Avoidance mediated the effect of uncertainty on psychological well-being for the high-risk pregnant women in this sample. The results of the study may help perinatal nurses to better understand how high-risk pregnancy affects these women.

The number of individuals aged 65 and older is expected to more than double from 2012 to 2060. The role of vitamin D in the prevention and treatment of diseases associated with aging has not been well studied. Traditionally, the role of vitamin D focused on the maintenance of skeletal health in the older adult. With the discovery of vitamin D receptors in the nervous, cardiovascular and endocrine systems, the role of vitamin D and its impact on these systems has become an important area of research. Older adults are at risk for lower levels of vitamin D as a result of decreased cutaneous synthesis and dietary intake of vitamin D. Epidemiologic evidence indicates an association between low levels of vitamin D and diseases associated with aging such as cognitive decline, depression, osteoporosis, cardiovascular disease, hypertension, type 2 diabetes, and cancer. Clinical trials to determine the benefit of vitamin D supplementation in preventing and treating such diseases are in progress. This paper highlights current evidence regarding the role that vitamin D may play in diseases associated with aging and addresses the need for well-designed randomized trials to examine its benefit on health outcomes in the older adult.

Oxidative stress occurs when there is an imbalance between free radical production and antioxidant capacity. This may be due to increased free radical formation in the body and/or loss of normal antioxidant defenses. Oxidative stress has been associated with the development of cardiovascular disease. The role of antioxidants in the primary and secondary prevention of coronary heart disease is currently under study. Although epidemiologic evidence indicates that antioxidants may decrease cardiovascular risk, clinical trial data are not conclusive. Information regarding the use and benefits of antioxidants in persons with diabetes is limited. Persons with diabetes may be more prone to oxidative stress because hyperglycemia depletes natural antioxidants and facilitates the production of free radicals. In addition, other factors such as homocysteine, insulin resistance, and aging may be contributory. This article highlights landmark clinical trials that have examined the cardioprotective effect of antioxidants. Because these trials have not been designed to study persons with diabetes, and clinical trial data for this group are not available, correlational studies are also presented. Finally, the concept of oxidative stress, the antioxidant and pro-oxidant factors that may contribute to oxidative stress, and the consequences of oxidative stress in persons with type 2 diabetes are presented. Key words: antioxidants, clinical trials,