Can you elaborate on your knowledge in the first graph? I thought I remember reading that scurvy patients recover pretty quickly, and according the the NHS[0], it's about 48 hours to start feeling better and 2 weeks to recovery.
Scurvy is vitamin C deficiency. Vitamin C is water soluble.
Vitamin D is fat soluble. Fat soluble vitamins generally work on a longer, slower time scale. It takes longer to incorporate them into the body and longer to become deficient.
People who are deficient in vitamin C may simply not be getting enough of it in their diet. Because vitamin D can actually be manufactured in the body, it tends to correlate to other underlying issues.
People with other underlying issues tend to require more time to recover from anything, medically speaking. They may even have inherent challenges in absorbing vitamin D properly or using it properly.
I have a genetic disorder that predisposes me to deficiency in all fat soluble vitamins, including vitamin D. I'm sure my firsthand experience with being slow to heal and my body being slow to adequately resolve nutritional deficiencies (on the order of months of supplementation to fix things) is on the fairly extreme side, but most Covid-19 patients in danger of dying from it are elderly and have underlying health issues. So I would expect my experiences to be somewhat similar to their situation.
I'm not a doctor. I'm a former homemaker who spent years homeless.
But based on those stellar credentials, if I am understanding your question correctly, the answer is "both." It is both slower to access and also the reason you can wind up vitamin D toxic in a way that doesn't generally happen with water soluble vitamins.
You can get get too much of water soluble vitamins and they can do bad things to the body, but those bad things aren't described as "toxicity" because you don't build up excessive stores of them in the body like you can with fat soluble vitamins. Off the top of my head, some people who take way too much vitamin C end up harming their dental health by harming the tooth enamel and a certain B vitamin when taken in excess is associated with, iirc, kidney stones.
Rickets is most commonly caused by vitamin D deficiency. I suspect the comment which you replied to made an honest mistake confusing scurvy with rickets.
When I google both scurvy and rickets, my impression is that no such error was made. Materials about scurvy match the remark made above. Materials about rickets do not.
Most people treated for scurvy feel better within 48 hours and make a full recovery within 2 weeks.
Most children with rickets see improvements in about one week.
Skeletal deformities will often improve or disappear over time if rickets is corrected while the child is still young. However, skeletal deformities can become permanent if the disorder isn’t treated during a child’s growth period.
Scurvy is vitamin C deficiency. Vitamin C is water soluble.
Vitamin D is fat soluble. Fat soluble vitamins generally work on a longer, slower time scale. It takes longer to incorporate them into the body and longer to become deficient.
People who are deficient in vitamin C may simply not be getting enough of it in their diet. Because vitamin D can actually be manufactured in the body, it tends to correlate to other underlying issues.
People with other underlying issues tend to require more time to recover from anything, medically speaking. They may even have inherent challenges in absorbing vitamin D properly or using it properly.
I have a genetic disorder that predisposes me to deficiency in all fat soluble vitamins, including vitamin D. I'm sure my firsthand experience with being slow to heal and my body being slow to adequately resolve nutritional deficiencies (on the order of months of supplementation to fix things) is on the fairly extreme side, but most Covid-19 patients in danger of dying from it are elderly and have underlying health issues. So I would expect my experiences to be somewhat similar to their situation.
Does that make sense? Did I answer the question?