The author’s qualifications to the side, This definitely happened, and patients did do better outside than in. It’s a puzzle as to why:
The germicidal effect of light above 280nm (UVC) is well documented (degrades thymine bonds in DNA/RNA). But this is not a component in ground level sunlight as it’s filtered out by the atmosphere. Yes, UVB and A are also somewhat germicidal — but not nearly as effectively
A vitamin D deficiency will depress the immune system, and one of the ways we get Vitamin D is from UVA exposure to our skin, but I have to wonder how much skin is exposed when a patient is in a bed with blankets.
In children, an extreme Vitamin D deficiency caused rickets (a bone softening and skeletal deformation), first referenced in the 1630s. Prevention of this with cod liver oil goes back at least as far back as the American Civil War (I’ve seen Civil War era cod liver oil bottles). I haven’t see any comments of this oil being given to the sick in 1917, but maybe?
My guess is that the difference in outcomes was a matter of air circulation reducing viral and, more importantly, bacterial load. If someone has the flu, you do NOT want them in a closed ward with someone with bacterial pneumonia —remember they had no antibiotics at the time — and it seems that most people who ‘died of the flu’ actually died of pneumonia or other opportunistic infections.
BTW/FWIW, vitamin D deficiency is also associated with greater susceptibility to pneumonia (children with rickets also often had alveolar and bronchial damage). Given that COVID19 seems to directly attack the lungs, I’ve upped my daily vitamin D intake to the recommended maximum (4000IU/day). If you’re an over-60 like me, you might consider doing the same. NOTE: Vitamin D in extreme doses can be toxic (primarily hypercalcemia, early symptoms of which include nausea, vomiting, diarrhea, constipation,weakness, but it can progress to kidney damage). Do not poison yourself based on something you read on the Internet! Also, I am NOT a medical professional (closest I ever got was writing statistical analysis code for a drug epidemiology firm — which does NOT count). Go google the max dose yourself — and please be careful!
