RT Journal Article SR Electronic T1 Low vitamin D prevalence at the GP practice JF British Journal of General Practice JO Br J Gen Pract FD British Journal of General Practice SP 512 OP 512 DO 10.3399/bjgp15X686857 VO 65 IS 639 A1 Lee Wah Phin A1 John Holden YR 2015 UL http://bjgp.org/content/65/639/512.2.abstract AB