RT Journal Article SR Electronic T1 Vitamin D testing: three important issues JF British Journal of General Practice JO Br J Gen Pract FD British Journal of General Practice SP 124 OP 124 DO 10.3399/bjgp14X677400 VO 64 IS 620 A1 Katy Gardner A1 Stephen Zhao YR 2014 UL http://bjgp.org/content/64/620/124.1.abstract AB