Letter: ciclosporin and vedolizumab for steroid‐refractory ulcerative colitis

of endogenous ACE2-Ang 1-7 axis activation. These data suggest that, in addition to the use of angiotensin receptor blockers and/or ACE inhibitors and/or ROCK inhibitors, vitamin D may also be beneficial to increase ACE2 and reduce ROCK activity. Furthermore, a telephone survey of over 100 of our Gitelman's and Bartter's patients, all of whom were from hotspots of the COVID-19 pandemic in Northern Italy, found none of them infected with COVID-19.10 This is significant evidence (95% CI 0%-3% compared to the estimated true COVID-19 prevalence in Northern Italy of 8.7%, 95% CI 8.7%-8.8%, P = 0.004), that increased ACE2 and reduced ROCK activity may have beneficial effects in COVID-19 prevention and/ or treatment. Given the rapidly evolving nature of the COVID-19 pandemic and in consideration of the reported effects of vitamin D on ACE2 and ROCK, vitamin D might also be used to reduce the severity of COVID-19.