Same here. Old people are less likely to get enough sunlight [0]. And old people are more likely to have severe COVID-19 symptoms.

Similar story with ibuprofen and COVID-19 [1]. Researchers found a link between the two. But older people are also more likely to take ibuprofen.

[0] https://health.clevelandclinic.org/some-sunlight-may-benefit... [1] https://www.wired.com/story/the-ibuprofen-debate-reveals-the...