Robsahm TE, et al. - Given that an inverse association of circulating 25-hydroxyvitamin D (25-OHD) levels with cancer death has been reported, researchers examined this link using repeated measurements of serum 25-OHD. In population health surveys in Norway (1973–2004), they obtained prediagnostic serum samples. A second serum sample was taken from participants who subsequently developed cancer (1984–2004), at the time of cancer diagnosis. A significantly lower HRs (39–54%) of case fatality were reported for higher pre-diagnostic 25-OHD levels (≥ 46 nmol/L) vs low levels (< 46 nmol/L). In this study, a causal link between vitamin D and cancer case fatality was suggested.