Correlation of objectively measured light exposure and serum vitamin D in men aged over 60 years.

Diminished vitamin D is common among older individuals. Sunlight contributes more to vitamin D synthesis than diet or supplementation. This study examined associations between objectively measured light exposure, vitamin D serum levels, and bone biomarkers in 100 men aged over 60 years.

Optimism predicts positive health in repatriated prisoners of war.

"Positive health," defined as a state beyond the mere absence of disease, was used as a model to examine factors for enhancing health despite extreme trauma. The study examined the United States' longest detained American prisoners of war, those held in Vietnam in the 1960s through early 1970s. Positive health was measured using a physical and a psychological composite score for each individual, based on 9 physical and 9 psychological variables.

Physical activity, sleep, and C-reactive protein as markers of positive health in resilient older men.

This study explored whether physical activity and sleep, combined with the biomarker C-reactive protein, indexed positive health in older men. Many were former prisoners of war, with most remaining psychologically resilient and free of any psychiatric diagnoses. Activity and sleep were recorded through actigraphy in 120 veterans (86 resilient and 34 nonresilient) for 7 days.

Optimism predicts resilience in repatriated prisoners of war: a 37-year longitudinal study.

Resilience, exhibiting intact psychological functioning despite exposure to trauma, is one perspective as to why some people who are exposed to trauma do not develop symptoms. This study examines the prisoner of war experience to expand our understanding of this phenomenon in extreme cases of trauma such as prolonged captivity, malnourishment, and physical and psychological torture. The study examined the United States' longest detained American prisoners of war, those held in Vietnam in the 1960s through early 1970s.