The investigators integrated data from NHANES and the USRDS database to examine the contribution of low 25 (OH) D levels (less than 15 ng/ml) to the incidence of ESRD over a median follow-up of 9 years. Participants were initially free of kidney disease, with under 0.5% having GFR less than 60ml/min or microalbuminuria at baseline.
Of 13,328 individuals, there were 62 cases of ESRD at follow-up. They observed a 2.6-fold increased risk of ESRD in those with 25 (OH) D levels under 15 ng/ml, after multivariable analysis. Further sub-analysis revealed that almost 60% of the excess risk of ESRD comonly seen in blacks was accounted for by low 25 (OH) D levels in their study.
It is presumed that blacks are predisposed to low vitamin D levels as a consequence of decreased synthesis in the skin due to pigmentation. Being very much at the other end of the skin tone spectrum, I'm not reaching for the multivitamins just yet: I'd like to see some interventional data first.