Close Banner Integrative Health Research Shows Vitamin D Enhances Cancer Treatment Outcomes Author: Morgan Chamberlain March 12, 2026 Former mbg Editor By Morgan Chamberlain Former mbg Editor Morgan Chamberlain is mindbodygreen's former supplement editor. She graduated from Syracuse University with a Bachelor of Science degree in magazine journalism and a minor in nutrition. Image by McKinsey Jordan / Stocksy March 12, 2026 While any single vitamin can't cure all types of ailments and diseases, there's one nutrient that has been shown to deliver incredible support for immune function time and time again: vitamin D.  In a study published by Cancer (a peer-reviewed journal from the American Cancer Society), researchers discovered that sufficient vitamin D levels helped skin cancer patients enhance the results of their immunotherapy treatment —and, in some cases, even extend their life span. How vitamin D status affects cancer treatment Researchers analyzed vitamin D status of 200 advanced melanoma patients receiving anti-PD-1 immunotherapy (a type of drug that supports the body's immune system in slowing, stopping, and killing cancer cells) as their first-line treatment.  Participants' serum vitamin D levels were measured before receiving immunotherapy and every 12 weeks during treatment. Here's what the study found. Response rate (the percentage of patients that saw their cancer shrink or disappear during treatment) was: 36% in the group with  low vitamin D levels  throughout the study 56% in the group that had healthy vitamin D status at baseline or achieved healthy levels during treatment Progression-free survival (the length of time after treatment initiation that a patient's cancer did not progress) was: 5.75 months for the group with low vitamin D status 11.25 months for the group that achieved healthy vitamin D levels before or during treatment vitamin D3 potency+ Optimized vitamin D3 with absorption technology for whole-body health* ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ (199) Shop now Shop now Overall survival was: 27 months for the group with low vitamin D levels 31.5 months for the group that reached healthy vitamin D levels before or during treatment Researchers concluded that healthy vitamin D levels should be maintained in advanced melanoma patients that are undergoing anti-PD-1 immunotherapy in order to optimize treatment outcomes. RELATED READ:  The 7 Best Vitamin D Supplements Of 2026 The takeaway As demonstrated by this study, vitamin D is a vital nutrient for optimizing immune health and function.  Since food sources and sunlight aren't sufficient sources of vitamin D for the majority of people (you read more about why that is here ), the most efficient and effective way to achieve and sustain healthy vitamin D status is with daily vitamin D supplementation .  vitamin D3 potency+ Optimized vitamin D3 with absorption technology for whole-body health* ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ (199) Shop now Shop now ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ( 199 ) Shop now Shop now