Lai GY, et al. - Within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, researchers sought to ascertain the association of circulating 25-hydroxyvitamin D [25(OH)D] concentrations with liver cancer and chronic liver disease (CLD). Findings suggest a possible preventive role for vitamin D against liver cancer and CLD. However, the importance of the liver for vitamin D metabolism and the lack of information about underlying liver disease makes reverse causality a concern.

Methods

• 25(OH)D was measured in baseline serum of 202 incident liver cancer cases and 225 CLD deaths that occurred during nearly 25 years of follow-up, and 427 controls in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study.
• Using unconditional logistic regression, resaerchers estimated ORs and 95% confidence intervals (CIs).
• Predetermined clinically defined cut-points, and season-specific and season-standardized quartiles were examined.

Results

• Higher risk of liver cancer (<25 nmol/L vs ≥50 nmol/L: 1.98; 95% CI, 1.22–3.20; P_trend across categories = 0.003) and CLD mortality (1.93; 95% CI, 1.23–3.03; P_trend=0.006) were noted in association with low serum 25(OH)D concentrations in models adjusted for age and date of blood draw.
• The association remained statistically significant for liver cancer (1.91; 95% CI, 1.16–3.15; P_trend=0.008), but was somewhat reduced for CLD mortality (1.67; 95% CI, 1.02–2.75; P_trend=0.05) after additional adjustment for body mass index, diabetes, smoking, and other potential confounders.
• For analyses using season-specific and season-standardized quartiles, and after excluding participants with diabetes, or hepatitis B or C, the associations were similar.