years. A physical examination was performed, as were blood tests to assess levels of micronutrients such as carotenoids, retinol, 25-hydroxyvitamin D, vitamins B₆ and B₁₂, folate, selenium, and zinc.

Results: The study population included 643 women with a mean age of 77.3 years. The authors found that 32.3 percent of the women who could perform routine daily activities at baseline were incapable of performing them by the end of the three-year study. Participants with micronutrient levels in the upper quartiles were compared with those in the lowest quartile. Those in the lowest quartile for vitamin B₆ were significantly more likely to develop disabilities in their activities of daily living compared with the other quartiles. This also was true for vitamin B₁₂ and selenium levels. The lowest levels of the remaining micronutrients, however, did not have a significant impact on disability.

Conclusion: Low levels of selenium and vitamins B₆ and B₁₂ can predict future disabilities in activities of daily living in women who are 65 years and older. Although this study does not suggest that nutritional supplementation is beneficial, these factors should be considered when developing a disability prevention strategy.