Not sure why people think elderly stay in doors more. Elderly usually retire and spend much more time outdoors than those in the middle of life working 8 hours a day. However it is true that elderly absorb at a slower rate and someone already on their death bed and unable to walk would spend more time indoors. Those people are usually given vitamin d supplements though as when you are already sick doctors know you will be deficient and recommend vitamin D.
> An increasing number of older, community-dwelling adults have functional impairments that prevent them from leaving their homes…In total, 5.6% of the elderly, community-dwelling Medicare population (approximately 2 million people) were completely or mostly homebound in 2011.
> Older adults are the least active segment of our population, and are likely to spend less time outdoors than other age groups…One study in a large US national sample found that leisure time [physical activity] was related to higher Vitamin D levels in older adults [43]. Vitamin D deficiency is related to many chronic conditions including cancer, heart disease and bone health [36]. If older adults spent more time outdoors they may be more active and benefit from a healthy dose of Vitamin D.
