Date	Event	Description
23 May 2006	New search has been performed	Update 2006: One randomized double‐blind controlled trial (Hvas 2004) was found in the new search. This trial was performed on elderly with cognitive impairment and vitamin B12 deficiency. No data was available at the end of the treatment period, however, the follow‐up results at three months did not show any efficacy of B12 treatment on cognitive function.
25 May 2003	New citation required and conclusions have changed	Substantive amendment