I get increased back pain from vitamin D supplements.
If you are above 20 ng/ml, you are not
deficient. Above 30 ng/ml there are signals in the research that your risk of cancer and cardiovascular disease starts to increase. Notable are increased risks for pancreatic and prostate cancer. Pancreatic cancer will kill you dead fast no matter what other measures you may have taken to increase longevity and health.
I am already at 30 ng/ml, and I take only 800 IU daily in a multi and don't get much sun.
Read the recent Institute of Medicine vitamin D report, which is freely available online. It is a recent meta-analysis of more than 1000 available research papers on vitamin D, so it is pretty much the state of the art of our current knowledge.
Quoted from the report:
Based on available data, almost all individuals get sufficient vitamin D when their blood levels are at or above 20 nanograms per milliliter as it is measured in America, or 50 nanomoles per liter as measured in Canada.
a pooled analysis of large cohort studies suggests an association for increased risk of pancreatic cancer with serum 25OHD levels greater than 100 nmol/L [U.S. units 40 ng/ml] that is not consistently seen in analyses of individual large cohorts.
Regarding prostate cancer, Tuohimaa et al. (2004) found a higher risk of prostate cancer for those with serum 25OHD levels above 80 nmol/L [U.S. units 32 ng/ml]. The subjects were 67 men, mostly from Norway. Although another study from Finland (Tuohimaa et al., 2004) also found an association between serum 25OHD levels and prostate cancer at levels above 80 nmol/L, a study conducted by Faupel-Badger et al. (2007) also in Finland did not find a relationship
Analysis of fully adjusted data indicated an inverse relationship between CVD mortality and baseline serum 25OHD level of 50.0 to 74.9 nmol/L. Risk began to increase at approximately 75 nmol/L [U.S. units 30 ng/ml] and then it declined after 100 nmol/L.
Edited by viveutvivas, 07 June 2012 - 09:03 PM.