The vast majority of studies reported inverse associations between 25(OH)D concentration and all-cause mortality .
This association appeared to be non-linear , with progressively lower mortality with increasing 25(OH)D up to a point , beyond which there was no further decrease .
There is moderate evidence that vitamin D status is inversely associated with cancer mortality and death due to respiratory diseases , while for cardiovascular mortality , there is weak evidence of an association in observational studies , which is not supported by the data from intervention or Mendelian r and omization studies .
Epidemiological evidence suggests that vitamin D deficiency is associated with increased mortality , but it is unclear whether this is explained by reverse causation , and if there are specific causes of death for which vitamin D might be important .
Does liver damage explain the inverse association between vitamin D status and mortality?
PURPOSE Several observational studies have linked vitamin D deficiency with an increased risk of all cause mortality .  Vitamin D deficiency is common among patients with liver diseases . In a r and om sample of the general population , we investigated whether the inverse association between vitamin D status and all-cause mortality could be explained by liver damage as reflected by increased levels of liver enzymes . METHODS We included a total of 2649 persons examined in 1993e1994 . Vitamin D status was assessed as serum 25-hydroxyvitamin D and liver enzyme levels were measured . Information on all-cause mortality was obtained from the Danish Central Personal Register until July 2011 . Median follow-up time was 17.0 years , and there were 736 deaths . RESULTS Multivariable Cox regression analyses with age as underlying time axis and delayed entry showed lower mortality risk with higher vitamin D levels and this was essentially unaffected by adjustment for liver enzyme levels with hazard ratio , 0.96 ( 95 % confidence interval , 0.93e0.99 ) for a 10 nmol/L higher vitamin D level . CONCLUSIONS The present study did not support our hypothesis that the well-known association between low vitamin D status and mortality is explained by liver damage as reflected by levels of liver enzymes
The vast majority of studies reported inverse associations between 25(OH)D concentration and all-cause mortality .
This association appeared to be non-linear , with progressively lower mortality with increasing 25(OH)D up to a point , beyond which there was no further decrease .
There is moderate evidence that vitamin D status is inversely associated with cancer mortality and death due to respiratory diseases , while for cardiovascular mortality , there is weak evidence of an association in observational studies , which is not supported by the data from intervention or Mendelian r and omization studies .
Epidemiological evidence suggests that vitamin D deficiency is associated with increased mortality , but it is unclear whether this is explained by reverse causation , and if there are specific causes of death for which vitamin D might be important .