It is my opinion that the higher cancer incidence found in those with increased serum vitamin D levels was due in part to confounding by health oriented behavior that was no accounted for in adjustments for relative risk, including (1)
decreased intake of vitamin K2 due to avoidance of saturated fat and particularly to avoidance of cheese (2) increased intake of N - 6 fats in accordance with USDA recommendations thereby increasing risk of prostate cancer (see PMID 20693267) and (3) increased intake of
supplements such as
folic acid which increases prostate cancer risk (PMID 19276452)