I laughed when the Dr in the article recommended sunscreen plus blood pressure pills. The confidence in narrow pharmaceutical interventions is absurd when we keep realizing that we don't understand how all the systems in the body are interconnected.
However, subsequently a meta-analysis (including that same paper) was published that found:
"Vitamin D [supplementation] was associated with significant reduction of cancer-related mortality compared with placebo [...]. Compared with placebo, Vitamin D was not associated with significant reduction of cancer incidence [...]".
https://www.tandfonline.com/doi/pdf/10.1080/20009666.2019.17...