Vitamin D and Magical Thinking

I saw an article this morning on Vitamin D and Large B Cell Lymphoma, and I had to share and comment. Not necessarily about the research itself -- it doesn't have much of anything to do with anyone reading this blog -- but because of the reminders it gave me about a bunch of issues related to my experience as a cancer patient.

The article is called "Vitamin D Insufficiency and Clinical Outcomes with Chimeric Antigen Receptor T-Cell Therapy in Large B-cell Lymphoma: Vitamin D insufficiency and CAR-T in LBCL," and will appear in the journal Transplantation and Cellular Therapy. I won't get too much into the details, but here's the study:

(To be clear here -- this is NOT a study involving Follicular Lymphoma patients.)

The researchers (there are a lot of them) wanted to know if blood levels of Vitamin D had an effect on CAR-T in LBCL patients. This is an observational study, not a clinical trial. In other words, they looked at a bunch of patients in one cancer center, rather than developing strict criteria for who could be a part of a study. They ultimately looked at 111 patients with relapsed or refractory LBCL who were about to be treated with CAR-T. They divided the patients into two groups -- one for patients with low vitamin D levels, and the other for patients with normal levels.

They found that, after 100 days, the Response Rate was 55% for the low Vitamin D patients, and 76% for the normal Vitamin D patients. After 2 years, the survival was 41% (low) and 71% (normal). They also found that the T cells that were taken from patients and then changed and put back into the patients were more viable for the patients who had normal Vitamin D levels. In other words, the cells lasted longer and worked better when Vitamin D levels were normal.

The authors were very clear that this was a very narrow study, looking at patients in one cancer center, and the idea that Vitamin D might help LBCL patients getting CAR-T needs to be studied more. Interesting study, but we can't get too excited about it.

That said, I'm excited about it. And that's kind of a problem.

I've been interested in Vitamin D and its relationship to cancer for a long time. There really isn't any definitive research that says Vitamin D will help cancer patients -- and certainly no research that says it will cure cancer. But it seems like there are enough small, focused research studies that, if you put them all together, like pieces of a puzzle, they suggest that there is a connection between the two.

And here's why it's a problem that I think that way.

It's bad science. And I value science and what it tells us about cancer treatments. But a whole bunch of studies that say "maybe, kind of" isn't the same as one study that says "Yes!"

All of this just reminds me of what makes it hard to be a cancer patient. It's a constant battle between the head and the heart. Science tells our heads that something is or isn't true, and our rational sides can understand that. But then there's the heart -- the emotional side -- that wants something easy and safe to be true. There's always a little bit of magical thinking in all of us. A teaspoon of turmeric, or a broccoli sprout sandwich, or 20 minutes on a trampoline every day will keep the cancer away. If only it was that easy. But I'm pretty sure it's not. 

And that's my complicated history with Vitamin D. I've been taking it for years. I've read enough about how Vitamin D might help a whole bunch of health issues that I'm too invested to think it won't help. This is called a "sunk cost fallacy." People refuse to change their minds about something because they've spent so much time and effort believing in it that they don't want to give up on it.

And since I've been taking Vitamin D for about as long as I have gone without treatment, it's easy to connect the two. (That's another fallacy -- correlation doesn't equal causation. I also had a big change happen at work at the same time. By that logic, I could say the change in my job is what caused my cancer to go away. I can guarantee that wasn't the case.)

So for me, the big lesson here is not to tell you to give up on magical thinking, and only do things that are backed up by science. That would be a little hypocritical. 

The lesson is that we need to choose which things we think magically about. I have real problems with patients who decide not to go with conventional treatment like chemotherapy or immunotherapy, and instead think that massive doses of vitamin D or bowls of broccoli will cure them. That strikes me as foolish, when there is science to back up that it could be effective in keeping you alive.

But going through chemo, and then switching to a vegetarian diet, or taking fish oil and Vitamin D, or exercising 60 minutes a day? Sure. None of those "extra" things will harm you, and most will help you stay healthier, even if they don't have any effect on your cancer. 

And maybe more importantly, apart from the long-term benefits that they might have, sometimes we just need something magical to get us through the day. Maybe it's a broccoli sprout sandwich. Maybe it's calling yourself a "cancer warrior." Maybe it's saying a prayer to St. Peregrine. There's no way that science will tell you it works. But maybe it helps us be at peace, even for a little while.

So I'm going to keep taking my Vitamin D. Please don't ask me what my levels are, or how much I take each day. I'm not here to give you medical advice. Ask your doctor if that's something that might help you.

But also trust that some things are OK, even if your doctor, or some other rational person who hasn't lived your experience, tells you otherwise.