One possibility. But the original study carefully controlled for exercise and lifestyle factors. To corroborative the causal relationship, we also have extensiv

One possibility. But the original study carefully controlled for exercise and lifestyle factors. To corroborative the causal relationship, we also have extensive experimental evidence where UV and/or bright light on skin/eyes directly improves systematic biomarkers associated with longevity[1][2][3]. These improvements occurs independent of vitamin D synthesis.[4] [1]https://www.sciencedirect.com/science/article/pii/S0022202X15368780 https://www.sciencedirect.com/science/article/pii/S0022202X1... [2]https://www.sciencedirect.com/science/article/abs/pii/S037851221500674X https://www.sciencedirect.com/science/article/abs/pii/S03785... [3]https://www.hindawi.com/journals/bmri/2016/1934518/ https://www.hindawi.com/journals/bmri/2016/1934518/ [4]https://academic.oup.com/endo/article/159/5/1992/4931051?login=true https://academic.oup.com/endo/article/159/5/1992/4931051?log...