Umbrella Review on the Relationship between Vitamin D Levels and Cancer

Area of Science:

• Nutritional Biochemistry
• Oncology
• Public Health

Background:

• Cancer represents a significant global health challenge.
• Vitamin D is implicated in cancer development and progression through various biological pathways.
• Existing research reviews have not comprehensively addressed the link between vitamin D and cancer incidence or mortality.

Purpose of the Study:

• To synthesize current evidence on the association between vitamin D and cancer.
• To examine the relationship between vitamin D levels and the incidence and mortality of five common cancers: breast, colorectal, lung, pancreatic, and prostate.

Main Methods:

• An umbrella review methodology was employed.
• Systematic reviews investigating vitamin D's association with cancer incidence or mortality were systematically searched and analyzed.
• Focus was on circulating 25(OH)D levels as the measure of vitamin D status.

Main Results:

• Consistent inverse correlations were observed between vitamin D levels (25(OH)D) and mortality across all five studied cancer types.
• Evidence suggests a potential reduction in cancer incidence for breast, colorectal, lung, and pancreatic cancers with higher vitamin D levels.
• The association between vitamin D and prostate cancer incidence requires further investigation.

Conclusions:

• While observational studies dominate, indicating inverse correlations between vitamin D and cancer mortality/incidence, definitive causal links cannot be established.
• Methodological heterogeneity across reviews and individual studies presents challenges in interpretation.
• Despite limitations, the findings highlight a significant inverse relationship between vitamin D status and cancer outcomes.