TGFB1 and chronic obstructive pulmonary disease: TGF‐β1 also attenuated the expression of vitamin D‐independent defense mediators, consistent with an attenuation of vitamin D‐dependent and vitamin D‐independent host defenses.(309) However, these findings were not borne out by the results of a longitudinal study by Jolliffe and colleagues,(310) who found vitamin D supplementation did not augment circulating 25D levels to the same degree in patients with COPD or asthma as in healthy controls.