Elevated serum vitamin D levels are linked with higher skin cancer risk, finds study
Skin cancer, the most common global malignancy, is linked to ultraviolet (UV)-driven serum 25-hydroxyvitamin D (25(OH)D)synthesis, with its controversial role possibly reflecting cumulative UV exposure. This study aimed to assess the association and causality between 25(OH)D levels and skin cancer risk using the National Health and Nutrition Examination Survey (1999–2018) data and Mendelian randomization (MR) analyses, evaluating 25(OH)D as a screening biomarker.
We integrated data from the National Health and Nutrition Examination Survey (1999–2018; n = 21,357 U.S. adults, including 631 skin cancer cases) with MR analyses using genome-wide association study-derived genetic variants to assess the causal relationship between serum 25(OH)D levels and skin cancer risk.
Higher 25(OH)D levels were associated with increased risks of nonmelanoma skin cancer [odds ratio (OR) (95% confidence interval (CI)) = 2.94 (2.10, 4.20)], melanoma [OR (95% CI) = 2.94 (1.73, 5.28)], and other skin cancers [OR (95% CI) = 2.10 (1.36, 3.36)]. MR analyses supported a causal relationship for nonmelanoma skin cancer [OR (95% CI) = 1.01 (1.00, 1.02)] and melanoma [OR (95% CI) = 1.00 (1.00, 1.01)]. Risks were highest in males, older adults, and individuals with obesity.
People with higher vitamin D levels had nearly 3× the odds of getting skin cancer compared to those with lower levels. Genetic analysis supports a modest causal link—meaning vitamin D might contribute to risk, but the effect is small.Vitamin D is produced in your skin when you’re exposed to UV rays—the primary risk factor for skin cancer. Therefore, high vitamin D probably indicates more sun exposure, which drives the increased risk.
Higher serum 25(OH)D levels are associated with increased skin cancer risk, likely reflecting cumulative UV exposure. Routine monitoring of 25(OH)D, combined with UV exposure management, is recommended for risk stratification in skin cancer screening, particularly among high-risk groups. Validation in multiethnic cohorts is needed to confirm these findings.
Reference:
Meng J, Du R, Li P, Lyu J. Association between Serum 25-Hydroxyvitamin D Levels and Skin Cancer Risk: An Observational Study Based on NHANES and Mendelian Randomization Analysis. Cancer Screen Prev. 2025;4(2):89-97. doi: 10.14218/CSP.2025.00010.
