JPD - Your question is complex. It would take me pages to answer it in sufficient detail. However - it is important to note that antibodies alone are not how our bodies defend against foreign pathogens such as Covid. There is an interplay between various immune cells and their protein products in both defending against a virus initially (first time) and in protecting against future exposure later. Most of this occurs by lymphocytes which work together to defeat the pathogen.
Antibodies are produced by B-cell lymphocytes. They get their marching orders from helper T-cells. And this is important to understand. B-cells are activated to produce antibodies by these helper T-cells. They work together. And T-cells are activated by vitamin D. (and so are B-cells! https://pubmed.ncbi.nlm.nih.gov/24761763/).
Antibodies are produced as a first line of defense against a virus (and related) by physically binding to the virus thereby inactivating it. This causes a notification to the rest of the immune system (T-cells mostly) that bad things are happening leading to recruiting of those cells which actually destroys the virus (gone from the body). Below are summary articles describing this interplay.
It is important to note that adequate vitamin D is vital to the proper function of this complex system. The amount of antibody produced in response to either the virus or vaccine is NOT correlated with immunity. More antibody does not mean more immunity. This is important to understand. Antibody production is in response to exposure - but if your T-cells get busy fast (i.e. vitamin D activated!!!!!) - B-cells won't need to produce much antibody - the job is done. Lasting immunity occurs because memory cells which have the antibody information are left behind and in small numbers. Upon re-exposure to the virus, quick ramp up of T-cells (and antibodies) can occur.
What gives you immunity to Covid is the response balance of your immune system. Antibodies alone are only part of this. There are several papers recently published that show antibody production is inversely correlated with vitamin D level - meaning that the more vitamin D you have the less antibody production. And this makes sense when you think about it in terms of what an antibody does and what a T-cell does. If my body keeps producing more and more antibody in response to a virus, it actually may mean my immune system is weak - it can't clear the virus (i.e. T-cells) - so more antibodies are produced to bind to the virus and inactivate it. And all this binding to a foreign substance leads to more and more inflammation leading to a whole new set of problems until the virus is cleared and other T-cells (helper T-cells) tell the immune system it's o.k. now to stand down - thereby reducing inflammation.
I can't stress ENOUGH the importance for EVERYONE to get their vitamin D level checked and then raise it above 55 ng/ml in order to maximize your natural defense against Covid (or any flu, colds, etc.). It will keep your body from over-reacting to a virus as well as quickly destroying it. Getting vaccinated is not enough. In fact, you may be reading how highly vaccinated countries (Israel) are having a tough time with Covid. All vaccination does is give the body a head start by triggering an antibody response (i.e. the marching orders). If T-cells can't activate fast enough to the accumulating viral-antibody bindings, then inflammation keeps rising - even to the point of breakthrough (run away inflammation leading to hospitalization or worse).
There is no case documented - none that I can find of a patient dying of Covid who also had high vitamin D - none. This is very interesting to know.
I hope this helps explain a very complex system.
"Antibodies may not be the only protection
Does it really matter how high an antibody level I have? Immunologist Dan Barouch of Harvard Medical School says probably not and points to a study being done at the school.
“In this study, we define the role of antibodies versus T cells in protection against COVID-19 in monkeys,” Barouch said. “We report that a relatively low antibody titer [the concentration of antibodies in the blood] is needed for protection.”
Another article, this one on the Children’s Hospital of Philadelphia website, agrees with Barouch’s assessment. It points to the fact that scientists have not yet identified a “correlate of protection” for the COVID-19 vaccines. This is “a quantity of specific antibodies above which a person is protected against an infection and below which protection is uncertain.” It also points to evidence that some types of T-cells can affect a person’s course of a SARS-CoV-2 infection. And it agrees that “getting an antibody test to see if the vaccine worked is not as helpful as it would appear.”
" ..... vitamin deficit is able to cause imbalance of the immune system and the supplementation of pharmacological doses of 250-500 mcg/day [16,17] of vitamin D can be useful in the treatment of viral infections by influenza or coronavirus. Thus, it is reinforced that vitamin D should be used by health professionals through pharmacological doses to prevent vitamin D deficiency and avoid viral infectious risks [6,8], therefore, it is possible to conclude that daily pharmacological doses have the benefit of improving symptoms of viral respiratory infections [9,14]."
A final point - vitamin D is not magic. Our immune system can be weak for other reasons (leukemia) and fail to respond. All a vaccine does is arm the immune system with an early warning device. Without vitamin D, however, it's like a gun without bullets.
Dr. Fauci takes 6,000 IU's of vitamin D3 a day. Why doesn't he tell everybody this from his high perch?