TY - JOUR T1 - Vitamin D deficiency in the 21st century: a persistent problem among Canadian infants and mothers JF - Canadian Medical Association Journal JO - CMAJ SP - 769 LP - 770 DO - 10.1503/cmaj.050177 VL - 172 IS - 6 AU - Leanne M. Ward Y1 - 2005/03/15 UR - http://www.cmaj.ca/content/172/6/769.abstract ER -