I spent 4 weeks in hospital with covid pneumonia.  I was admitted on the 1st August on to a covid ward and my Requirements for supplementary oxygen continued to increase. After 10 days I was transferred to icu. Oxygen requirements continued to increase and they wanted to put me on a ventilator.  I am known to be B12 deficient (I need a monthly injection which was overdue) When they finally gave me my B12 injection my O2 sats started to improve overnight and ventilation was never mentioned again. I was discharged home on the 24th. When I had my next B12 injection at the doctors my O2 sats jumped from 90 to 94 overnight. I now have b12 every 2 weeks.