Reinhold Vieth, PhD The cancer proliferation marker Ki-67
decreased significantly in men who took high-dose vitamin D in
the weeks leading up to radical prostatectomy for localized
prostate cancer, data from a small clinical study showed.1 The
decline in Ki-67 correlated with increasing serum and prostate
levels of calcitriol, which rose in a dose-dependent manner with
vitamin D, reaching the highest levels with the highest dose of
vitamin D (P Moreover, high-dose vitamin D was associated with
favorable changes in expression of micro- RNA (miRNA) involved
in tumor suppression. “This was early-phase clinical research,
essential to justify larger studies that would aim to prove that
vitamin D prolongs survival or prevents cancer,” Reinhold Vieth,
PhD, a clinical biochemist at the University of Toronto,
Ontario, Canada, said during a press conference at the 2012 AACR
Annual Meeting. “We still need to sort out the role of calcium,”
he added. “Currently, we predict that high calcium may be
adverse to the prostate