Cancer’s power couple — Vitamin D and 1993’s Molecule of the Year

I’ve moved on from fantasy novels to now writing gossip columns.

Admittedly a stretch, but still technically true if you consider the pairing of vitamin D supplementation and p53 (1993’s Molecule of the Year), a celebrity couple.

As to what is p53, well I’m not one for reinventing the wheel so instead I’ll give you the words of the late great, Daniel E. Koshland Jr. …

“Some molecules are good guys, some are bad guys, and some become bad because they fail in their functions. The molecule p53 is a good guy when it is functioning correctly … It is a tumor suppressor in that it halts abnormal growth in normal cells and thus prevents cancer. However, a small change in p53, a mutation of one of its 393 amino acids, can eliminate the surveillance capability of the protein and allow a cancer to grow. So a mutated p53 is frequently as bad as no p53 at all.”

TLDR: p53 is good, but really only when it’s working

The bad news is that it’s thought that p53 is mutated in 50% of cancerous tumours, the good news is that p53 is not alone in the fight. There is evidence that suggests that when p53 is mutated, the positive effect of vitamin D supplementation can actually increase.

Kanno et al. 2023 conducted a post-hoc analysis on the effect of vitamin D supplementation on cancer patients that tested positive for markers indicating a p53 mutation. In doing so, they found a significant decrease in death or relapse in patients with digestive tract cancer. Interestingly, the benefit of supplementation was not significant in patients where the markers indicated no p53 mutation.

However, it’s important to bear in mind that this is not the be all and end all of studies on vitamin D and p53 as there were a few limitations.

My explanation of the study was rather clunky as I had to specify that the analysis was post-hoc, meaning that the analysis was done in hindsight. Quite likely because the original analysis didn’t product significant results. That doesn’t mean that there’s anything dodgy about the analysis, just that study likely wasn’t designed to directly answer the question.

Furthermore, you may have noticed I didn’t say patients with or without the p53 mutation, but instead patients that tested positive or negative for markers indicating a p53 mutation. That’s because mutations of the p53 gene were not directly sequenced. Again that doesn’t mean the tests were wrong, just that they could not completely prove the presence or absence of a p53 mutation.

With these limitations, you could make the point that the study raises more questions than answers. But I’d say those questions are good questions to ask and in need of answering. After all, sometimes the best breakthroughs come not from the right answer, but from the right question! It would incredible news if we definitively found that vitamin D supplementation siginifcantly decreased death and relapse in cancer patients with p53 mutations. Particularly considering that is estimated to be 50% of cancers!