February 26, 2013 5:46 am Calcium Supplements: Finding A Balance New guidelines shake up long held beliefs about calcium and Vitamin D supplements. NBC’s Erika Edwards reports. US & World Videos 1:02 Google productivity expert authors guide to boost wellness 2:23 Watch: Feeling and showing the impact of organ donation 1:07 Watch: Autism specialist discusses rise in children on the spectrum 1:10 Bay Area app monitors problems for people living with Parkinson's 1:43 Traces of bird flu virus found in 1 in 5 samples of pasteurized milk, FDA says