we measured 1,25-oh2d , vitamin d binding protein and related biochemical parameters and calculated the free 1,25-oh2d index in serum of 17 premature infants ( birthweight 810-1700 g ; gestational age 31-36 weeks ) on two different occasions defined by body weight ( study a : 1,750-1,850 g , study b : 2,100-2,200 g ) .
C0005612
birthweight
C0005910
body weight