Here’s the study:
Castillo, Marta Entrenas, et al. “Effect of Calcifediol Treatment and best Available Therapy versus best Available Therapy on Intensive Care Unit Admission and Mortality Among Patients Hospitalized for COVID-19: A Pilot Randomized Clinical study.” The Journal of Steroid Biochemistry and Molecular Biology (2020): 105751.
This is a peer-reviewed, randomized, placebo-controlled study of hospitalized Covid-19 patients. So it is an “RCT”. This is the type of study that the press and various online critics demand. Some persons unwisely reject all other types of studies, which is not reasonable or scientific. But this is the type of study we’ve been waiting for, to confirm the other 20 studies here.
The study took place in a university hospital setting: Reina Sofia University Hospital, in Cordoba, Spain. The 76 patients were all hospitalized for confirmed cases of Covid-19. So these are not the mild to moderate, stay-at-home types of patients. The intervention group was 50 patients and the control group was 26 patients.
The intervention group received calcifediol, which is a type of vitamin D found in the blood. It is not the usual type of vitamin D found in supplements. Calcifediol is also known as 25(OH)D or 25-hydroxyvitamin D. The reason for giving this type of vitamin D is that the usual supplement type takes about 7 days to turn into calcifediol, so by giving patients calcifediol itself, you get the good effects without having to wait 7 or so days [per Wikipedia].
The dosage of calcifediol converts to IU (international units at a ratio of 200 to 1). So 10 micrograms of calcifediol is 2000 IU of vitamin D, whereas 10 micrograms of vitamin D3 is 400 IU (a 40:1 ratio). The dosage given to the patients, in IUs, was:
Day one: 106,400 IU of vitamin D
Day three: 53,200 IU
Day seven: 53,200 IU
Once-a-week thereafter: 53,200 IU
This is equivalent to about 30,000 IU per day for the first week, and 7,600 IU per day thereafter. Yes, you can take your vitamin D supplement in a once-a-week dosage, instead of daily.
The results were astounding (and highly statistically significant). “Of 50 patients treated with calcifediol, one required admission to the ICU (2%), while of 26 untreated patients, 13 required admission (50%)”. Would you rather have a 50% risk of needing ICU care, or a 2% risk? Almost all hospitalized Covid-19 patients who die, die in the ICU. That is where the most severe cases are sent. So this study shows that vitamin D reduces the severity of Covid-19.
In the statistically adjusted results, vitamin D reduced the odds of ICU admission by 97%. The RR (risk reduction) for ICU admission in hospitalized Covid-19 patients was 0.03 as compared to the control, which is given the value of 1.00. The odds of Covid-19 patients in general, as compared to hospitalized Covid-19 patients, needing ICU care would be even lower, as you would first need to be hospitalized to enter that risk ratio, and vitamin D has been shown by other studies to reduce risk of hospitalization. So taking a vitamin D supplement has tremendous benefits.
For mortality, 2 patients in the control group died; no patients in the vitamin D group died. There were not enough deaths to make the results statistically significant. But hospitalized patients don’t usually die from Covid-19, unless they are in the ICU. We would expect the reduction in death to be of a similar order of magnitude to the reduction in need for ICU care. Also, if you need mechanical ventilation, that is ICU care. So the vitamin D would seem to reduce risk of ventilation as well.
There is now enough evidence for treatment with calcifediol, also known as 25(OH)D, to be STANDARD CARE for hospitalized patients with Covid-19. There is enough evidence for vitamin D supplementation to be recommended to everyone at risk of vitamin D, especially those at high risk. And since the elderly often have difficulty absorbing vitamin D, they should receive a higher dosage.
Here’s an article reviewing the study by Chris Masterjohn, Ph.D.: Finally Confirmed! Vitamin D Nearly Abolishes ICU Risk in COVID-19