RT Journal Article SR Electronic T1 Nutritional vitamin D status during pregnancy: reasons for concern JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 1287 OP 1290 DO 10.1503/cmaj.060149 VO 174 IS 9 A1 Hollis, Bruce W. A1 Wagner, Carol L. YR 2006 UL http://www.cmaj.ca/content/174/9/1287.abstract