In my previous post on the covid pandemic I mentioned that the body’s main defence against viruses is T-cells, not antibodies, and that the only reason we test for antibodies instead in clinicial practice is because it is easier and cheaper. I also ventured a hypothesis that the levels of population immunity are much higher than is being found in the antibody tests, and that this is because lots of people who don’t have antibodies do have covid specific T-cells. It turns out that this hypothesis is supported by new evidence.
A new study has just been published in JAMA (the Journal of the American Medical Association) that seeks to answer this question definitively. This subject has been somewhat controversial, because observational studies have tended to show a positive effect, while randomised clinical trials have failed to show any effect. Usually you would trust the trial data more than the observational data, but these trials were all relatively short (generally a year or less), had relatively small study groups, and often used quite low doses of vitamin D.
Ok, I want to preface this article by stating that it is entirely anecdotal and based on my experience working as a doctor in the emergency room of one of the big hospitals in Stockholm, Sweden, and of living as a citizen in Sweden. As many people know, Sweden is perhaps the country that has taken the most relaxed attitude of any towards the covid pandemic. Unlike other countries, Sweden never went in to complete lockdown. Non-essential businesses have remained open, people have continued to go to cafés and restaurants, children have remained in school, and very few people have bothered with face masks in public.
This question has actually been pretty thoroughly researched, so it should be possible to come up with a conclusive answer. A systematic review and meta-analysis of the collected data was published in the British Journal of Medicine in 2017. The review was funded by the National Institutes of Health (NIH). No companies standing to benefit from the sale of vitamin D supplements were involved in funding the study and none of the authors had financial ties to any such companies. That makes me quite prone to trust the data.
If you take blood pressure medications you probably have some interest in following your own blood pressure. But what many people don’t know is what target blood pressure they should be aiming for. If your blood pressure after treatment is 140/85, say, is that good or bad?
Ok, it’s a silly question I admit. As any physician, and anyone else who thinks about it for a few seconds knows, there is no such thing as saving lives. You can only postpone death. So a more nuanced question is required: “Do statins postpone death?”. My mother sure thinks they do, since she’s been popping an atorvastatin a day for the last couple of years on her GP’s recommendation. Of course, the question gets more complicated when you consider two things: