Fresh air and sunshine benefit people at every stage of life. Those with dementia, even severe-stage disease, are no exception. Try to get your loved outside for a few minutes each day. Even someone who’s bedbound can usually be transferred to a chair and wheeled to a porch or patio. If you can’t manage this yourself, is there a neighbor who could help, or a paid aide who can add it to his or her daily roster of duties? In winter or bad weather, try sitting your loved one in front of a window.

Not convinced it’s worth the effort? Consider these three benefits of “vitamin O” — ones that caregivers can use as much as their loved ones.

1. Being outside boosts mood. Even though a loved one can’t necessarily communicate pleasure, the capacity for pleasure remains. At its most basic, there’s innate pleasure in the change of scenery going from inside to out, in seeing greenery, feeling the warm sun or a light breeze, smelling fresh-cut grass. For people with dementia, who continue to absorb and reflect the prevailing emotional vibe even when they can’t remember specific experiences, the mood-boosting effect of positive experiences can last for hours or days.

2. Being outside lowers stress. Biologically, being in nature has been found to lower blood pressure and pulse rate and to reduce the amount of cortisol, a stress hormone.

3. Being outside boosts immunity. Studies have shown that being outdoors boosts white blood cell counts, and that this effect can last for days.