Serum 25-hydroxy vitamin D and prostate cancer risk in a large nested case-control study

Area of Science:

• Nutritional epidemiology
• Prostate cancer research
• Vitamin D metabolism

Background:

• Experimental studies suggest vitamin D inhibits prostate cancer.
• Epidemiologic data on vitamin D and prostate cancer risk are inconsistent.
• Some studies indicate nonsignificant positive associations between vitamin D and prostate cancer.

Purpose of the Study:

• To investigate the association between serum 25-hydroxy vitamin D [25(OH)D] levels and prostate cancer risk.
• To examine this relationship in a large cohort of Finnish men.

Main Methods:

• Nested case-control study within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study.
• 1,000 prostate cancer cases were matched to 1,000 controls based on age and blood collection date.
• Conditional multivariate logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

Main Results:

• Men with higher serum 25(OH)D levels showed a statistically significant increased risk of prostate cancer (P(trend) = 0.01).
• The risk was particularly elevated for aggressive prostate cancer and in subgroups with higher physical activity, cholesterol, alpha-tocopherol, calcium, or vitamin D intake.
• The fifth quintile of serum 25(OH)D concentration was associated with a 56% increased risk of prostate cancer (OR = 1.56; 95% CI, 1.15-2.12).

Conclusions:

• Higher blood levels of vitamin D are associated with an increased risk of developing prostate cancer.
• Findings suggest caution regarding recommendations for high-dose vitamin D supplementation and elevated population blood level targets.
• Further research is needed to clarify the complex role of vitamin D in prostate cancer.