There is a study showing issues with Head and Neck Cancer, also, on the NCI site:

http://www.cancer.gov/clinicaltrials/results/summary/2005/vitamine0805


CG to husband - SCC Tonsil T1N2M0 HPV+ Never Smoker
First symptoms 7/2010, DX 12/2010
TX 40 IRMT (1.8 gy) + 10 Cetuximab
PET Scans 6/2011 + 3/2012 clear, 5 year physical exam clear; chest CT's clear of cancer. On thyroid pills. Life is good.