  We present vanadium (V) abundances for 255 metal-poor stars, derived from
high-resolution optical spectra from the Magellan Inamori Kyocera Echelle
spectrograph on the Magellan Telescopes at Las Campanas Observatory, the Robert
G. Tull Coud\'{e} Spectrograph on the Harlan J. Smith Telescope at McDonald
Observatory, and the High Resolution Spectrograph on the Hobby-Eberly Telescope
at McDonald Observatory. We use updated V I and V II atomic transition data
from recent laboratory studies, and we increase the number of lines examined
(from 1 to 4 lines of V I, and from 2 to 7 lines of V II). As a result, we
reduce the V abundance uncertainties for most stars by more than 20% and expand
the number of stars with V detections from 204 to 255. In the metallicity range
$-$4.0 $<$ [Fe/H] $< -$1.0, we calculate the mean ratios [V I/Fe I]$ = -0.10
\pm 0.01 (\sigma = 0.16)$ from 128 stars with $\geq$ 2 V I lines detected, [V
II/Fe II] $= +0.13 \pm 0.01 (\sigma = 0.16)$ from 220 stars with $\geq$ 2 V II
lines detected, and [V II/V I] $= +0.25 \pm 0.01 (\sigma = 0.15)$ from 119
stars. We suspect this offset is due to non-LTE effects, and we recommend using
[V II/Fe II], which is enhanced relative to the solar ratio, as a better
representation of [V/Fe]. We provide more extensive evidence for abundance
correlations detected previously among scandium, titanium, and vanadium, and we
identify no systematic effects in the analysis that can explain these
correlations.

Solar and Stellar Astrophysics;Astrophysics of Galaxies