Cognitive function can be influenced by psychological (Santos et al.,2012 ), nutritional, medical (including medical conditions and prescription and nonprescription medications), social, economic, or behavioral, toxic environmental exposures, and genetic factors(Plassman et al., 2010) . As worldwide population aging, this topic increasingly interests researchers. There are thousands studies had done to find the specific factors associated with cognitive function, for instance loneliness (Boss, Kang, and Branson, 2015), exercise (Carvalho et al., 2014), neuroinflammation(Janssen et al., 2016), Mediterranean diet(Petersson …show more content…
For example, more than 2.9 million serum vitamin B12 tests were performed in 2010 in Ontario at a cost of $40 million.(Ogunkolade et al., 2013)
Vitamin B12(Cobalamine) is a group of compounds with corrinoid ring (4-pyrrole rings) with cobalt (Co). Vitamin B12 are synthesized exclusively by bacteria and have different functional groups chelated to Co. (University of Aberdeen, 2016)
Vitamin B12 and folate depend on each other for activation. Both vitamin B12 and folate are very important for DNA synthesis and cell replication.
The individual roles of vitamin B12 also essential for human beings. Vitamin B12 can maintain myelin sheath, promote normal growth of nerve cells, and be involved in bone cell metabolism/activity.
Vitamin B12 and folic acid reduce homocysteine to methionine, which is then converted into S-adenosylmethionine (SAM), a crucial co-factor for 150+ methyltransferases including glycine n-methyltransferase (GNMT) in the one carbon pathway.(Mitchell, Conus, and Kaput, 2014). Therefore, High levels of homocysteine (Hcy) are associated with low levels of B vitamins. (Quality, 2014). Hcy could cause cognitive impairment via direct neurotoxicity.(Morris, 2012; Bednarska-Makaruk et al., …show more content…
When the results using both cognitive tests were compared with vitamin B12 level and both MMMSE and MMMSE plus PFAQ have association with vitamin B12 level, p=0.002, p=0.008 respectively(Castillo-Lancellotti et al., 2015). As Castillo-Lancellotti et al., suggested, MMMSE may be a better measurement for estimating cognitive function(score≤13)(Folstein, Folstein, and McHugh,