適度的陽光照射不僅有助於人體維生素D的生 成，對改善骨骼健康、情緒認知有正面的影響 外，更可調節褪黑激素的分泌而調控人體生理 時鐘，有益於改善老人的睡眠品質，增加身 體活動和社交的參與度。但長時間曝露在陽光 下，對人體皮膚、眼睛及免疫系統的傷害也是 不可忽視的。不過因許多研究均顯示，老人接 觸陽光的時間普遍不足，特別是機構老人的活 動型態多以室內為主，清醒時間多是坐著發呆 或是坐在電視前打瞌睡。再加上健康因素、環 境設計、個人喜好與機構活動設計，都會使 得機構老人接觸陽光的時間少於一般可自我照 顧的長者。因此建議除了從飲食及營養補充品 中適當補充維生素D外，也可以在做好適當的 防曬措施下，讓老人每週進行戶外活動至少五 次，每天20–30 分鐘。長期照護機構在硬體設 備亦建議能增加老人接觸陽光的方便性與可近 性外，也可將部分的活動設計在戶外舉行，讓 機構的老人有適當接觸陽光的機會。

Appropriate exposure to sunlight not only contributes to the production of vitamin D, which has been associated with enhanced bone health, mood, and cognitive functions, but also regulates the secretion of melatonin, which has been associated with the mediation of circadian rhythms, improved sleep quality, and optimized physical and social activity in the elderly. However, damage to the skin, eyes, and immune system has also been widely associated with long-term exposure to sunlight. Several studies have shown that many elderly, especially those that reside in institutions, do not receive sufficient sunlight exposure. Institutionalized elderly tend to participate in indoor activities and spend significant periods of time alone and asleep in front of the television. Furthermore, factors such as poor health, environmental design, indoor/outdoor preference, and activity design may impact the access of institutionalized elderly to sunlight more than their non-institutionalized peers. Therefore, we suggest that in addition to obtaining sufficient levels of vitamin D from their diet and from supplements, the elderly should perform outdoor activities for 20-30 minutes a day for five days each week. Furthermore, we suggest that the environment of the care facility should be made be more accessible and that some activities should be held outdoors.